Merge branch 'static-transport-keys' into 'master'

Add database support for pending contacts and handshake keys

See merge request briar/briar!1078

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactExchangeTask.java

@@ -18,30 +18,30 @@ public interface ContactExchangeTask {
 	byte PROTOCOL_VERSION = 1;
 
 	/**
-	 * Label for deriving Alice's header key from the master secret.
+	 * Label for deriving Alice's header key from the master key.
 	 */
 	String ALICE_KEY_LABEL =
 			"org.briarproject.bramble.contact/ALICE_HEADER_KEY";
 
 	/**
-	 * Label for deriving Bob's header key from the master secret.
+	 * Label for deriving Bob's header key from the master key.
 	 */
 	String BOB_KEY_LABEL = "org.briarproject.bramble.contact/BOB_HEADER_KEY";
 
 	/**
-	 * Label for deriving Alice's key binding nonce from the master secret.
+	 * Label for deriving Alice's key binding nonce from the master key.
 	 */
 	String ALICE_NONCE_LABEL = "org.briarproject.bramble.contact/ALICE_NONCE";
 
 	/**
-	 * Label for deriving Bob's key binding nonce from the master secret.
+	 * Label for deriving Bob's key binding nonce from the master key.
 	 */
 	String BOB_NONCE_LABEL = "org.briarproject.bramble.contact/BOB_NONCE";
 
 	/**
 	 * Exchanges contact information with a remote peer.
 	 */
-	void startExchange(LocalAuthor localAuthor, SecretKey masterSecret,
+	void startExchange(LocalAuthor localAuthor, SecretKey masterKey,
 			DuplexTransportConnection conn, TransportId transportId,
 			boolean alice);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactManager.java

@@ -13,8 +13,6 @@ import java.util.Collection;
 
 import javax.annotation.Nullable;
 
-import static org.briarproject.bramble.api.contact.PendingContact.PendingContactState.FAILED;
-
 @NotNullByDefault
 public interface ContactManager {
 
@@ -33,7 +31,7 @@ public interface ContactManager {
 	 * @param alice true if the local party is Alice
 	 */
 	ContactId addContact(Transaction txn, Author remote, AuthorId local,
-			SecretKey master, long timestamp, boolean alice, boolean verified,
+			SecretKey rootKey, long timestamp, boolean alice, boolean verified,
 			boolean active) throws DbException;
 
 	/**
@@ -50,7 +48,7 @@ public interface ContactManager {
 	 *
 	 * @param alice true if the local party is Alice
 	 */
-	ContactId addContact(Author remote, AuthorId local, SecretKey master,
+	ContactId addContact(Author remote, AuthorId local, SecretKey rootKey,
 			long timestamp, boolean alice, boolean verified, boolean active)
 			throws DbException;
 
@@ -79,7 +77,8 @@ public interface ContactManager {
 	Collection<PendingContact> getPendingContacts();
 
 	/**
-	 * Removes a {@link PendingContact} that is in state {@link FAILED}.
+	 * Removes a {@link PendingContact} that is in state
+	 * {@link PendingContactState FAILED}.
 	 */
 	void removePendingContact(PendingContact pendingContact);
 

bramble-api/src/main/java/org/briarproject/bramble/api/contact/PendingContact.java

@@ -8,26 +8,29 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class PendingContact {
 
-	public enum PendingContactState {
-		WAITING_FOR_CONNECTION,
-		CONNECTED,
-		ADDING_CONTACT,
-		FAILED
-	}
-
 	private final PendingContactId id;
+	private final byte[] publicKey;
 	private final String alias;
 	private final PendingContactState state;
 	private final long timestamp;
 
-	public PendingContact(PendingContactId id, String alias,
+	public PendingContact(PendingContactId id, byte[] publicKey,
-			PendingContactState state, long timestamp) {
+			String alias, PendingContactState state, long timestamp) {
 		this.id = id;
+		this.publicKey = publicKey;
 		this.alias = alias;
 		this.state = state;
 		this.timestamp = timestamp;
 	}
 
+	public PendingContactId getId() {
+		return id;
+	}
+
+	public byte[] getPublicKey() {
+		return publicKey;
+	}
+
 	public String getAlias() {
 		return alias;
 	}
@@ -50,5 +53,4 @@ public class PendingContact {
 		return o instanceof PendingContact &&
 				id.equals(((PendingContact) o).id);
 	}
-
 }

bramble-api/src/main/java/org/briarproject/bramble/api/contact/PendingContactState.java

@@ -0,0 +1,30 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public enum PendingContactState {
+
+	WAITING_FOR_CONNECTION(0),
+	CONNECTED(1),
+	ADDING_CONTACT(2),
+	FAILED(3);
+
+	private final int value;
+
+	PendingContactState(int value) {
+		this.value = value;
+	}
+
+	public int getValue() {
+		return value;
+	}
+
+	public static PendingContactState fromValue(int value) {
+		for (PendingContactState s : values()) if (s.value == value) return s;
+		throw new IllegalArgumentException();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/PendingContactStateChangedEvent.java

@@ -1,7 +1,7 @@
 package org.briarproject.bramble.api.contact.event;
 
-import org.briarproject.bramble.api.contact.PendingContact.PendingContactState;
 import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.contact.PendingContactState;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/TransportCrypto.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.api.crypto;
 
 import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
 /**
@@ -11,19 +12,34 @@ public interface TransportCrypto {
 
 	/**
 	 * Derives initial transport keys for the given transport in the given
-	 * rotation period from the given master secret.
+	 * time period from the given root key.
 	 *
 	 * @param alice whether the keys are for use by Alice or Bob.
 	 * @param active whether the keys are usable for outgoing streams.
 	 */
-	TransportKeys deriveTransportKeys(TransportId t, SecretKey master,
+	TransportKeys deriveTransportKeys(TransportId t, SecretKey rootKey,
-			long rotationPeriod, boolean alice, boolean active);
+			long timePeriod, boolean alice, boolean active);
 
 	/**
-	 * Rotates the given transport keys to the given rotation period. If the
+	 * Rotates the given transport keys to the given time period. If the keys
-	 * keys are for the given period or any later period they are not rotated.
+	 * are for the given period or any later period they are not rotated.
 	 */
-	TransportKeys rotateTransportKeys(TransportKeys k, long rotationPeriod);
+	TransportKeys rotateTransportKeys(TransportKeys k, long timePeriod);
+
+	/**
+	 * Derives handshake keys for the given transport in the given time period
+	 * from the given root key.
+	 *
+	 * @param alice whether the keys are for use by Alice or Bob.
+	 */
+	HandshakeKeys deriveHandshakeKeys(TransportId t, SecretKey rootKey,
+			long timePeriod, boolean alice);
+
+	/**
+	 * Updates the given handshake keys to the given time period. If the keys
+	 * are for the given period or any later period they are not updated.
+	 */
+	HandshakeKeys updateHandshakeKeys(HandshakeKeys k, long timePeriod);
 
 	/**
 	 * Encodes the pseudo-random tag that is used to recognise a stream.

bramble-api/src/main/java/org/briarproject/bramble/api/db/DatabaseComponent.java

@@ -2,6 +2,8 @@ package org.briarproject.bramble.api.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
@@ -20,8 +22,11 @@ import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.Offer;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.validation.MessageState;
-import org.briarproject.bramble.api.transport.KeySet;
+import org.briarproject.bramble.api.transport.HandshakeKeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
 import java.util.Collection;
@@ -108,6 +113,20 @@ public interface DatabaseComponent {
 	 */
 	void addGroup(Transaction txn, Group g) throws DbException;
 
+	/**
+	 * Stores the given handshake keys for the given contact and returns a
+	 * key set ID.
+	 */
+	HandshakeKeySetId addHandshakeKeys(Transaction txn, ContactId c,
+			HandshakeKeys k) throws DbException;
+
+	/**
+	 * Stores the given handshake keys for the given pending contact and
+	 * returns a key set ID.
+	 */
+	HandshakeKeySetId addHandshakeKeys(Transaction txn, PendingContactId p,
+			HandshakeKeys k) throws DbException;
+
 	/**
 	 * Stores a local pseudonym.
 	 */
@@ -119,6 +138,12 @@ public interface DatabaseComponent {
 	void addLocalMessage(Transaction txn, Message m, Metadata meta,
 			boolean shared) throws DbException;
 
+	/**
+	 * Stores a pending contact.
+	 */
+	void addPendingContact(Transaction txn, PendingContact p)
+			throws DbException;
+
 	/**
 	 * Stores a transport.
 	 */
@@ -129,27 +154,41 @@ public interface DatabaseComponent {
 	 * Stores the given transport keys for the given contact and returns a
 	 * key set ID.
 	 */
-	KeySetId addTransportKeys(Transaction txn, ContactId c,
+	TransportKeySetId addTransportKeys(Transaction txn, ContactId c,
 			TransportKeys k) throws DbException;
 
 	/**
 	 * Returns true if the database contains the given contact for the given
 	 * local pseudonym.
+	 * <p/>
+	 * Read-only.
 	 */
 	boolean containsContact(Transaction txn, AuthorId remote, AuthorId local)
 			throws DbException;
 
 	/**
 	 * Returns true if the database contains the given group.
+	 * <p/>
+	 * Read-only.
 	 */
 	boolean containsGroup(Transaction txn, GroupId g) throws DbException;
 
 	/**
 	 * Returns true if the database contains the given local author.
+	 * <p/>
+	 * Read-only.
 	 */
 	boolean containsLocalAuthor(Transaction txn, AuthorId local)
 			throws DbException;
 
+	/**
+	 * Returns true if the database contains the given pending contact.
+	 * <p/>
+	 * Read-only.
+	 */
+	boolean containsPendingContact(Transaction txn, PendingContactId p)
+			throws DbException;
+
 	/**
 	 * Deletes the message with the given ID. Unlike
 	 * {@link #removeMessage(Transaction, MessageId)}, the message ID,
@@ -269,6 +308,14 @@ public interface DatabaseComponent {
 	Visibility getGroupVisibility(Transaction txn, ContactId c, GroupId g)
 			throws DbException;
 
+	/**
+	 * Returns all handshake keys for the given transport.
+	 * <p/>
+	 * Read-only.
+	 */
+	Collection<HandshakeKeySet> getHandshakeKeys(Transaction txn, TransportId t)
+			throws DbException;
+
 	/**
 	 * Returns the local pseudonym with the given ID.
 	 * <p/>
@@ -417,6 +464,14 @@ public interface DatabaseComponent {
 	 */
 	long getNextSendTime(Transaction txn, ContactId c) throws DbException;
 
+	/**
+	 * Returns all pending contacts.
+	 * <p/>
+	 * Read-only.
+	 */
+	Collection<PendingContact> getPendingContacts(Transaction txn)
+			throws DbException;
+
 	/**
 	 * Returns all settings in the given namespace.
 	 * <p/>
@@ -429,14 +484,20 @@ public interface DatabaseComponent {
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<KeySet> getTransportKeys(Transaction txn, TransportId t)
+	Collection<TransportKeySet> getTransportKeys(Transaction txn, TransportId t)
 			throws DbException;
 
+	/**
+	 * Increments the outgoing stream counter for the given handshake keys.
+	 */
+	void incrementStreamCounter(Transaction txn, TransportId t,
+			HandshakeKeySetId k) throws DbException;
+
 	/**
 	 * Increments the outgoing stream counter for the given transport keys.
 	 */
-	void incrementStreamCounter(Transaction txn, TransportId t, KeySetId k)
+	void incrementStreamCounter(Transaction txn, TransportId t,
-			throws DbException;
+			TransportKeySetId k) throws DbException;
 
 	/**
 	 * Merges the given metadata with the existing metadata for the given
@@ -491,6 +552,12 @@ public interface DatabaseComponent {
 	 */
 	void removeGroup(Transaction txn, Group g) throws DbException;
 
+	/**
+	 * Removes the given handshake keys from the database.
+	 */
+	void removeHandshakeKeys(Transaction txn, TransportId t,
+			HandshakeKeySetId k) throws DbException;
+
 	/**
 	 * Removes a local pseudonym (and all associated state) from the database.
 	 */
@@ -501,6 +568,12 @@ public interface DatabaseComponent {
 	 */
 	void removeMessage(Transaction txn, MessageId m) throws DbException;
 
+	/**
+	 * Removes a pending contact (and all associated state) from the database.
+	 */
+	void removePendingContact(Transaction txn, PendingContactId p)
+			throws DbException;
+
 	/**
 	 * Removes a transport (and all associated state) from the database.
 	 */
@@ -509,8 +582,8 @@ public interface DatabaseComponent {
 	/**
 	 * Removes the given transport keys from the database.
 	 */
-	void removeTransportKeys(Transaction txn, TransportId t, KeySetId k)
+	void removeTransportKeys(Transaction txn, TransportId t,
-			throws DbException;
+			TransportKeySetId k) throws DbException;
 
 	/**
 	 * Marks the given contact as verified.
@@ -553,21 +626,36 @@ public interface DatabaseComponent {
 			Collection<MessageId> dependencies) throws DbException;
 
 	/**
-	 * Sets the reordering window for the given key set and transport in the
+	 * Sets the reordering window for the given transport key set in the given
-	 * given rotation period.
+	 * time period.
 	 */
-	void setReorderingWindow(Transaction txn, KeySetId k, TransportId t,
+	void setReorderingWindow(Transaction txn, TransportKeySetId k,
-			long rotationPeriod, long base, byte[] bitmap) throws DbException;
+			TransportId t, long timePeriod, long base, byte[] bitmap)
+			throws DbException;
+
+	/**
+	 * Sets the reordering window for the given handshake key set in the given
+	 * time period.
+	 */
+	void setReorderingWindow(Transaction txn, HandshakeKeySetId k,
+			TransportId t, long timePeriod, long base, byte[] bitmap)
+			throws DbException;
 
 	/**
 	 * Marks the given transport keys as usable for outgoing streams.
 	 */
-	void setTransportKeysActive(Transaction txn, TransportId t, KeySetId k)
+	void setTransportKeysActive(Transaction txn, TransportId t,
+			TransportKeySetId k) throws DbException;
+
+	/**
+	 * Stores the given handshake keys, deleting any keys they have replaced.
+	 */
+	void updateHandshakeKeys(Transaction txn, Collection<HandshakeKeySet> keys)
 			throws DbException;
 
 	/**
 	 * Stores the given transport keys, deleting any keys they have replaced.
 	 */
-	void updateTransportKeys(Transaction txn, Collection<KeySet> keys)
+	void updateTransportKeys(Transaction txn, Collection<TransportKeySet> keys)
 			throws DbException;
 }

bramble-api/src/main/java/org/briarproject/bramble/api/db/NoSuchPendingContactException.java

@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api.db;
+
+/**
+ * Thrown when a database operation is attempted for a pending contact that is
+ * not in the database. This exception may occur due to concurrent updates and
+ * does not indicate a database error.
+ */
+public class NoSuchPendingContactException extends DbException {
+}

bramble-api/src/main/java/org/briarproject/bramble/api/db/PendingContactExistsException.java

@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api.db;
+
+/**
+ * Thrown when a duplicate pending contact is added to the database. This
+ * exception may occur due to concurrent updates and does not indicate a
+ * database error.
+ */
+public class PendingContactExistsException extends DbException {
+}

bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/KeyAgreementConstants.java

@@ -40,8 +40,8 @@ public interface KeyAgreementConstants {
 			"org.briarproject.bramble.keyagreement/SHARED_SECRET";
 
 	/**
-	 * Label for deriving the master secret.
+	 * Label for deriving the master key.
 	 */
-	String MASTER_SECRET_LABEL =
+	String MASTER_KEY_LABEL =
 			"org.briarproject.bramble.keyagreement/MASTER_SECRET";
 }

bramble-api/src/main/java/org/briarproject/bramble/api/transport/AbstractTransportKeys.java

@@ -0,0 +1,57 @@
+package org.briarproject.bramble.api.transport;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * Abstract superclass for {@link TransportKeys} and {@link HandshakeKeys}.
+ */
+@Immutable
+@NotNullByDefault
+public abstract class AbstractTransportKeys {
+
+	private final TransportId transportId;
+	private final IncomingKeys inPrev, inCurr, inNext;
+	private final OutgoingKeys outCurr;
+
+	AbstractTransportKeys(TransportId transportId, IncomingKeys inPrev,
+			IncomingKeys inCurr, IncomingKeys inNext, OutgoingKeys outCurr) {
+		if (inPrev.getTimePeriod() != outCurr.getTimePeriod() - 1)
+			throw new IllegalArgumentException();
+		if (inCurr.getTimePeriod() != outCurr.getTimePeriod())
+			throw new IllegalArgumentException();
+		if (inNext.getTimePeriod() != outCurr.getTimePeriod() + 1)
+			throw new IllegalArgumentException();
+		this.transportId = transportId;
+		this.inPrev = inPrev;
+		this.inCurr = inCurr;
+		this.inNext = inNext;
+		this.outCurr = outCurr;
+	}
+
+	public TransportId getTransportId() {
+		return transportId;
+	}
+
+	public IncomingKeys getPreviousIncomingKeys() {
+		return inPrev;
+	}
+
+	public IncomingKeys getCurrentIncomingKeys() {
+		return inCurr;
+	}
+
+	public IncomingKeys getNextIncomingKeys() {
+		return inNext;
+	}
+
+	public OutgoingKeys getCurrentOutgoingKeys() {
+		return outCurr;
+	}
+
+	public long getTimePeriod() {
+		return outCurr.getTimePeriod();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/HandshakeKeySet.java

@@ -0,0 +1,70 @@
+package org.briarproject.bramble.api.transport;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * A set of keys for handshaking with a given contact or pending contact over a
+ * given transport. Unlike a {@link TransportKeySet} these keys do not provide
+ * forward secrecy.
+ */
+@Immutable
+@NotNullByDefault
+public class HandshakeKeySet {
+
+	private final HandshakeKeySetId keySetId;
+	@Nullable
+	private final ContactId contactId;
+	@Nullable
+	private final PendingContactId pendingContactId;
+	private final HandshakeKeys keys;
+
+	public HandshakeKeySet(HandshakeKeySetId keySetId, ContactId contactId,
+			HandshakeKeys keys) {
+		this.keySetId = keySetId;
+		this.contactId = contactId;
+		this.keys = keys;
+		pendingContactId = null;
+	}
+
+	public HandshakeKeySet(HandshakeKeySetId keySetId,
+			PendingContactId pendingContactId, HandshakeKeys keys) {
+		this.keySetId = keySetId;
+		this.pendingContactId = pendingContactId;
+		this.keys = keys;
+		contactId = null;
+	}
+
+	public HandshakeKeySetId getKeySetId() {
+		return keySetId;
+	}
+
+	@Nullable
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+	@Nullable
+	public PendingContactId getPendingContactId() {
+		return pendingContactId;
+	}
+
+	public HandshakeKeys getKeys() {
+		return keys;
+	}
+
+	@Override
+	public int hashCode() {
+		return keySetId.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof HandshakeKeySet &&
+				keySetId.equals(((HandshakeKeySet) o).keySetId);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/HandshakeKeySetId.java

@@ -0,0 +1,36 @@
+package org.briarproject.bramble.api.transport;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * Type-safe wrapper for an integer that uniquely identifies a
+ * {@link HandshakeKeySet set of handshake keys} within the scope of the local
+ * device.
+ */
+@Immutable
+@NotNullByDefault
+public class HandshakeKeySetId {
+
+	private final int id;
+
+	public HandshakeKeySetId(int id) {
+		this.id = id;
+	}
+
+	public int getInt() {
+		return id;
+	}
+
+	@Override
+	public int hashCode() {
+		return id;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof HandshakeKeySetId &&
+				id == ((HandshakeKeySetId) o).id;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/HandshakeKeys.java

@@ -0,0 +1,36 @@
+package org.briarproject.bramble.api.transport;
+
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * Keys for handshaking with a given contact or pending contact over a given
+ * transport. Unlike {@link TransportKeys} these keys do not provide forward
+ * secrecy.
+ */
+@Immutable
+@NotNullByDefault
+public class HandshakeKeys extends AbstractTransportKeys {
+
+	private final SecretKey rootKey;
+	private final boolean alice;
+
+	public HandshakeKeys(TransportId transportId, IncomingKeys inPrev,
+			IncomingKeys inCurr, IncomingKeys inNext, OutgoingKeys outCurr,
+			SecretKey rootKey, boolean alice) {
+		super(transportId, inPrev, inCurr, inNext, outCurr);
+		this.rootKey = rootKey;
+		this.alice = alice;
+	}
+
+	public SecretKey getRootKey() {
+		return rootKey;
+	}
+
+	public boolean isAlice() {
+		return alice;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/IncomingKeys.java

@@ -9,27 +9,27 @@ import static org.briarproject.bramble.api.transport.TransportConstants.REORDERI
 
 /**
  * Contains transport keys for receiving streams from a given contact over a
- * given transport in a given rotation period.
+ * given transport in a given time period.
  */
 @Immutable
 @NotNullByDefault
 public class IncomingKeys {
 
 	private final SecretKey tagKey, headerKey;
-	private final long rotationPeriod, windowBase;
+	private final long timePeriod, windowBase;
 	private final byte[] windowBitmap;
 
 	public IncomingKeys(SecretKey tagKey, SecretKey headerKey,
-			long rotationPeriod) {
+			long timePeriod) {
-		this(tagKey, headerKey, rotationPeriod, 0,
+		this(tagKey, headerKey, timePeriod, 0,
 				new byte[REORDERING_WINDOW_SIZE / 8]);
 	}
 
 	public IncomingKeys(SecretKey tagKey, SecretKey headerKey,
-			long rotationPeriod, long windowBase, byte[] windowBitmap) {
+			long timePeriod, long windowBase, byte[] windowBitmap) {
 		this.tagKey = tagKey;
 		this.headerKey = headerKey;
-		this.rotationPeriod = rotationPeriod;
+		this.timePeriod = timePeriod;
 		this.windowBase = windowBase;
 		this.windowBitmap = windowBitmap;
 	}
@@ -42,8 +42,8 @@ public class IncomingKeys {
 		return headerKey;
 	}
 
-	public long getRotationPeriod() {
+	public long getTimePeriod() {
-		return rotationPeriod;
+		return timePeriod;
 	}
 
 	public long getWindowBase() {

bramble-api/src/main/java/org/briarproject/bramble/api/transport/KeyManager.java

@@ -27,14 +27,14 @@ public interface KeyManager {
 	 * @param alice true if the local party is Alice
 	 * @param active whether the derived keys can be used for outgoing streams
 	 */
-	Map<TransportId, KeySetId> addContact(Transaction txn, ContactId c,
+	Map<TransportId, TransportKeySetId> addContact(Transaction txn, ContactId c,
-			SecretKey master, long timestamp, boolean alice, boolean active)
+			SecretKey rootKey, long timestamp, boolean alice, boolean active)
 			throws DbException;
 
 	/**
 	 * Marks the given transport keys as usable for outgoing streams.
 	 */
-	void activateKeys(Transaction txn, Map<TransportId, KeySetId> keys)
+	void activateKeys(Transaction txn, Map<TransportId, TransportKeySetId> keys)
 			throws DbException;
 
 	/**

bramble-api/src/main/java/org/briarproject/bramble/api/transport/KeySet.java

@@ -1,47 +0,0 @@
-package org.briarproject.bramble.api.transport;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * A set of transport keys for communicating with a contact.
- */
-@Immutable
-@NotNullByDefault
-public class KeySet {
-
-	private final KeySetId keySetId;
-	private final ContactId contactId;
-	private final TransportKeys transportKeys;
-
-	public KeySet(KeySetId keySetId, ContactId contactId,
-			TransportKeys transportKeys) {
-		this.keySetId = keySetId;
-		this.contactId = contactId;
-		this.transportKeys = transportKeys;
-	}
-
-	public KeySetId getKeySetId() {
-		return keySetId;
-	}
-
-	public ContactId getContactId() {
-		return contactId;
-	}
-
-	public TransportKeys getTransportKeys() {
-		return transportKeys;
-	}
-
-	@Override
-	public int hashCode() {
-		return keySetId.hashCode();
-	}
-
-	@Override
-	public boolean equals(Object o) {
-		return o instanceof KeySet && keySetId.equals(((KeySet) o).keySetId);
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/OutgoingKeys.java

@@ -7,26 +7,26 @@ import javax.annotation.concurrent.Immutable;
 
 /**
  * Contains transport keys for sending streams to a given contact over a given
- * transport in a given rotation period.
+ * transport in a given time period.
  */
 @Immutable
 @NotNullByDefault
 public class OutgoingKeys {
 
 	private final SecretKey tagKey, headerKey;
-	private final long rotationPeriod, streamCounter;
+	private final long timePeriod, streamCounter;
 	private final boolean active;
 
 	public OutgoingKeys(SecretKey tagKey, SecretKey headerKey,
-			long rotationPeriod, boolean active) {
+			long timePeriod, boolean active) {
-		this(tagKey, headerKey, rotationPeriod, 0, active);
+		this(tagKey, headerKey, timePeriod, 0, active);
 	}
 
 	public OutgoingKeys(SecretKey tagKey, SecretKey headerKey,
-			long rotationPeriod, long streamCounter, boolean active) {
+			long timePeriod, long streamCounter, boolean active) {
 		this.tagKey = tagKey;
 		this.headerKey = headerKey;
-		this.rotationPeriod = rotationPeriod;
+		this.timePeriod = timePeriod;
 		this.streamCounter = streamCounter;
 		this.active = active;
 	}
@@ -39,8 +39,8 @@ public class OutgoingKeys {
 		return headerKey;
 	}
 
-	public long getRotationPeriod() {
+	public long getTimePeriod() {
-		return rotationPeriod;
+		return timePeriod;
 	}
 
 	public long getStreamCounter() {

bramble-api/src/main/java/org/briarproject/bramble/api/transport/TransportConstants.java

@@ -82,30 +82,58 @@ public interface TransportConstants {
 	int REORDERING_WINDOW_SIZE = 32;
 
 	/**
-	 * Label for deriving Alice's initial tag key from the master secret.
+	 * Label for deriving Alice's initial tag key from the root key in
+	 * rotation mode.
 	 */
 	String ALICE_TAG_LABEL = "org.briarproject.bramble.transport/ALICE_TAG_KEY";
 
 	/**
-	 * Label for deriving Bob's initial tag key from the master secret.
+	 * Label for deriving Bob's initial tag key from the root key in rotation
+	 * mode.
 	 */
 	String BOB_TAG_LABEL = "org.briarproject.bramble.transport/BOB_TAG_KEY";
 
 	/**
-	 * Label for deriving Alice's initial header key from the master secret.
+	 * Label for deriving Alice's initial header key from the root key in
+	 * rotation mode.
 	 */
 	String ALICE_HEADER_LABEL =
 			"org.briarproject.bramble.transport/ALICE_HEADER_KEY";
 
 	/**
-	 * Label for deriving Bob's initial header key from the master secret.
+	 * Label for deriving Bob's initial header key from the root key in
+	 * rotation mode.
 	 */
 	String BOB_HEADER_LABEL =
 			"org.briarproject.bramble.transport/BOB_HEADER_KEY";
 
 	/**
-	 * Label for deriving the next period's key in key rotation.
+	 * Label for deriving the next period's key in rotation mode.
 	 */
 	String ROTATE_LABEL = "org.briarproject.bramble.transport/ROTATE";
 
+	/**
+	 * Label for deriving Alice's tag key from the root key in handshake mode.
+	 */
+	String ALICE_HANDSHAKE_TAG_LABEL =
+			"org.briarproject.bramble.transport/ALICE_HANDSHAKE_TAG_KEY";
+
+	/**
+	 * Label for deriving Bob's tag key from the root key in handshake mode.
+	 */
+	String BOB_HANDSHAKE_TAG_LABEL =
+			"org.briarproject.bramble.transport/BOB_HANDSHAKE_TAG_KEY";
+
+	/**
+	 * Label for deriving Alice's header key from the root key in handshake
+	 * mode.
+	 */
+	String ALICE_HANDSHAKE_HEADER_LABEL =
+			"org.briarproject.bramble.transport/ALICE_HANDSHAKE_HEADER_KEY";
+
+	/**
+	 * Label for deriving Bob's header key from the root key in handshake mode.
+	 */
+	String BOB_HANDSHAKE_HEADER_LABEL =
+			"org.briarproject.bramble.transport/BOB_HANDSHAKE_HEADER_KEY";
 }

bramble-api/src/main/java/org/briarproject/bramble/api/transport/TransportKeySet.java

@@ -0,0 +1,49 @@
+package org.briarproject.bramble.api.transport;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * A set of keys for communicating with a given contact over a given transport.
+ * Unlike a {@link HandshakeKeySet} these keys provide forward secrecy.
+ */
+@Immutable
+@NotNullByDefault
+public class TransportKeySet {
+
+	private final TransportKeySetId keySetId;
+	private final ContactId contactId;
+	private final TransportKeys keys;
+
+	public TransportKeySet(TransportKeySetId keySetId, ContactId contactId,
+			TransportKeys keys) {
+		this.keySetId = keySetId;
+		this.contactId = contactId;
+		this.keys = keys;
+	}
+
+	public TransportKeySetId getKeySetId() {
+		return keySetId;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+	public TransportKeys getKeys() {
+		return keys;
+	}
+
+	@Override
+	public int hashCode() {
+		return keySetId.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof TransportKeySet &&
+				keySetId.equals(((TransportKeySet) o).keySetId);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/TransportKeySetId.java

@@ -5,18 +5,19 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import javax.annotation.concurrent.Immutable;
 
 /**
- * Type-safe wrapper for an integer that uniquely identifies a set of transport
+ * Type-safe wrapper for an integer that uniquely identifies a
- * keys within the scope of the local device.
+ * {@link TransportKeySet set of transport keys} within the scope of the local
+ * device.
  * <p/>
  * Key sets created on a given device must have increasing identifiers.
  */
 @Immutable
 @NotNullByDefault
-public class KeySetId {
+public class TransportKeySetId {
 
 	private final int id;
 
-	public KeySetId(int id) {
+	public TransportKeySetId(int id) {
 		this.id = id;
 	}
 
@@ -31,6 +32,7 @@ public class KeySetId {
 
 	@Override
 	public boolean equals(Object o) {
-		return o instanceof KeySetId && id == ((KeySetId) o).id;
+		return o instanceof TransportKeySetId &&
+				id == ((TransportKeySetId) o).id;
 	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/transport/TransportKeys.java

@@ -6,52 +6,15 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import javax.annotation.concurrent.Immutable;
 
 /**
- * Keys for communicating with a given contact over a given transport.
+ * Keys for communicating with a given contact over a given transport. Unlike
+ * {@link HandshakeKeys} these keys provide forward secrecy.
  */
 @Immutable
 @NotNullByDefault
-public class TransportKeys {
+public class TransportKeys extends AbstractTransportKeys {
-
-	private final TransportId transportId;
-	private final IncomingKeys inPrev, inCurr, inNext;
-	private final OutgoingKeys outCurr;
 
 	public TransportKeys(TransportId transportId, IncomingKeys inPrev,
 			IncomingKeys inCurr, IncomingKeys inNext, OutgoingKeys outCurr) {
-		if (inPrev.getRotationPeriod() != outCurr.getRotationPeriod() - 1)
+		super(transportId, inPrev, inCurr, inNext, outCurr);
-			throw new IllegalArgumentException();
-		if (inCurr.getRotationPeriod() != outCurr.getRotationPeriod())
-			throw new IllegalArgumentException();
-		if (inNext.getRotationPeriod() != outCurr.getRotationPeriod() + 1)
-			throw new IllegalArgumentException();
-		this.transportId = transportId;
-		this.inPrev = inPrev;
-		this.inCurr = inCurr;
-		this.inNext = inNext;
-		this.outCurr = outCurr;
-	}
-
-	public TransportId getTransportId() {
-		return transportId;
-	}
-
-	public IncomingKeys getPreviousIncomingKeys() {
-		return inPrev;
-	}
-
-	public IncomingKeys getCurrentIncomingKeys() {
-		return inCurr;
-	}
-
-	public IncomingKeys getNextIncomingKeys() {
-		return inNext;
-	}
-
-	public OutgoingKeys getCurrentOutgoingKeys() {
-		return outCurr;
-	}
-
-	public long getRotationPeriod() {
-		return outCurr.getRotationPeriod();
 	}
 }

bramble-api/src/test/java/org/briarproject/bramble/test/TestUtils.java

@@ -1,6 +1,8 @@
 package org.briarproject.bramble.test;
 
 import org.briarproject.bramble.api.UniqueId;
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
@@ -25,6 +27,7 @@ import java.util.Random;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import static java.util.Arrays.asList;
+import static org.briarproject.bramble.api.contact.PendingContactState.WAITING_FOR_CONNECTION;
 import static org.briarproject.bramble.api.identity.Author.FORMAT_VERSION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
@@ -140,6 +143,18 @@ public class TestUtils {
 		return new Message(id, groupId, timestamp, body);
 	}
 
+	public static PendingContact getPendingContact() {
+		return getPendingContact(1 + random.nextInt(MAX_AUTHOR_NAME_LENGTH));
+	}
+
+	public static PendingContact getPendingContact(int nameLength) {
+		PendingContactId id = new PendingContactId(getRandomId());
+		byte[] publicKey = getRandomBytes(MAX_PUBLIC_KEY_LENGTH);
+		String alias = getRandomString(nameLength);
+		return new PendingContact(id, publicKey, alias, WAITING_FOR_CONNECTION,
+				timestamp);
+	}
+
 	public static double getMedian(Collection<? extends Number> samples) {
 		int size = samples.size();
 		if (size == 0) throw new IllegalArgumentException();

bramble-core/src/main/java/org/briarproject/bramble/contact/ContactExchangeTaskImpl.java

@@ -77,7 +77,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	private volatile LocalAuthor localAuthor;
 	private volatile DuplexTransportConnection conn;
 	private volatile TransportId transportId;
-	private volatile SecretKey masterSecret;
+	private volatile SecretKey masterKey;
 	private volatile boolean alice;
 
 	@Inject
@@ -104,13 +104,13 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	}
 
 	@Override
-	public void startExchange(LocalAuthor localAuthor, SecretKey masterSecret,
+	public void startExchange(LocalAuthor localAuthor, SecretKey masterKey,
 			DuplexTransportConnection conn, TransportId transportId,
 			boolean alice) {
 		this.localAuthor = localAuthor;
 		this.conn = conn;
 		this.transportId = transportId;
-		this.masterSecret = masterSecret;
+		this.masterKey = masterKey;
 		this.alice = alice;
 		start();
 	}
@@ -142,9 +142,9 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 		}
 
 		// Derive the header keys for the transport streams
-		SecretKey aliceHeaderKey = crypto.deriveKey(ALICE_KEY_LABEL,
+		SecretKey aliceHeaderKey = crypto.deriveKey(ALICE_KEY_LABEL, masterKey,
-				masterSecret, new byte[] {PROTOCOL_VERSION});
+				new byte[] {PROTOCOL_VERSION});
-		SecretKey bobHeaderKey = crypto.deriveKey(BOB_KEY_LABEL, masterSecret,
+		SecretKey bobHeaderKey = crypto.deriveKey(BOB_KEY_LABEL, masterKey,
 				new byte[] {PROTOCOL_VERSION});
 
 		// Create the readers
@@ -163,9 +163,9 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 						.createRecordWriter(streamWriter.getOutputStream());
 
 		// Derive the nonces to be signed
-		byte[] aliceNonce = crypto.mac(ALICE_NONCE_LABEL, masterSecret,
+		byte[] aliceNonce = crypto.mac(ALICE_NONCE_LABEL, masterKey,
 				new byte[] {PROTOCOL_VERSION});
-		byte[] bobNonce = crypto.mac(BOB_NONCE_LABEL, masterSecret,
+		byte[] bobNonce = crypto.mac(BOB_NONCE_LABEL, masterKey,
 				new byte[] {PROTOCOL_VERSION});
 		byte[] localNonce = alice ? aliceNonce : bobNonce;
 		byte[] remoteNonce = alice ? bobNonce : aliceNonce;
@@ -293,7 +293,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 			throws DbException {
 		return db.transactionWithResult(false, txn -> {
 			ContactId contactId = contactManager.addContact(txn, remoteAuthor,
-					localAuthor.getId(), masterSecret, timestamp, alice,
+					localAuthor.getId(), masterKey, timestamp, alice,
 					true, true);
 			transportPropertyManager.addRemoteProperties(txn, contactId,
 					remoteProperties);

bramble-core/src/main/java/org/briarproject/bramble/contact/ContactManagerImpl.java

@@ -30,8 +30,9 @@ import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
 import static java.util.Collections.emptyList;
-import static org.briarproject.bramble.api.contact.PendingContact.PendingContactState.WAITING_FOR_CONNECTION;
+import static org.briarproject.bramble.api.contact.PendingContactState.WAITING_FOR_CONNECTION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
+import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.OURSELVES;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNKNOWN;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNVERIFIED;
@@ -69,10 +70,10 @@ class ContactManagerImpl implements ContactManager {
 
 	@Override
 	public ContactId addContact(Transaction txn, Author remote, AuthorId local,
-			SecretKey master, long timestamp, boolean alice, boolean verified,
+			SecretKey rootKey, long timestamp, boolean alice, boolean verified,
 			boolean active) throws DbException {
 		ContactId c = db.addContact(txn, remote, local, verified, active);
-		keyManager.addContact(txn, c, master, timestamp, alice, active);
+		keyManager.addContact(txn, c, rootKey, timestamp, alice, active);
 		Contact contact = db.getContact(txn, c);
 		for (ContactHook hook : hooks) hook.addingContact(txn, contact);
 		return c;
@@ -88,11 +89,11 @@ class ContactManagerImpl implements ContactManager {
 	}
 
 	@Override
-	public ContactId addContact(Author remote, AuthorId local, SecretKey master,
+	public ContactId addContact(Author remote, AuthorId local,
-			long timestamp, boolean alice, boolean verified, boolean active)
+			SecretKey rootKey, long timestamp, boolean alice, boolean verified,
-			throws DbException {
+			boolean active) throws DbException {
 		return db.transactionWithResult(false, txn ->
-				addContact(txn, remote, local, master, timestamp, alice,
+				addContact(txn, remote, local, rootKey, timestamp, alice,
 						verified, active));
 	}
 
@@ -123,8 +124,8 @@ class ContactManagerImpl implements ContactManager {
 	public PendingContact addRemoteContactRequest(String link, String alias) {
 		// TODO replace with real implementation
 		PendingContactId id = new PendingContactId(link.getBytes());
-		return new PendingContact(id, alias, WAITING_FOR_CONNECTION,
+		return new PendingContact(id, new byte[MAX_PUBLIC_KEY_LENGTH], alias,
-				System.currentTimeMillis());
+				WAITING_FOR_CONNECTION, System.currentTimeMillis());
 	}
 
 	@Override

bramble-core/src/main/java/org/briarproject/bramble/crypto/TransportCryptoImpl.java

@@ -4,18 +4,22 @@ import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.TransportCrypto;
 import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
 import org.briarproject.bramble.api.transport.IncomingKeys;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
 import org.briarproject.bramble.api.transport.TransportKeys;
-import org.briarproject.bramble.util.ByteUtils;
-import org.briarproject.bramble.util.StringUtils;
 import org.spongycastle.crypto.Digest;
 import org.spongycastle.crypto.digests.Blake2bDigest;
 
 import javax.inject.Inject;
 
+import static java.lang.System.arraycopy;
+import static org.briarproject.bramble.api.transport.TransportConstants.ALICE_HANDSHAKE_HEADER_LABEL;
+import static org.briarproject.bramble.api.transport.TransportConstants.ALICE_HANDSHAKE_TAG_LABEL;
 import static org.briarproject.bramble.api.transport.TransportConstants.ALICE_HEADER_LABEL;
 import static org.briarproject.bramble.api.transport.TransportConstants.ALICE_TAG_LABEL;
+import static org.briarproject.bramble.api.transport.TransportConstants.BOB_HANDSHAKE_HEADER_LABEL;
+import static org.briarproject.bramble.api.transport.TransportConstants.BOB_HANDSHAKE_TAG_LABEL;
 import static org.briarproject.bramble.api.transport.TransportConstants.BOB_HEADER_LABEL;
 import static org.briarproject.bramble.api.transport.TransportConstants.BOB_TAG_LABEL;
 import static org.briarproject.bramble.api.transport.TransportConstants.ROTATE_LABEL;
@@ -24,6 +28,9 @@ import static org.briarproject.bramble.util.ByteUtils.INT_16_BYTES;
 import static org.briarproject.bramble.util.ByteUtils.INT_64_BYTES;
 import static org.briarproject.bramble.util.ByteUtils.MAX_16_BIT_UNSIGNED;
 import static org.briarproject.bramble.util.ByteUtils.MAX_32_BIT_UNSIGNED;
+import static org.briarproject.bramble.util.ByteUtils.writeUint16;
+import static org.briarproject.bramble.util.ByteUtils.writeUint64;
+import static org.briarproject.bramble.util.StringUtils.toUtf8;
 
 class TransportCryptoImpl implements TransportCrypto {
 
@@ -36,45 +43,44 @@ class TransportCryptoImpl implements TransportCrypto {
 
 	@Override
 	public TransportKeys deriveTransportKeys(TransportId t,
-			SecretKey master, long rotationPeriod, boolean alice,
+			SecretKey rootKey, long timePeriod, boolean weAreAlice,
 			boolean active) {
-		// Keys for the previous period are derived from the master secret
+		// Keys for the previous period are derived from the root key
-		SecretKey inTagPrev = deriveTagKey(master, t, !alice);
+		SecretKey inTagPrev = deriveTagKey(rootKey, t, !weAreAlice);
-		SecretKey inHeaderPrev = deriveHeaderKey(master, t, !alice);
+		SecretKey inHeaderPrev = deriveHeaderKey(rootKey, t, !weAreAlice);
-		SecretKey outTagPrev = deriveTagKey(master, t, alice);
+		SecretKey outTagPrev = deriveTagKey(rootKey, t, weAreAlice);
-		SecretKey outHeaderPrev = deriveHeaderKey(master, t, alice);
+		SecretKey outHeaderPrev = deriveHeaderKey(rootKey, t, weAreAlice);
 		// Derive the keys for the current and next periods
-		SecretKey inTagCurr = rotateKey(inTagPrev, rotationPeriod);
+		SecretKey inTagCurr = rotateKey(inTagPrev, timePeriod);
-		SecretKey inHeaderCurr = rotateKey(inHeaderPrev, rotationPeriod);
+		SecretKey inHeaderCurr = rotateKey(inHeaderPrev, timePeriod);
-		SecretKey inTagNext = rotateKey(inTagCurr, rotationPeriod + 1);
+		SecretKey inTagNext = rotateKey(inTagCurr, timePeriod + 1);
-		SecretKey inHeaderNext = rotateKey(inHeaderCurr, rotationPeriod + 1);
+		SecretKey inHeaderNext = rotateKey(inHeaderCurr, timePeriod + 1);
-		SecretKey outTagCurr = rotateKey(outTagPrev, rotationPeriod);
+		SecretKey outTagCurr = rotateKey(outTagPrev, timePeriod);
-		SecretKey outHeaderCurr = rotateKey(outHeaderPrev, rotationPeriod);
+		SecretKey outHeaderCurr = rotateKey(outHeaderPrev, timePeriod);
 		// Initialise the reordering windows and stream counters
 		IncomingKeys inPrev = new IncomingKeys(inTagPrev, inHeaderPrev,
-				rotationPeriod - 1);
+				timePeriod - 1);
 		IncomingKeys inCurr = new IncomingKeys(inTagCurr, inHeaderCurr,
-				rotationPeriod);
+				timePeriod);
 		IncomingKeys inNext = new IncomingKeys(inTagNext, inHeaderNext,
-				rotationPeriod + 1);
+				timePeriod + 1);
 		OutgoingKeys outCurr = new OutgoingKeys(outTagCurr, outHeaderCurr,
-				rotationPeriod, active);
+				timePeriod, active);
 		// Collect and return the keys
 		return new TransportKeys(t, inPrev, inCurr, inNext, outCurr);
 	}
 
 	@Override
-	public TransportKeys rotateTransportKeys(TransportKeys k,
+	public TransportKeys rotateTransportKeys(TransportKeys k, long timePeriod) {
-			long rotationPeriod) {
+		if (k.getTimePeriod() >= timePeriod) return k;
-		if (k.getRotationPeriod() >= rotationPeriod) return k;
 		IncomingKeys inPrev = k.getPreviousIncomingKeys();
 		IncomingKeys inCurr = k.getCurrentIncomingKeys();
 		IncomingKeys inNext = k.getNextIncomingKeys();
 		OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
-		long startPeriod = outCurr.getRotationPeriod();
+		long startPeriod = outCurr.getTimePeriod();
 		boolean active = outCurr.isActive();
 		// Rotate the keys
-		for (long p = startPeriod + 1; p <= rotationPeriod; p++) {
+		for (long p = startPeriod + 1; p <= timePeriod; p++) {
 			inPrev = inCurr;
 			inCurr = inNext;
 			SecretKey inNextTag = rotateKey(inNext.getTagKey(), p + 1);
@@ -89,24 +95,117 @@ class TransportCryptoImpl implements TransportCrypto {
 				outCurr);
 	}
 
-	private SecretKey rotateKey(SecretKey k, long rotationPeriod) {
+	private SecretKey rotateKey(SecretKey k, long timePeriod) {
 		byte[] period = new byte[INT_64_BYTES];
-		ByteUtils.writeUint64(rotationPeriod, period, 0);
+		writeUint64(timePeriod, period, 0);
 		return crypto.deriveKey(ROTATE_LABEL, k, period);
 	}
 
-	private SecretKey deriveTagKey(SecretKey master, TransportId t,
+	private SecretKey deriveTagKey(SecretKey rootKey, TransportId t,
-			boolean alice) {
+			boolean keyBelongsToAlice) {
-		String label = alice ? ALICE_TAG_LABEL : BOB_TAG_LABEL;
+		String label = keyBelongsToAlice ? ALICE_TAG_LABEL : BOB_TAG_LABEL;
-		byte[] id = StringUtils.toUtf8(t.getString());
+		byte[] id = toUtf8(t.getString());
-		return crypto.deriveKey(label, master, id);
+		return crypto.deriveKey(label, rootKey, id);
 	}
 
-	private SecretKey deriveHeaderKey(SecretKey master, TransportId t,
+	private SecretKey deriveHeaderKey(SecretKey rootKey, TransportId t,
-			boolean alice) {
+			boolean keyBelongsToAlice) {
-		String label = alice ? ALICE_HEADER_LABEL : BOB_HEADER_LABEL;
+		String label = keyBelongsToAlice ? ALICE_HEADER_LABEL :
-		byte[] id = StringUtils.toUtf8(t.getString());
+				BOB_HEADER_LABEL;
-		return crypto.deriveKey(label, master, id);
+		byte[] id = toUtf8(t.getString());
+		return crypto.deriveKey(label, rootKey, id);
+	}
+
+	@Override
+	public HandshakeKeys deriveHandshakeKeys(TransportId t, SecretKey rootKey,
+			long timePeriod, boolean weAreAlice) {
+		if (timePeriod < 1) throw new IllegalArgumentException();
+		IncomingKeys inPrev = deriveIncomingHandshakeKeys(t, rootKey,
+				weAreAlice, timePeriod - 1);
+		IncomingKeys inCurr = deriveIncomingHandshakeKeys(t, rootKey,
+				weAreAlice, timePeriod);
+		IncomingKeys inNext = deriveIncomingHandshakeKeys(t, rootKey,
+				weAreAlice, timePeriod + 1);
+		OutgoingKeys outCurr = deriveOutgoingHandshakeKeys(t, rootKey,
+				weAreAlice, timePeriod);
+		return new HandshakeKeys(t, inPrev, inCurr, inNext, outCurr, rootKey,
+				weAreAlice);
+	}
+
+	private IncomingKeys deriveIncomingHandshakeKeys(TransportId t,
+			SecretKey rootKey, boolean weAreAlice, long timePeriod) {
+		SecretKey tag = deriveHandshakeTagKey(t, rootKey, !weAreAlice,
+				timePeriod);
+		SecretKey header = deriveHandshakeHeaderKey(t, rootKey, !weAreAlice,
+				timePeriod);
+		return new IncomingKeys(tag, header, timePeriod);
+	}
+
+	private OutgoingKeys deriveOutgoingHandshakeKeys(TransportId t,
+			SecretKey rootKey, boolean weAreAlice, long timePeriod) {
+		SecretKey tag = deriveHandshakeTagKey(t, rootKey, weAreAlice,
+				timePeriod);
+		SecretKey header = deriveHandshakeHeaderKey(t, rootKey, weAreAlice,
+				timePeriod);
+		return new OutgoingKeys(tag, header, timePeriod, true);
+	}
+
+	private SecretKey deriveHandshakeTagKey(TransportId t, SecretKey rootKey,
+			boolean keyBelongsToAlice, long timePeriod) {
+		String label = keyBelongsToAlice ? ALICE_HANDSHAKE_TAG_LABEL :
+				BOB_HANDSHAKE_TAG_LABEL;
+		byte[] id = toUtf8(t.getString());
+		byte[] period = new byte[INT_64_BYTES];
+		writeUint64(timePeriod, period, 0);
+		return crypto.deriveKey(label, rootKey, id, period);
+	}
+
+	private SecretKey deriveHandshakeHeaderKey(TransportId t, SecretKey rootKey,
+			boolean keyBelongsToAlice, long timePeriod) {
+		String label = keyBelongsToAlice ? ALICE_HANDSHAKE_HEADER_LABEL :
+				BOB_HANDSHAKE_HEADER_LABEL;
+		byte[] id = toUtf8(t.getString());
+		byte[] period = new byte[INT_64_BYTES];
+		writeUint64(timePeriod, period, 0);
+		return crypto.deriveKey(label, rootKey, id, period);
+	}
+
+	@Override
+	public HandshakeKeys updateHandshakeKeys(HandshakeKeys k, long timePeriod) {
+		long elapsed = timePeriod - k.getTimePeriod();
+		TransportId t = k.getTransportId();
+		SecretKey rootKey = k.getRootKey();
+		boolean weAreAlice = k.isAlice();
+		if (elapsed <= 0) {
+			// The keys are for the given period or later - don't update them
+			return k;
+		} else if (elapsed == 1) {
+			// The keys are one period old - shift by one period, keeping the
+			// reordering windows for keys we retain
+			IncomingKeys inPrev = k.getCurrentIncomingKeys();
+			IncomingKeys inCurr = k.getNextIncomingKeys();
+			IncomingKeys inNext = deriveIncomingHandshakeKeys(t, rootKey,
+					weAreAlice, timePeriod + 1);
+			OutgoingKeys outCurr = deriveOutgoingHandshakeKeys(t, rootKey,
+					weAreAlice, timePeriod);
+			return new HandshakeKeys(t, inPrev, inCurr, inNext, outCurr,
+					rootKey, weAreAlice);
+		} else if (elapsed == 2) {
+			// The keys are two periods old - shift by two periods, keeping
+			// the reordering windows for keys we retain
+			IncomingKeys inPrev = k.getNextIncomingKeys();
+			IncomingKeys inCurr = deriveIncomingHandshakeKeys(t, rootKey,
+					weAreAlice, timePeriod);
+			IncomingKeys inNext = deriveIncomingHandshakeKeys(t, rootKey,
+					weAreAlice, timePeriod + 1);
+			OutgoingKeys outCurr = deriveOutgoingHandshakeKeys(t, rootKey,
+					weAreAlice, timePeriod);
+			return new HandshakeKeys(t, inPrev, inCurr, inNext, outCurr,
+					rootKey, weAreAlice);
+		} else {
+			// The keys are more than two periods old - derive fresh keys
+			return deriveHandshakeKeys(t, rootKey, timePeriod, weAreAlice);
+		}
 	}
 
 	@Override
@@ -125,14 +224,14 @@ class TransportCryptoImpl implements TransportCrypto {
 		// The input is the protocol version as a 16-bit integer, followed by
 		// the stream number as a 64-bit integer
 		byte[] protocolVersionBytes = new byte[INT_16_BYTES];
-		ByteUtils.writeUint16(protocolVersion, protocolVersionBytes, 0);
+		writeUint16(protocolVersion, protocolVersionBytes, 0);
 		prf.update(protocolVersionBytes, 0, protocolVersionBytes.length);
 		byte[] streamNumberBytes = new byte[INT_64_BYTES];
-		ByteUtils.writeUint64(streamNumber, streamNumberBytes, 0);
+		writeUint64(streamNumber, streamNumberBytes, 0);
 		prf.update(streamNumberBytes, 0, streamNumberBytes.length);
 		byte[] mac = new byte[macLength];
 		prf.doFinal(mac, 0);
 		// The output is the first TAG_LENGTH bytes of the MAC
-		System.arraycopy(mac, 0, tag, 0, TAG_LENGTH);
+		arraycopy(mac, 0, tag, 0, TAG_LENGTH);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/db/Database.java

@@ -2,9 +2,13 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.contact.PendingContactState;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DataTooNewException;
 import org.briarproject.bramble.api.db.DataTooOldException;
+import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.MessageDeletedException;
 import org.briarproject.bramble.api.db.Metadata;
@@ -23,8 +27,11 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.validation.MessageState;
-import org.briarproject.bramble.api.transport.KeySet;
+import org.briarproject.bramble.api.transport.HandshakeKeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
 import java.util.Collection;
@@ -33,11 +40,14 @@ import java.util.Map;
 import javax.annotation.Nullable;
 
 /**
- * A low-level interface to the database (DatabaseComponent provides a
+ * A low-level interface to the database ({@link DatabaseComponent} provides a
- * high-level interface). Most operations take a transaction argument, which is
+ * high-level interface).
- * obtained by calling {@link #startTransaction()}. Every transaction must be
+ * <p/>
- * terminated by calling either {@link #abortTransaction(Object) abortTransaction(T)} or
+ * Most operations take a transaction argument, which is obtained by calling
- * {@link #commitTransaction(Object) commitTransaction(T)}, even if an exception is thrown.
+ * {@link #startTransaction()}. Every transaction must be terminated by calling
+ * either {@link #abortTransaction(Object) abortTransaction(T)} or
+ * {@link #commitTransaction(Object) commitTransaction(T)}, even if an
+ * exception is thrown.
  */
 @NotNullByDefault
 interface Database<T> {
@@ -95,6 +105,20 @@ interface Database<T> {
 	void addGroupVisibility(T txn, ContactId c, GroupId g, boolean shared)
 			throws DbException;
 
+	/**
+	 * Stores the given handshake keys for the given contact and returns a
+	 * key set ID.
+	 */
+	HandshakeKeySetId addHandshakeKeys(T txn, ContactId c, HandshakeKeys k)
+			throws DbException;
+
+	/**
+	 * Stores the given handshake keys for the given pending contact and
+	 * returns a key set ID.
+	 */
+	HandshakeKeySetId addHandshakeKeys(T txn, PendingContactId p,
+			HandshakeKeys k) throws DbException;
+
 	/**
 	 * Stores a local pseudonym.
 	 */
@@ -121,6 +145,11 @@ interface Database<T> {
 	 */
 	void addOfferedMessage(T txn, ContactId c, MessageId m) throws DbException;
 
+	/**
+	 * Stores a pending contact.
+	 */
+	void addPendingContact(T txn, PendingContact p) throws DbException;
+
 	/**
 	 * Stores a transport.
 	 */
@@ -131,7 +160,7 @@ interface Database<T> {
 	 * Stores the given transport keys for the given contact and returns a
 	 * key set ID.
 	 */
-	KeySetId addTransportKeys(T txn, ContactId c, TransportKeys k)
+	TransportKeySetId addTransportKeys(T txn, ContactId c, TransportKeys k)
 			throws DbException;
 
 	/**
@@ -171,6 +200,14 @@ interface Database<T> {
 	 */
 	boolean containsMessage(T txn, MessageId m) throws DbException;
 
+	/**
+	 * Returns true if the database contains the given pending contact.
+	 * <p/>
+	 * Read-only.
+	 */
+	boolean containsPendingContact(T txn, PendingContactId p)
+			throws DbException;
+
 	/**
 	 * Returns true if the database contains the given transport.
 	 * <p/>
@@ -277,6 +314,14 @@ interface Database<T> {
 	Map<ContactId, Boolean> getGroupVisibility(T txn, GroupId g)
 			throws DbException;
 
+	/**
+	 * Returns all handshake keys for the given transport.
+	 * <p/>
+	 * Read-only.
+	 */
+	Collection<HandshakeKeySet> getHandshakeKeys(T txn, TransportId t)
+			throws DbException;
+
 	/**
 	 * Returns the local pseudonym with the given ID.
 	 * <p/>
@@ -467,6 +512,13 @@ interface Database<T> {
 	 */
 	long getNextSendTime(T txn, ContactId c) throws DbException;
 
+	/**
+	 * Returns all pending contacts.
+	 * <p/>
+	 * Read-only.
+	 */
+	Collection<PendingContact> getPendingContacts(T txn) throws DbException;
+
 	/**
 	 * Returns the IDs of some messages that are eligible to be sent to the
 	 * given contact and have been requested by the contact, up to the given
@@ -489,13 +541,19 @@ interface Database<T> {
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<KeySet> getTransportKeys(T txn, TransportId t)
+	Collection<TransportKeySet> getTransportKeys(T txn, TransportId t)
+			throws DbException;
+
+	/**
+	 * Increments the outgoing stream counter for the given handshake keys.
+	 */
+	void incrementStreamCounter(T txn, TransportId t, HandshakeKeySetId k)
 			throws DbException;
 
 	/**
 	 * Increments the outgoing stream counter for the given transport keys.
 	 */
-	void incrementStreamCounter(T txn, TransportId t, KeySetId k)
+	void incrementStreamCounter(T txn, TransportId t, TransportKeySetId k)
 			throws DbException;
 
 	/**
@@ -564,6 +622,12 @@ interface Database<T> {
 	void removeGroupVisibility(T txn, ContactId c, GroupId g)
 			throws DbException;
 
+	/**
+	 * Removes the given handshake keys from the database.
+	 */
+	void removeHandshakeKeys(T txn, TransportId t, HandshakeKeySetId k)
+			throws DbException;
+
 	/**
 	 * Removes a local pseudonym (and all associated state) from the database.
 	 */
@@ -581,6 +645,11 @@ interface Database<T> {
 	void removeOfferedMessages(T txn, ContactId c,
 			Collection<MessageId> requested) throws DbException;
 
+	/**
+	 * Removes a pending contact (and all associated state) from the database.
+	 */
+	void removePendingContact(T txn, PendingContactId p) throws DbException;
+
 	/**
 	 * Removes a transport (and all associated state) from the database.
 	 */
@@ -589,7 +658,7 @@ interface Database<T> {
 	/**
 	 * Removes the given transport keys from the database.
 	 */
-	void removeTransportKeys(T txn, TransportId t, KeySetId k)
+	void removeTransportKeys(T txn, TransportId t, TransportKeySetId k)
 			throws DbException;
 
 	/**
@@ -634,16 +703,29 @@ interface Database<T> {
 			throws DbException;
 
 	/**
-	 * Sets the reordering window for the given key set and transport in the
+	 * Sets the state of the given pending contact.
-	 * given rotation period.
 	 */
-	void setReorderingWindow(T txn, KeySetId k, TransportId t,
+	void setPendingContactState(T txn, PendingContactId p,
-			long rotationPeriod, long base, byte[] bitmap) throws DbException;
+			PendingContactState state) throws DbException;
+
+	/**
+	 * Sets the reordering window for the given transport key set in the given
+	 * time period.
+	 */
+	void setReorderingWindow(T txn, TransportKeySetId k, TransportId t,
+			long timePeriod, long base, byte[] bitmap) throws DbException;
+
+	/**
+	 * Sets the reordering window for the given handshake key set in the given
+	 * time period.
+	 */
+	void setReorderingWindow(T txn, HandshakeKeySetId k, TransportId t,
+			long timePeriod, long base, byte[] bitmap) throws DbException;
 
 	/**
 	 * Marks the given transport keys as usable for outgoing streams.
 	 */
-	void setTransportKeysActive(T txn, TransportId t, KeySetId k)
+	void setTransportKeysActive(T txn, TransportId t, TransportKeySetId k)
 			throws DbException;
 
 	/**
@@ -654,8 +736,13 @@ interface Database<T> {
 	void updateExpiryTimeAndEta(T txn, ContactId c, MessageId m, int maxLatency)
 			throws DbException;
 
+	/**
+	 * Updates the given handshake keys.
+	 */
+	void updateHandshakeKeys(T txn, HandshakeKeySet ks) throws DbException;
+
 	/**
 	 * Updates the given transport keys following key rotation.
 	 */
-	void updateTransportKeys(T txn, KeySet ks) throws DbException;
+	void updateTransportKeys(T txn, TransportKeySet ks) throws DbException;
 }

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseComponentImpl.java

@@ -2,6 +2,8 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
 import org.briarproject.bramble.api.contact.event.ContactStatusChangedEvent;
@@ -21,8 +23,10 @@ import org.briarproject.bramble.api.db.NoSuchContactException;
 import org.briarproject.bramble.api.db.NoSuchGroupException;
 import org.briarproject.bramble.api.db.NoSuchLocalAuthorException;
 import org.briarproject.bramble.api.db.NoSuchMessageException;
+import org.briarproject.bramble.api.db.NoSuchPendingContactException;
 import org.briarproject.bramble.api.db.NoSuchTransportException;
 import org.briarproject.bramble.api.db.NullableDbCallable;
+import org.briarproject.bramble.api.db.PendingContactExistsException;
 import org.briarproject.bramble.api.db.TaskAction;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.event.EventBus;
@@ -59,8 +63,11 @@ import org.briarproject.bramble.api.sync.event.MessageToRequestEvent;
 import org.briarproject.bramble.api.sync.event.MessagesAckedEvent;
 import org.briarproject.bramble.api.sync.event.MessagesSentEvent;
 import org.briarproject.bramble.api.sync.validation.MessageState;
-import org.briarproject.bramble.api.transport.KeySet;
+import org.briarproject.bramble.api.transport.HandshakeKeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
 import java.util.ArrayList;
@@ -253,6 +260,30 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		}
 	}
 
+	@Override
+	public HandshakeKeySetId addHandshakeKeys(Transaction transaction,
+			ContactId c, HandshakeKeys k) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsContact(txn, c))
+			throw new NoSuchContactException();
+		if (!db.containsTransport(txn, k.getTransportId()))
+			throw new NoSuchTransportException();
+		return db.addHandshakeKeys(txn, c, k);
+	}
+
+	@Override
+	public HandshakeKeySetId addHandshakeKeys(Transaction transaction,
+			PendingContactId p, HandshakeKeys k) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsPendingContact(txn, p))
+			throw new NoSuchPendingContactException();
+		if (!db.containsTransport(txn, k.getTransportId()))
+			throw new NoSuchTransportException();
+		return db.addHandshakeKeys(txn, p, k);
+	}
+
 	@Override
 	public void addLocalAuthor(Transaction transaction, LocalAuthor a)
 			throws DbException {
@@ -281,6 +312,16 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		db.mergeMessageMetadata(txn, m.getId(), meta);
 	}
 
+	@Override
+	public void addPendingContact(Transaction transaction, PendingContact p)
+			throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (db.containsPendingContact(txn, p.getId()))
+			throw new PendingContactExistsException();
+		db.addPendingContact(txn, p);
+	}
+
 	@Override
 	public void addTransport(Transaction transaction, TransportId t,
 			int maxLatency) throws DbException {
@@ -291,8 +332,8 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public KeySetId addTransportKeys(Transaction transaction, ContactId c,
+	public TransportKeySetId addTransportKeys(Transaction transaction,
-			TransportKeys k) throws DbException {
+			ContactId c, TransportKeys k) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
@@ -325,6 +366,13 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.containsLocalAuthor(txn, local);
 	}
 
+	@Override
+	public boolean containsPendingContact(Transaction transaction,
+			PendingContactId p) throws DbException {
+		T txn = unbox(transaction);
+		return db.containsPendingContact(txn, p);
+	}
+
 	@Override
 	public void deleteMessage(Transaction transaction, MessageId m)
 			throws DbException {
@@ -498,6 +546,15 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getGroupVisibility(txn, c, g);
 	}
 
+	@Override
+	public Collection<HandshakeKeySet> getHandshakeKeys(Transaction transaction,
+			TransportId t) throws DbException {
+		T txn = unbox(transaction);
+		if (!db.containsTransport(txn, t))
+			throw new NoSuchTransportException();
+		return db.getHandshakeKeys(txn, t);
+	}
+
 	@Override
 	public LocalAuthor getLocalAuthor(Transaction transaction, AuthorId a)
 			throws DbException {
@@ -655,6 +712,13 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getNextSendTime(txn, c);
 	}
 
+	@Override
+	public Collection<PendingContact> getPendingContacts(
+			Transaction transaction) throws DbException {
+		T txn = unbox(transaction);
+		return db.getPendingContacts(txn);
+	}
+
 	@Override
 	public Settings getSettings(Transaction transaction, String namespace)
 			throws DbException {
@@ -663,7 +727,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public Collection<KeySet> getTransportKeys(Transaction transaction,
+	public Collection<TransportKeySet> getTransportKeys(Transaction transaction,
 			TransportId t) throws DbException {
 		T txn = unbox(transaction);
 		if (!db.containsTransport(txn, t))
@@ -673,7 +737,17 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 
 	@Override
 	public void incrementStreamCounter(Transaction transaction, TransportId t,
-			KeySetId k) throws DbException {
+			HandshakeKeySetId k) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsTransport(txn, t))
+			throw new NoSuchTransportException();
+		db.incrementStreamCounter(txn, t, k);
+	}
+
+	@Override
+	public void incrementStreamCounter(Transaction transaction, TransportId t,
+			TransportKeySetId k) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsTransport(txn, t))
@@ -822,6 +896,16 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		transaction.attach(new GroupVisibilityUpdatedEvent(affected));
 	}
 
+	@Override
+	public void removeHandshakeKeys(Transaction transaction,
+			TransportId t, HandshakeKeySetId k) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsTransport(txn, t))
+			throw new NoSuchTransportException();
+		db.removeHandshakeKeys(txn, t, k);
+	}
+
 	@Override
 	public void removeLocalAuthor(Transaction transaction, AuthorId a)
 			throws DbException {
@@ -844,6 +928,16 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		db.removeMessage(txn, m);
 	}
 
+	@Override
+	public void removePendingContact(Transaction transaction,
+			PendingContactId p) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsPendingContact(txn, p))
+			throw new NoSuchPendingContactException();
+		db.removePendingContact(txn, p);
+	}
+
 	@Override
 	public void removeTransport(Transaction transaction, TransportId t)
 			throws DbException {
@@ -856,7 +950,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 
 	@Override
 	public void removeTransportKeys(Transaction transaction,
-			TransportId t, KeySetId k) throws DbException {
+			TransportId t, TransportKeySetId k) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsTransport(txn, t))
@@ -955,19 +1049,30 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public void setReorderingWindow(Transaction transaction, KeySetId k,
+	public void setReorderingWindow(Transaction transaction,
-			TransportId t, long rotationPeriod, long base, byte[] bitmap)
+			TransportKeySetId k, TransportId t, long timePeriod, long base,
-			throws DbException {
+			byte[] bitmap) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsTransport(txn, t))
 			throw new NoSuchTransportException();
-		db.setReorderingWindow(txn, k, t, rotationPeriod, base, bitmap);
+		db.setReorderingWindow(txn, k, t, timePeriod, base, bitmap);
+	}
+
+	@Override
+	public void setReorderingWindow(Transaction transaction,
+			HandshakeKeySetId k, TransportId t, long timePeriod, long base,
+			byte[] bitmap) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsTransport(txn, t))
+			throw new NoSuchTransportException();
+		db.setReorderingWindow(txn, k, t, timePeriod, base, bitmap);
 	}
 
 	@Override
 	public void setTransportKeysActive(Transaction transaction, TransportId t,
-			KeySetId k) throws DbException {
+			TransportKeySetId k) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsTransport(txn, t))
@@ -976,12 +1081,24 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public void updateTransportKeys(Transaction transaction,
+	public void updateHandshakeKeys(Transaction transaction,
-			Collection<KeySet> keys) throws DbException {
+			Collection<HandshakeKeySet> keys) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
-		for (KeySet ks : keys) {
+		for (HandshakeKeySet ks : keys) {
-			TransportId t = ks.getTransportKeys().getTransportId();
+			TransportId t = ks.getKeys().getTransportId();
+			if (db.containsTransport(txn, t))
+				db.updateHandshakeKeys(txn, ks);
+		}
+	}
+
+	@Override
+	public void updateTransportKeys(Transaction transaction,
+			Collection<TransportKeySet> keys) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		for (TransportKeySet ks : keys) {
+			TransportId t = ks.getKeys().getTransportId();
 			if (db.containsTransport(txn, t))
 				db.updateTransportKeys(txn, ks);
 		}

bramble-core/src/main/java/org/briarproject/bramble/db/JdbcDatabase.java

@@ -2,6 +2,9 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.contact.PendingContactState;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DataTooNewException;
 import org.briarproject.bramble.api.db.DataTooOldException;
@@ -26,10 +29,13 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.validation.MessageState;
 import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.transport.HandshakeKeySet;
+import org.briarproject.bramble.api.transport.HandshakeKeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
 import org.briarproject.bramble.api.transport.IncomingKeys;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
 import java.sql.Connection;
@@ -55,6 +61,7 @@ import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 
+import static java.sql.Types.BINARY;
 import static java.sql.Types.INTEGER;
 import static java.sql.Types.VARCHAR;
 import static java.util.logging.Level.INFO;
@@ -85,9 +92,9 @@ import static org.briarproject.bramble.util.LogUtils.now;
 abstract class JdbcDatabase implements Database<Connection> {
 
 	// Package access for testing
-	static final int CODE_SCHEMA_VERSION = 41;
+	static final int CODE_SCHEMA_VERSION = 42;
 
-	// Rotation period offsets for incoming transport keys
+	// Time period offsets for incoming transport keys
 	private static final int OFFSET_PREV = -1;
 	private static final int OFFSET_CURR = 0;
 	private static final int OFFSET_NEXT = 1;
@@ -248,7 +255,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			"CREATE TABLE outgoingKeys"
 					+ " (transportId _STRING NOT NULL,"
 					+ " keySetId _COUNTER,"
-					+ " rotationPeriod BIGINT NOT NULL,"
+					+ " timePeriod BIGINT NOT NULL,"
 					+ " contactId INT NOT NULL,"
 					+ " tagKey _SECRET NOT NULL,"
 					+ " headerKey _SECRET NOT NULL,"
@@ -267,8 +274,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			"CREATE TABLE incomingKeys"
 					+ " (transportId _STRING NOT NULL,"
 					+ " keySetId INT NOT NULL,"
-					+ " rotationPeriod BIGINT NOT NULL,"
+					+ " timePeriod BIGINT NOT NULL,"
-					+ " contactId INT NOT NULL,"
 					+ " tagKey _SECRET NOT NULL,"
 					+ " headerKey _SECRET NOT NULL,"
 					+ " base BIGINT NOT NULL,"
@@ -280,9 +286,57 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " ON DELETE CASCADE,"
 					+ " FOREIGN KEY (keySetId)"
 					+ " REFERENCES outgoingKeys (keySetId)"
+					+ " ON DELETE CASCADE)";
+
+	private static final String CREATE_PENDING_CONTACTS =
+			"CREATE TABLE pendingContacts"
+					+ " (pendingContactId _HASH NOT NULL,"
+					+ " publicKey _BINARY NOT NULL,"
+					+ " alias _STRING NOT NULL,"
+					+ " state INT NOT NULL,"
+					+ " timestamp BIGINT NOT NULL,"
+					+ " PRIMARY KEY (pendingContactId))";
+
+	private static final String CREATE_OUTGOING_HANDSHAKE_KEYS =
+			"CREATE TABLE outgoingHandshakeKeys"
+					+ " (transportId _STRING NOT NULL,"
+					+ " keySetId _COUNTER,"
+					+ " timePeriod BIGINT NOT NULL,"
+					+ " contactId INT," // Null if contact is pending
+					+ " pendingContactId _HASH," // Null if not pending
+					+ " rootKey _SECRET NOT NULL,"
+					+ " alice BOOLEAN NOT NULL,"
+					+ " tagKey _SECRET NOT NULL,"
+					+ " headerKey _SECRET NOT NULL,"
+					+ " stream BIGINT NOT NULL,"
+					+ " PRIMARY KEY (transportId, keySetId),"
+					+ " FOREIGN KEY (transportId)"
+					+ " REFERENCES transports (transportId)"
 					+ " ON DELETE CASCADE,"
+					+ " UNIQUE (keySetId),"
 					+ " FOREIGN KEY (contactId)"
 					+ " REFERENCES contacts (contactId)"
+					+ " ON DELETE CASCADE,"
+					+ " FOREIGN KEY (pendingContactId)"
+					+ " REFERENCES pendingContacts (pendingContactId)"
+					+ " ON DELETE CASCADE)";
+
+	private static final String CREATE_INCOMING_HANDSHAKE_KEYS =
+			"CREATE TABLE incomingHandshakeKeys"
+					+ " (transportId _STRING NOT NULL,"
+					+ " keySetId INT NOT NULL,"
+					+ " timePeriod BIGINT NOT NULL,"
+					+ " tagKey _SECRET NOT NULL,"
+					+ " headerKey _SECRET NOT NULL,"
+					+ " base BIGINT NOT NULL,"
+					+ " bitmap _BINARY NOT NULL,"
+					+ " periodOffset INT NOT NULL,"
+					+ " PRIMARY KEY (transportId, keySetId, periodOffset),"
+					+ " FOREIGN KEY (transportId)"
+					+ " REFERENCES transports (transportId)"
+					+ " ON DELETE CASCADE,"
+					+ " FOREIGN KEY (keySetId)"
+					+ " REFERENCES outgoingHandshakeKeys (keySetId)"
 					+ " ON DELETE CASCADE)";
 
 	private static final String INDEX_CONTACTS_BY_AUTHOR_ID =
@@ -428,7 +482,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 		return Arrays.asList(
 				new Migration38_39(),
 				new Migration39_40(),
-				new Migration40_41(dbTypes)
+				new Migration40_41(dbTypes),
+				new Migration41_42(dbTypes)
 		);
 	}
 
@@ -478,6 +533,11 @@ abstract class JdbcDatabase implements Database<Connection> {
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_TRANSPORTS));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_OUTGOING_KEYS));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_INCOMING_KEYS));
+			s.executeUpdate(dbTypes.replaceTypes(CREATE_PENDING_CONTACTS));
+			s.executeUpdate(dbTypes.replaceTypes(
+					CREATE_OUTGOING_HANDSHAKE_KEYS));
+			s.executeUpdate(dbTypes.replaceTypes(
+					CREATE_INCOMING_HANDSHAKE_KEYS));
 			s.close();
 		} catch (SQLException e) {
 			tryToClose(s, LOG, WARNING);
@@ -715,6 +775,103 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public HandshakeKeySetId addHandshakeKeys(Connection txn, ContactId c,
+			HandshakeKeys k) throws DbException {
+		return addHandshakeKeys(txn, c, null, k);
+	}
+
+	@Override
+	public HandshakeKeySetId addHandshakeKeys(Connection txn,
+			PendingContactId p, HandshakeKeys k) throws DbException {
+		return addHandshakeKeys(txn, null, p, k);
+	}
+
+	private HandshakeKeySetId addHandshakeKeys(Connection txn,
+			@Nullable ContactId c, @Nullable PendingContactId p,
+			HandshakeKeys k) throws DbException {
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			// Store the outgoing keys
+			String sql = "INSERT INTO outgoingHandshakeKeys (contactId,"
+					+ " pendingContactId, transportId, rootKey, alice,"
+					+ " timePeriod, tagKey, headerKey, stream)"
+					+ " VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)";
+			ps = txn.prepareStatement(sql);
+			if (c == null) ps.setNull(1, INTEGER);
+			else ps.setInt(1, c.getInt());
+			if (p == null) ps.setNull(2, BINARY);
+			else ps.setBytes(2, p.getBytes());
+			ps.setString(3, k.getTransportId().getString());
+			ps.setBytes(4, k.getRootKey().getBytes());
+			ps.setBoolean(5, k.isAlice());
+			OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
+			ps.setLong(6, outCurr.getTimePeriod());
+			ps.setBytes(7, outCurr.getTagKey().getBytes());
+			ps.setBytes(8, outCurr.getHeaderKey().getBytes());
+			ps.setLong(9, outCurr.getStreamCounter());
+			int affected = ps.executeUpdate();
+			if (affected != 1) throw new DbStateException();
+			ps.close();
+			// Get the new (highest) key set ID
+			sql = "SELECT keySetId FROM outgoingHandshakeKeys"
+					+ " ORDER BY keySetId DESC LIMIT 1";
+			ps = txn.prepareStatement(sql);
+			rs = ps.executeQuery();
+			if (!rs.next()) throw new DbStateException();
+			HandshakeKeySetId keySetId = new HandshakeKeySetId(rs.getInt(1));
+			if (rs.next()) throw new DbStateException();
+			rs.close();
+			ps.close();
+			// Store the incoming keys
+			sql = "INSERT INTO incomingHandshakeKeys (keySetId, transportId,"
+					+ " timePeriod, tagKey, headerKey, base, bitmap,"
+					+ " periodOffset)"
+					+ " VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
+			ps = txn.prepareStatement(sql);
+			ps.setInt(1, keySetId.getInt());
+			ps.setString(2, k.getTransportId().getString());
+			// Previous time period
+			IncomingKeys inPrev = k.getPreviousIncomingKeys();
+			ps.setLong(3, inPrev.getTimePeriod());
+			ps.setBytes(4, inPrev.getTagKey().getBytes());
+			ps.setBytes(5, inPrev.getHeaderKey().getBytes());
+			ps.setLong(6, inPrev.getWindowBase());
+			ps.setBytes(7, inPrev.getWindowBitmap());
+			ps.setInt(8, OFFSET_PREV);
+			ps.addBatch();
+			// Current time period
+			IncomingKeys inCurr = k.getCurrentIncomingKeys();
+			ps.setLong(3, inCurr.getTimePeriod());
+			ps.setBytes(4, inCurr.getTagKey().getBytes());
+			ps.setBytes(5, inCurr.getHeaderKey().getBytes());
+			ps.setLong(6, inCurr.getWindowBase());
+			ps.setBytes(7, inCurr.getWindowBitmap());
+			ps.setInt(8, OFFSET_CURR);
+			ps.addBatch();
+			// Next time period
+			IncomingKeys inNext = k.getNextIncomingKeys();
+			ps.setLong(3, inNext.getTimePeriod());
+			ps.setBytes(4, inNext.getTagKey().getBytes());
+			ps.setBytes(5, inNext.getHeaderKey().getBytes());
+			ps.setLong(6, inNext.getWindowBase());
+			ps.setBytes(7, inNext.getWindowBitmap());
+			ps.setInt(8, OFFSET_NEXT);
+			ps.addBatch();
+			int[] batchAffected = ps.executeBatch();
+			if (batchAffected.length != 3) throw new DbStateException();
+			for (int rows : batchAffected)
+				if (rows != 1) throw new DbStateException();
+			ps.close();
+			return keySetId;
+		} catch (SQLException e) {
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public void addLocalAuthor(Connection txn, LocalAuthor a)
 			throws DbException {
@@ -895,6 +1052,29 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public void addPendingContact(Connection txn, PendingContact p)
+			throws DbException {
+		PreparedStatement ps = null;
+		try {
+			String sql = "INSERT INTO pendingContacts (pendingContactId,"
+					+ " publicKey, alias, state, timestamp)"
+					+ " VALUES (?, ?, ?, ?, ?)";
+			ps = txn.prepareStatement(sql);
+			ps.setBytes(1, p.getId().getBytes());
+			ps.setBytes(2, p.getPublicKey());
+			ps.setString(3, p.getAlias());
+			ps.setInt(4, p.getState().getValue());
+			ps.setLong(5, p.getTimestamp());
+			int affected = ps.executeUpdate();
+			if (affected != 1) throw new DbStateException();
+			ps.close();
+		} catch (SQLException e) {
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public void addTransport(Connection txn, TransportId t, int maxLatency)
 			throws DbException {
@@ -915,20 +1095,20 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public KeySetId addTransportKeys(Connection txn, ContactId c,
+	public TransportKeySetId addTransportKeys(Connection txn, ContactId c,
 			TransportKeys k) throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
 			// Store the outgoing keys
 			String sql = "INSERT INTO outgoingKeys (contactId, transportId,"
-					+ " rotationPeriod, tagKey, headerKey, stream, active)"
+					+ " timePeriod, tagKey, headerKey, stream, active)"
 					+ " VALUES (?, ?, ?, ?, ?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
 			ps.setString(2, k.getTransportId().getString());
 			OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
-			ps.setLong(3, outCurr.getRotationPeriod());
+			ps.setLong(3, outCurr.getTimePeriod());
 			ps.setBytes(4, outCurr.getTagKey().getBytes());
 			ps.setBytes(5, outCurr.getHeaderKey().getBytes());
 			ps.setLong(6, outCurr.getStreamCounter());
@@ -942,45 +1122,44 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			rs = ps.executeQuery();
 			if (!rs.next()) throw new DbStateException();
-			KeySetId keySetId = new KeySetId(rs.getInt(1));
+			TransportKeySetId keySetId = new TransportKeySetId(rs.getInt(1));
 			if (rs.next()) throw new DbStateException();
 			rs.close();
 			ps.close();
 			// Store the incoming keys
-			sql = "INSERT INTO incomingKeys (keySetId, contactId, transportId,"
+			sql = "INSERT INTO incomingKeys (keySetId, transportId,"
-					+ " rotationPeriod, tagKey, headerKey, base, bitmap,"
+					+ " timePeriod, tagKey, headerKey, base, bitmap,"
 					+ " periodOffset)"
-					+ " VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)";
+					+ " VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, keySetId.getInt());
-			ps.setInt(2, c.getInt());
+			ps.setString(2, k.getTransportId().getString());
-			ps.setString(3, k.getTransportId().getString());
+			// Previous time period
-			// Previous rotation period
 			IncomingKeys inPrev = k.getPreviousIncomingKeys();
-			ps.setLong(4, inPrev.getRotationPeriod());
+			ps.setLong(3, inPrev.getTimePeriod());
-			ps.setBytes(5, inPrev.getTagKey().getBytes());
+			ps.setBytes(4, inPrev.getTagKey().getBytes());
-			ps.setBytes(6, inPrev.getHeaderKey().getBytes());
+			ps.setBytes(5, inPrev.getHeaderKey().getBytes());
-			ps.setLong(7, inPrev.getWindowBase());
+			ps.setLong(6, inPrev.getWindowBase());
-			ps.setBytes(8, inPrev.getWindowBitmap());
+			ps.setBytes(7, inPrev.getWindowBitmap());
-			ps.setInt(9, OFFSET_PREV);
+			ps.setInt(8, OFFSET_PREV);
 			ps.addBatch();
-			// Current rotation period
+			// Current time period
 			IncomingKeys inCurr = k.getCurrentIncomingKeys();
-			ps.setLong(4, inCurr.getRotationPeriod());
+			ps.setLong(3, inCurr.getTimePeriod());
-			ps.setBytes(5, inCurr.getTagKey().getBytes());
+			ps.setBytes(4, inCurr.getTagKey().getBytes());
-			ps.setBytes(6, inCurr.getHeaderKey().getBytes());
+			ps.setBytes(5, inCurr.getHeaderKey().getBytes());
-			ps.setLong(7, inCurr.getWindowBase());
+			ps.setLong(6, inCurr.getWindowBase());
-			ps.setBytes(8, inCurr.getWindowBitmap());
+			ps.setBytes(7, inCurr.getWindowBitmap());
-			ps.setInt(9, OFFSET_CURR);
+			ps.setInt(8, OFFSET_CURR);
 			ps.addBatch();
-			// Next rotation period
+			// Next time period
 			IncomingKeys inNext = k.getNextIncomingKeys();
-			ps.setLong(4, inNext.getRotationPeriod());
+			ps.setLong(3, inNext.getTimePeriod());
-			ps.setBytes(5, inNext.getTagKey().getBytes());
+			ps.setBytes(4, inNext.getTagKey().getBytes());
-			ps.setBytes(6, inNext.getHeaderKey().getBytes());
+			ps.setBytes(5, inNext.getHeaderKey().getBytes());
-			ps.setLong(7, inNext.getWindowBase());
+			ps.setLong(6, inNext.getWindowBase());
-			ps.setBytes(8, inNext.getWindowBitmap());
+			ps.setBytes(7, inNext.getWindowBitmap());
-			ps.setInt(9, OFFSET_NEXT);
+			ps.setInt(8, OFFSET_NEXT);
 			ps.addBatch();
 			int[] batchAffected = ps.executeBatch();
 			if (batchAffected.length != 3) throw new DbStateException();
@@ -1107,6 +1286,29 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public boolean containsPendingContact(Connection txn, PendingContactId p)
+			throws DbException {
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			String sql = "SELECT NULL FROM pendingContacts"
+					+ " WHERE pendingContactId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setBytes(1, p.getBytes());
+			rs = ps.executeQuery();
+			boolean found = rs.next();
+			if (rs.next()) throw new DbStateException();
+			rs.close();
+			ps.close();
+			return found;
+		} catch (SQLException e) {
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public boolean containsTransport(Connection txn, TransportId t)
 			throws DbException {
@@ -1256,14 +1458,14 @@ abstract class JdbcDatabase implements Database<Connection> {
 	@Override
 	public Collection<Contact> getContacts(Connection txn)
 			throws DbException {
-		PreparedStatement ps = null;
+		Statement s = null;
 		ResultSet rs = null;
 		try {
 			String sql = "SELECT contactId, authorId, formatVersion, name,"
 					+ " alias, publicKey, localAuthorId, verified, active"
 					+ " FROM contacts";
-			ps = txn.prepareStatement(sql);
+			s = txn.createStatement();
-			rs = ps.executeQuery();
+			rs = s.executeQuery(sql);
 			List<Contact> contacts = new ArrayList<>();
 			while (rs.next()) {
 				ContactId contactId = new ContactId(rs.getInt(1));
@@ -1281,11 +1483,11 @@ abstract class JdbcDatabase implements Database<Connection> {
 						alias, verified, active));
 			}
 			rs.close();
-			ps.close();
+			s.close();
 			return contacts;
 		} catch (SQLException e) {
 			tryToClose(rs, LOG, WARNING);
-			tryToClose(ps, LOG, WARNING);
+			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);
 		}
 	}
@@ -1485,6 +1687,86 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public Collection<HandshakeKeySet> getHandshakeKeys(Connection txn,
+			TransportId t) throws DbException {
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			// Retrieve the incoming keys
+			String sql = "SELECT timePeriod, tagKey, headerKey, base, bitmap"
+					+ " FROM incomingHandshakeKeys"
+					+ " WHERE transportId = ?"
+					+ " ORDER BY keySetId, periodOffset";
+			ps = txn.prepareStatement(sql);
+			ps.setString(1, t.getString());
+			rs = ps.executeQuery();
+			List<IncomingKeys> inKeys = new ArrayList<>();
+			while (rs.next()) {
+				long timePeriod = rs.getLong(1);
+				SecretKey tagKey = new SecretKey(rs.getBytes(2));
+				SecretKey headerKey = new SecretKey(rs.getBytes(3));
+				long windowBase = rs.getLong(4);
+				byte[] windowBitmap = rs.getBytes(5);
+				inKeys.add(new IncomingKeys(tagKey, headerKey, timePeriod,
+						windowBase, windowBitmap));
+			}
+			rs.close();
+			ps.close();
+			// Retrieve the outgoing keys in the same order
+			sql = "SELECT keySetId, contactId, pendingContactId, timePeriod,"
+					+ " tagKey, headerKey, rootKey, alice, stream"
+					+ " FROM outgoingHandshakeKeys"
+					+ " WHERE transportId = ?"
+					+ " ORDER BY keySetId";
+			ps = txn.prepareStatement(sql);
+			ps.setString(1, t.getString());
+			rs = ps.executeQuery();
+			Collection<HandshakeKeySet> keys = new ArrayList<>();
+			for (int i = 0; rs.next(); i++) {
+				// There should be three times as many incoming keys
+				if (inKeys.size() < (i + 1) * 3) throw new DbStateException();
+				HandshakeKeySetId keySetId =
+						new HandshakeKeySetId(rs.getInt(1));
+				ContactId contactId = null;
+				int cId = rs.getInt(2);
+				if (!rs.wasNull()) contactId = new ContactId(cId);
+				PendingContactId pendingContactId = null;
+				byte[] pId = rs.getBytes(3);
+				if (!rs.wasNull()) pendingContactId = new PendingContactId(pId);
+				long timePeriod = rs.getLong(4);
+				SecretKey tagKey = new SecretKey(rs.getBytes(5));
+				SecretKey headerKey = new SecretKey(rs.getBytes(6));
+				SecretKey rootKey = new SecretKey(rs.getBytes(7));
+				boolean alice = rs.getBoolean(8);
+				long streamCounter = rs.getLong(9);
+				OutgoingKeys outCurr = new OutgoingKeys(tagKey, headerKey,
+						timePeriod, streamCounter, true);
+				IncomingKeys inPrev = inKeys.get(i * 3);
+				IncomingKeys inCurr = inKeys.get(i * 3 + 1);
+				IncomingKeys inNext = inKeys.get(i * 3 + 2);
+				HandshakeKeys handshakeKeys = new HandshakeKeys(t, inPrev,
+						inCurr, inNext, outCurr, rootKey, alice);
+				if (contactId == null) {
+					if (pendingContactId == null) throw new DbStateException();
+					keys.add(new HandshakeKeySet(keySetId, pendingContactId,
+							handshakeKeys));
+				} else {
+					if (pendingContactId != null) throw new DbStateException();
+					keys.add(new HandshakeKeySet(keySetId, contactId,
+							handshakeKeys));
+				}
+			}
+			rs.close();
+			ps.close();
+			return keys;
+		} catch (SQLException e) {
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public Collection<LocalAuthor> getLocalAuthors(Connection txn)
 			throws DbException {
@@ -2086,6 +2368,38 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public Collection<PendingContact> getPendingContacts(Connection txn)
+			throws DbException {
+		Statement s = null;
+		ResultSet rs = null;
+		try {
+			String sql = "SELECT pendingContactId, publicKey, alias, state,"
+					+ " timestamp"
+					+ " FROM pendingContacts";
+			s = txn.createStatement();
+			rs = s.executeQuery(sql);
+			List<PendingContact> pendingContacts = new ArrayList<>();
+			while (rs.next()) {
+				PendingContactId id = new PendingContactId(rs.getBytes(1));
+				byte[] publicKey = rs.getBytes(2);
+				String alias = rs.getString(3);
+				PendingContactState state =
+						PendingContactState.fromValue(rs.getInt(4));
+				long timestamp = rs.getLong(5);
+				pendingContacts.add(new PendingContact(id, publicKey, alias,
+						state, timestamp));
+			}
+			rs.close();
+			s.close();
+			return pendingContacts;
+		} catch (SQLException e) {
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public Collection<MessageId> getRequestedMessagesToSend(Connection txn,
 			ContactId c, int maxLength, int maxLatency) throws DbException {
@@ -2149,14 +2463,13 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public Collection<KeySet> getTransportKeys(Connection txn, TransportId t)
+	public Collection<TransportKeySet> getTransportKeys(Connection txn,
-			throws DbException {
+			TransportId t) throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
 			// Retrieve the incoming keys
-			String sql = "SELECT rotationPeriod, tagKey, headerKey,"
+			String sql = "SELECT timePeriod, tagKey, headerKey, base, bitmap"
-					+ " base, bitmap"
 					+ " FROM incomingKeys"
 					+ " WHERE transportId = ?"
 					+ " ORDER BY keySetId, periodOffset";
@@ -2165,18 +2478,18 @@ abstract class JdbcDatabase implements Database<Connection> {
 			rs = ps.executeQuery();
 			List<IncomingKeys> inKeys = new ArrayList<>();
 			while (rs.next()) {
-				long rotationPeriod = rs.getLong(1);
+				long timePeriod = rs.getLong(1);
 				SecretKey tagKey = new SecretKey(rs.getBytes(2));
 				SecretKey headerKey = new SecretKey(rs.getBytes(3));
 				long windowBase = rs.getLong(4);
 				byte[] windowBitmap = rs.getBytes(5);
-				inKeys.add(new IncomingKeys(tagKey, headerKey, rotationPeriod,
+				inKeys.add(new IncomingKeys(tagKey, headerKey, timePeriod,
 						windowBase, windowBitmap));
 			}
 			rs.close();
 			ps.close();
 			// Retrieve the outgoing keys in the same order
-			sql = "SELECT keySetId, contactId, rotationPeriod,"
+			sql = "SELECT keySetId, contactId, timePeriod,"
 					+ " tagKey, headerKey, stream, active"
 					+ " FROM outgoingKeys"
 					+ " WHERE transportId = ?"
@@ -2184,25 +2497,27 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setString(1, t.getString());
 			rs = ps.executeQuery();
-			Collection<KeySet> keys = new ArrayList<>();
+			Collection<TransportKeySet> keys = new ArrayList<>();
 			for (int i = 0; rs.next(); i++) {
 				// There should be three times as many incoming keys
 				if (inKeys.size() < (i + 1) * 3) throw new DbStateException();
-				KeySetId keySetId = new KeySetId(rs.getInt(1));
+				TransportKeySetId keySetId =
+						new TransportKeySetId(rs.getInt(1));
 				ContactId contactId = new ContactId(rs.getInt(2));
-				long rotationPeriod = rs.getLong(3);
+				long timePeriod = rs.getLong(3);
 				SecretKey tagKey = new SecretKey(rs.getBytes(4));
 				SecretKey headerKey = new SecretKey(rs.getBytes(5));
 				long streamCounter = rs.getLong(6);
 				boolean active = rs.getBoolean(7);
 				OutgoingKeys outCurr = new OutgoingKeys(tagKey, headerKey,
-						rotationPeriod, streamCounter, active);
+						timePeriod, streamCounter, active);
 				IncomingKeys inPrev = inKeys.get(i * 3);
 				IncomingKeys inCurr = inKeys.get(i * 3 + 1);
 				IncomingKeys inNext = inKeys.get(i * 3 + 2);
 				TransportKeys transportKeys = new TransportKeys(t, inPrev,
 						inCurr, inNext, outCurr);
-				keys.add(new KeySet(keySetId, contactId, transportKeys));
+				keys.add(new TransportKeySet(keySetId, contactId,
+						transportKeys));
 			}
 			rs.close();
 			ps.close();
@@ -2216,7 +2531,26 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	@Override
 	public void incrementStreamCounter(Connection txn, TransportId t,
-			KeySetId k) throws DbException {
+			HandshakeKeySetId k) throws DbException {
+		PreparedStatement ps = null;
+		try {
+			String sql = "UPDATE outgoingHandshakeKeys SET stream = stream + 1"
+					+ " WHERE transportId = ? AND keySetId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setString(1, t.getString());
+			ps.setInt(2, k.getInt());
+			int affected = ps.executeUpdate();
+			if (affected != 1) throw new DbStateException();
+			ps.close();
+		} catch (SQLException e) {
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
+	@Override
+	public void incrementStreamCounter(Connection txn, TransportId t,
+			TransportKeySetId k) throws DbException {
 		PreparedStatement ps = null;
 		try {
 			String sql = "UPDATE outgoingKeys SET stream = stream + 1"
@@ -2594,6 +2928,27 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public void removeHandshakeKeys(Connection txn, TransportId t,
+			HandshakeKeySetId k) throws DbException {
+		PreparedStatement ps = null;
+		try {
+			// Delete any existing outgoing keys - this will also remove any
+			// incoming keys with the same key set ID
+			String sql = "DELETE FROM outgoingHandshakeKeys"
+					+ " WHERE transportId = ? AND keySetId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setString(1, t.getString());
+			ps.setInt(2, k.getInt());
+			int affected = ps.executeUpdate();
+			if (affected < 0) throw new DbStateException();
+			ps.close();
+		} catch (SQLException e) {
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public void removeLocalAuthor(Connection txn, AuthorId a)
 			throws DbException {
@@ -2671,6 +3026,24 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public void removePendingContact(Connection txn, PendingContactId p)
+			throws DbException {
+		PreparedStatement ps = null;
+		try {
+			String sql = "DELETE FROM pendingContacts"
+					+ " WHERE pendingContactId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setBytes(1, p.getBytes());
+			int affected = ps.executeUpdate();
+			if (affected != 1) throw new DbStateException();
+			ps.close();
+		} catch (SQLException e) {
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public void removeTransport(Connection txn, TransportId t)
 			throws DbException {
@@ -2689,8 +3062,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public void removeTransportKeys(Connection txn, TransportId t, KeySetId k)
+	public void removeTransportKeys(Connection txn, TransportId t,
-			throws DbException {
+			TransportKeySetId k) throws DbException {
 		PreparedStatement ps = null;
 		try {
 			// Delete any existing outgoing keys - this will also remove any
@@ -2893,19 +3266,63 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public void setReorderingWindow(Connection txn, KeySetId k, TransportId t,
+	public void setPendingContactState(Connection txn, PendingContactId p,
-			long rotationPeriod, long base, byte[] bitmap) throws DbException {
+			PendingContactState state) throws DbException {
+		PreparedStatement ps = null;
+		try {
+			String sql = "UPDATE pendingContacts SET state = ?"
+					+ " WHERE pendingContactId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setInt(1, state.getValue());
+			ps.setBytes(2, p.getBytes());
+			int affected = ps.executeUpdate();
+			if (affected != 1) throw new DbStateException();
+			ps.close();
+		} catch (SQLException e) {
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
+	@Override
+	public void setReorderingWindow(Connection txn, TransportKeySetId k,
+			TransportId t, long timePeriod, long base, byte[] bitmap)
+			throws DbException {
 		PreparedStatement ps = null;
 		try {
 			String sql = "UPDATE incomingKeys SET base = ?, bitmap = ?"
 					+ " WHERE transportId = ? AND keySetId = ?"
-					+ " AND rotationPeriod = ?";
+					+ " AND timePeriod = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setLong(1, base);
 			ps.setBytes(2, bitmap);
 			ps.setString(3, t.getString());
 			ps.setInt(4, k.getInt());
-			ps.setLong(5, rotationPeriod);
+			ps.setLong(5, timePeriod);
+			int affected = ps.executeUpdate();
+			if (affected < 0 || affected > 1) throw new DbStateException();
+			ps.close();
+		} catch (SQLException e) {
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
+	@Override
+	public void setReorderingWindow(Connection txn, HandshakeKeySetId k,
+			TransportId t, long timePeriod, long base, byte[] bitmap)
+			throws DbException {
+		PreparedStatement ps = null;
+		try {
+			String sql = "UPDATE incomingHandshakeKeys SET base = ?, bitmap = ?"
+					+ " WHERE transportId = ? AND keySetId = ?"
+					+ " AND timePeriod = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setLong(1, base);
+			ps.setBytes(2, bitmap);
+			ps.setString(3, t.getString());
+			ps.setInt(4, k.getInt());
+			ps.setLong(5, timePeriod);
 			int affected = ps.executeUpdate();
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
@@ -2917,7 +3334,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	@Override
 	public void setTransportKeysActive(Connection txn, TransportId t,
-			KeySetId k) throws DbException {
+			TransportKeySetId k) throws DbException {
 		PreparedStatement ps = null;
 		try {
 			String sql = "UPDATE outgoingKeys SET active = true"
@@ -2972,18 +3389,18 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public void updateTransportKeys(Connection txn, KeySet ks)
+	public void updateTransportKeys(Connection txn, TransportKeySet ks)
 			throws DbException {
 		PreparedStatement ps = null;
 		try {
 			// Update the outgoing keys
-			String sql = "UPDATE outgoingKeys SET rotationPeriod = ?,"
+			String sql = "UPDATE outgoingKeys SET timePeriod = ?,"
 					+ " tagKey = ?, headerKey = ?, stream = ?"
 					+ " WHERE transportId = ? AND keySetId = ?";
 			ps = txn.prepareStatement(sql);
-			TransportKeys k = ks.getTransportKeys();
+			TransportKeys k = ks.getKeys();
 			OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
-			ps.setLong(1, outCurr.getRotationPeriod());
+			ps.setLong(1, outCurr.getTimePeriod());
 			ps.setBytes(2, outCurr.getTagKey().getBytes());
 			ps.setBytes(3, outCurr.getHeaderKey().getBytes());
 			ps.setLong(4, outCurr.getStreamCounter());
@@ -2993,34 +3410,101 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
 			// Update the incoming keys
-			sql = "UPDATE incomingKeys SET rotationPeriod = ?,"
+			sql = "UPDATE incomingKeys SET timePeriod = ?,"
 					+ " tagKey = ?, headerKey = ?, base = ?, bitmap = ?"
 					+ " WHERE transportId = ? AND keySetId = ?"
 					+ " AND periodOffset = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setString(6, k.getTransportId().getString());
 			ps.setInt(7, ks.getKeySetId().getInt());
-			// Previous rotation period
+			// Previous time period
 			IncomingKeys inPrev = k.getPreviousIncomingKeys();
-			ps.setLong(1, inPrev.getRotationPeriod());
+			ps.setLong(1, inPrev.getTimePeriod());
 			ps.setBytes(2, inPrev.getTagKey().getBytes());
 			ps.setBytes(3, inPrev.getHeaderKey().getBytes());
 			ps.setLong(4, inPrev.getWindowBase());
 			ps.setBytes(5, inPrev.getWindowBitmap());
 			ps.setInt(8, OFFSET_PREV);
 			ps.addBatch();
-			// Current rotation period
+			// Current time period
 			IncomingKeys inCurr = k.getCurrentIncomingKeys();
-			ps.setLong(1, inCurr.getRotationPeriod());
+			ps.setLong(1, inCurr.getTimePeriod());
 			ps.setBytes(2, inCurr.getTagKey().getBytes());
 			ps.setBytes(3, inCurr.getHeaderKey().getBytes());
 			ps.setLong(4, inCurr.getWindowBase());
 			ps.setBytes(5, inCurr.getWindowBitmap());
 			ps.setInt(8, OFFSET_CURR);
 			ps.addBatch();
-			// Next rotation period
+			// Next time period
 			IncomingKeys inNext = k.getNextIncomingKeys();
-			ps.setLong(1, inNext.getRotationPeriod());
+			ps.setLong(1, inNext.getTimePeriod());
+			ps.setBytes(2, inNext.getTagKey().getBytes());
+			ps.setBytes(3, inNext.getHeaderKey().getBytes());
+			ps.setLong(4, inNext.getWindowBase());
+			ps.setBytes(5, inNext.getWindowBitmap());
+			ps.setInt(8, OFFSET_NEXT);
+			ps.addBatch();
+			int[] batchAffected = ps.executeBatch();
+			if (batchAffected.length != 3) throw new DbStateException();
+			for (int rows : batchAffected)
+				if (rows < 0 || rows > 1) throw new DbStateException();
+			ps.close();
+		} catch (SQLException e) {
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
+	@Override
+	public void updateHandshakeKeys(Connection txn, HandshakeKeySet ks)
+			throws DbException {
+		PreparedStatement ps = null;
+		try {
+			// Update the outgoing keys
+			String sql = "UPDATE outgoingHandshakeKeys SET timePeriod = ?,"
+					+ " tagKey = ?, headerKey = ?, stream = ?"
+					+ " WHERE transportId = ? AND keySetId = ?";
+			ps = txn.prepareStatement(sql);
+			HandshakeKeys k = ks.getKeys();
+			OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
+			ps.setLong(1, outCurr.getTimePeriod());
+			ps.setBytes(2, outCurr.getTagKey().getBytes());
+			ps.setBytes(3, outCurr.getHeaderKey().getBytes());
+			ps.setLong(4, outCurr.getStreamCounter());
+			ps.setString(5, k.getTransportId().getString());
+			ps.setInt(6, ks.getKeySetId().getInt());
+			int affected = ps.executeUpdate();
+			if (affected < 0 || affected > 1) throw new DbStateException();
+			ps.close();
+			// Update the incoming keys
+			sql = "UPDATE incomingHandshakeKeys SET timePeriod = ?,"
+					+ " tagKey = ?, headerKey = ?, base = ?, bitmap = ?"
+					+ " WHERE transportId = ? AND keySetId = ?"
+					+ " AND periodOffset = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setString(6, k.getTransportId().getString());
+			ps.setInt(7, ks.getKeySetId().getInt());
+			// Previous time period
+			IncomingKeys inPrev = k.getPreviousIncomingKeys();
+			ps.setLong(1, inPrev.getTimePeriod());
+			ps.setBytes(2, inPrev.getTagKey().getBytes());
+			ps.setBytes(3, inPrev.getHeaderKey().getBytes());
+			ps.setLong(4, inPrev.getWindowBase());
+			ps.setBytes(5, inPrev.getWindowBitmap());
+			ps.setInt(8, OFFSET_PREV);
+			ps.addBatch();
+			// Current time period
+			IncomingKeys inCurr = k.getCurrentIncomingKeys();
+			ps.setLong(1, inCurr.getTimePeriod());
+			ps.setBytes(2, inCurr.getTagKey().getBytes());
+			ps.setBytes(3, inCurr.getHeaderKey().getBytes());
+			ps.setLong(4, inCurr.getWindowBase());
+			ps.setBytes(5, inCurr.getWindowBitmap());
+			ps.setInt(8, OFFSET_CURR);
+			ps.addBatch();
+			// Next time period
+			IncomingKeys inNext = k.getNextIncomingKeys();
+			ps.setLong(1, inNext.getTimePeriod());
 			ps.setBytes(2, inNext.getTagKey().getBytes());
 			ps.setBytes(3, inNext.getHeaderKey().getBytes());
 			ps.setLong(4, inNext.getWindowBase());

bramble-core/src/main/java/org/briarproject/bramble/db/Migration40_41.java

@@ -17,7 +17,7 @@ class Migration40_41 implements Migration<Connection> {
 
 	private final DatabaseTypes dbTypes;
 
-	public Migration40_41(DatabaseTypes databaseTypes) {
+	Migration40_41(DatabaseTypes databaseTypes) {
 		this.dbTypes = databaseTypes;
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/db/Migration41_42.java

@@ -0,0 +1,97 @@
+package org.briarproject.bramble.db;
+
+import org.briarproject.bramble.api.db.DbException;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
+
+class Migration41_42 implements Migration<Connection> {
+
+	private static final Logger LOG = getLogger(Migration41_42.class.getName());
+
+	private final DatabaseTypes dbTypes;
+
+	Migration41_42(DatabaseTypes dbTypes) {
+		this.dbTypes = dbTypes;
+	}
+
+	@Override
+	public int getStartVersion() {
+		return 41;
+	}
+
+	@Override
+	public int getEndVersion() {
+		return 42;
+	}
+
+	@Override
+	public void migrate(Connection txn) throws DbException {
+		Statement s = null;
+		try {
+			s = txn.createStatement();
+			s.execute("ALTER TABLE outgoingKeys"
+					+ " ALTER COLUMN rotationPeriod"
+					+ " RENAME TO timePeriod");
+			s.execute("ALTER TABLE incomingKeys"
+					+ " ALTER COLUMN rotationPeriod"
+					+ " RENAME TO timePeriod");
+			s.execute("ALTER TABLE incomingKeys"
+					+ " DROP COLUMN contactId");
+			s.execute(dbTypes.replaceTypes("CREATE TABLE pendingContacts"
+					+ " (pendingContactId _HASH NOT NULL,"
+					+ " publicKey _BINARY NOT NULL,"
+					+ " alias _STRING NOT NULL,"
+					+ " state INT NOT NULL,"
+					+ " timestamp BIGINT NOT NULL,"
+					+ " PRIMARY KEY (pendingContactId))"));
+			s.execute(dbTypes.replaceTypes("CREATE TABLE outgoingHandshakeKeys"
+					+ " (transportId _STRING NOT NULL,"
+					+ " keySetId _COUNTER,"
+					+ " timePeriod BIGINT NOT NULL,"
+					+ " contactId INT," // Null if contact is pending
+					+ " pendingContactId _HASH," // Null if not pending
+					+ " rootKey _SECRET NOT NULL,"
+					+ " alice BOOLEAN NOT NULL,"
+					+ " tagKey _SECRET NOT NULL,"
+					+ " headerKey _SECRET NOT NULL,"
+					+ " stream BIGINT NOT NULL,"
+					+ " PRIMARY KEY (transportId, keySetId),"
+					+ " FOREIGN KEY (transportId)"
+					+ " REFERENCES transports (transportId)"
+					+ " ON DELETE CASCADE,"
+					+ " UNIQUE (keySetId),"
+					+ " FOREIGN KEY (contactId)"
+					+ " REFERENCES contacts (contactId)"
+					+ " ON DELETE CASCADE,"
+					+ " FOREIGN KEY (pendingContactId)"
+					+ " REFERENCES pendingContacts (pendingContactId)"
+					+ " ON DELETE CASCADE)"));
+			s.execute(dbTypes.replaceTypes("CREATE TABLE incomingHandshakeKeys"
+					+ " (transportId _STRING NOT NULL,"
+					+ " keySetId INT NOT NULL,"
+					+ " timePeriod BIGINT NOT NULL,"
+					+ " tagKey _SECRET NOT NULL,"
+					+ " headerKey _SECRET NOT NULL,"
+					+ " base BIGINT NOT NULL,"
+					+ " bitmap _BINARY NOT NULL,"
+					+ " periodOffset INT NOT NULL,"
+					+ " PRIMARY KEY (transportId, keySetId, periodOffset),"
+					+ " FOREIGN KEY (transportId)"
+					+ " REFERENCES transports (transportId)"
+					+ " ON DELETE CASCADE,"
+					+ " FOREIGN KEY (keySetId)"
+					+ " REFERENCES outgoingHandshakeKeys (keySetId)"
+					+ " ON DELETE CASCADE)"));
+		} catch (SQLException e) {
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementProtocol.java

@@ -14,7 +14,7 @@ import java.io.IOException;
 import java.security.GeneralSecurityException;
 import java.util.Arrays;
 
-import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.MASTER_SECRET_LABEL;
+import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.MASTER_KEY_LABEL;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.PROTOCOL_VERSION;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.SHARED_SECRET_LABEL;
 
@@ -90,7 +90,7 @@ class KeyAgreementProtocol {
 	/**
 	 * Perform the BQP protocol.
 	 *
-	 * @return the negotiated master secret.
+	 * @return the negotiated master key.
 	 * @throws AbortException when the protocol may have been tampered with.
 	 * @throws IOException for all other other connection errors.
 	 */
@@ -115,7 +115,7 @@ class KeyAgreementProtocol {
 				receiveConfirm(s, theirPublicKey);
 				sendConfirm(s, theirPublicKey);
 			}
-			return crypto.deriveKey(MASTER_SECRET_LABEL, s);
+			return crypto.deriveKey(MASTER_KEY_LABEL, s);
 		} catch (AbortException e) {
 			sendAbort(e.getCause() != null);
 			throw e;

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementTaskImpl.java

@@ -114,9 +114,9 @@ class KeyAgreementTaskImpl extends Thread implements KeyAgreementTask,
 				keyAgreementCrypto, payloadEncoder, transport, remotePayload,
 				localPayload, localKeyPair, alice);
 		try {
-			SecretKey master = protocol.perform();
+			SecretKey masterKey = protocol.perform();
 			KeyAgreementResult result =
-					new KeyAgreementResult(master, transport.getConnection(),
+					new KeyAgreementResult(masterKey, transport.getConnection(),
 							transport.getTransportId(), alice);
 			LOG.info("Finished BQP protocol");
 			// Broadcast result to caller

bramble-core/src/main/java/org/briarproject/bramble/transport/KeyManagerImpl.java

@@ -19,8 +19,8 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -95,22 +95,22 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 	}
 
 	@Override
-	public Map<TransportId, KeySetId> addContact(Transaction txn, ContactId c,
+	public Map<TransportId, TransportKeySetId> addContact(Transaction txn,
-			SecretKey master, long timestamp, boolean alice, boolean active)
+			ContactId c, SecretKey rootKey, long timestamp, boolean alice,
-			throws DbException {
+			boolean active) throws DbException {
-		Map<TransportId, KeySetId> ids = new HashMap<>();
+		Map<TransportId, TransportKeySetId> ids = new HashMap<>();
 		for (Entry<TransportId, TransportKeyManager> e : managers.entrySet()) {
 			TransportId t = e.getKey();
 			TransportKeyManager m = e.getValue();
-			ids.put(t, m.addContact(txn, c, master, timestamp, alice, active));
+			ids.put(t, m.addContact(txn, c, rootKey, timestamp, alice, active));
 		}
 		return ids;
 	}
 
 	@Override
-	public void activateKeys(Transaction txn, Map<TransportId, KeySetId> keys)
+	public void activateKeys(Transaction txn, Map<TransportId,
-			throws DbException {
+			TransportKeySetId> keys) throws DbException {
-		for (Entry<TransportId, KeySetId> e : keys.entrySet()) {
+		for (Entry<TransportId, TransportKeySetId> e : keys.entrySet()) {
 			TransportId t = e.getKey();
 			TransportKeyManager m = managers.get(t);
 			if (m == null) {

bramble-core/src/main/java/org/briarproject/bramble/transport/MutableIncomingKeys.java

@@ -11,18 +11,18 @@ import javax.annotation.concurrent.NotThreadSafe;
 class MutableIncomingKeys {
 
 	private final SecretKey tagKey, headerKey;
-	private final long rotationPeriod;
+	private final long timePeriod;
 	private final ReorderingWindow window;
 
 	MutableIncomingKeys(IncomingKeys in) {
 		tagKey = in.getTagKey();
 		headerKey = in.getHeaderKey();
-		rotationPeriod = in.getRotationPeriod();
+		timePeriod = in.getTimePeriod();
 		window = new ReorderingWindow(in.getWindowBase(), in.getWindowBitmap());
 	}
 
 	IncomingKeys snapshot() {
-		return new IncomingKeys(tagKey, headerKey, rotationPeriod,
+		return new IncomingKeys(tagKey, headerKey, timePeriod,
 				window.getBase(), window.getBitmap());
 	}
 
@@ -34,8 +34,8 @@ class MutableIncomingKeys {
 		return headerKey;
 	}
 
-	long getRotationPeriod() {
+	long getTimePeriod() {
-		return rotationPeriod;
+		return timePeriod;
 	}
 
 	ReorderingWindow getWindow() {

bramble-core/src/main/java/org/briarproject/bramble/transport/MutableKeySet.java

@@ -1,22 +1,22 @@
 package org.briarproject.bramble.transport;
 
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 
 class MutableKeySet {
 
-	private final KeySetId keySetId;
+	private final TransportKeySetId keySetId;
 	private final ContactId contactId;
 	private final MutableTransportKeys transportKeys;
 
-	MutableKeySet(KeySetId keySetId, ContactId contactId,
+	MutableKeySet(TransportKeySetId keySetId, ContactId contactId,
 			MutableTransportKeys transportKeys) {
 		this.keySetId = keySetId;
 		this.contactId = contactId;
 		this.transportKeys = transportKeys;
 	}
 
-	KeySetId getKeySetId() {
+	TransportKeySetId getKeySetId() {
 		return keySetId;
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/transport/MutableOutgoingKeys.java

@@ -11,20 +11,20 @@ import javax.annotation.concurrent.NotThreadSafe;
 class MutableOutgoingKeys {
 
 	private final SecretKey tagKey, headerKey;
-	private final long rotationPeriod;
+	private final long timePeriod;
 	private long streamCounter;
 	private boolean active;
 
 	MutableOutgoingKeys(OutgoingKeys out) {
 		tagKey = out.getTagKey();
 		headerKey = out.getHeaderKey();
-		rotationPeriod = out.getRotationPeriod();
+		timePeriod = out.getTimePeriod();
 		streamCounter = out.getStreamCounter();
 		active = out.isActive();
 	}
 
 	OutgoingKeys snapshot() {
-		return new OutgoingKeys(tagKey, headerKey, rotationPeriod,
+		return new OutgoingKeys(tagKey, headerKey, timePeriod,
 				streamCounter, active);
 	}
 
@@ -36,8 +36,8 @@ class MutableOutgoingKeys {
 		return headerKey;
 	}
 
-	long getRotationPeriod() {
+	long getTimePeriod() {
-		return rotationPeriod;
+		return timePeriod;
 	}
 
 	long getStreamCounter() {

bramble-core/src/main/java/org/briarproject/bramble/transport/TransportKeyManager.java

@@ -5,8 +5,8 @@ import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 
 import javax.annotation.Nullable;
 
@@ -15,10 +15,11 @@ interface TransportKeyManager {
 
 	void start(Transaction txn) throws DbException;
 
-	KeySetId addContact(Transaction txn, ContactId c, SecretKey master,
+	TransportKeySetId addContact(Transaction txn, ContactId c,
-			long timestamp, boolean alice, boolean active) throws DbException;
+			SecretKey rootKey, long timestamp, boolean alice, boolean active)
+			throws DbException;
 
-	void activateKeys(Transaction txn, KeySetId k) throws DbException;
+	void activateKeys(Transaction txn, TransportKeySetId k) throws DbException;
 
 	void removeContact(ContactId c);
 

bramble-core/src/main/java/org/briarproject/bramble/transport/TransportKeyManagerImpl.java

@@ -11,9 +11,9 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.Scheduler;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.transport.ReorderingWindow.Change;
 
@@ -51,12 +51,12 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	private final ScheduledExecutorService scheduler;
 	private final Clock clock;
 	private final TransportId transportId;
-	private final long rotationPeriodLength;
+	private final long timePeriodLength;
 	private final AtomicBoolean used = new AtomicBoolean(false);
 	private final ReentrantLock lock = new ReentrantLock();
 
 	// The following are locking: lock
-	private final Map<KeySetId, MutableKeySet> keys = new HashMap<>();
+	private final Map<TransportKeySetId, MutableKeySet> keys = new HashMap<>();
 	private final Map<Bytes, TagContext> inContexts = new HashMap<>();
 	private final Map<ContactId, MutableKeySet> outContexts = new HashMap<>();
 
@@ -70,7 +70,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		this.scheduler = scheduler;
 		this.clock = clock;
 		this.transportId = transportId;
-		rotationPeriodLength = maxLatency + MAX_CLOCK_DIFFERENCE;
+		timePeriodLength = maxLatency + MAX_CLOCK_DIFFERENCE;
 	}
 
 	@Override
@@ -80,8 +80,9 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		lock.lock();
 		try {
 			// Load the transport keys from the DB
-			Collection<KeySet> loaded = db.getTransportKeys(txn, transportId);
+			Collection<TransportKeySet> loaded =
-			// Rotate the keys to the current rotation period
+					db.getTransportKeys(txn, transportId);
+			// Rotate the keys to the current time period
 			RotationResult rotationResult = rotateKeys(loaded, now);
 			// Initialise mutable state for all contacts
 			addKeys(rotationResult.current);
@@ -95,15 +96,17 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		scheduleKeyRotation(now);
 	}
 
-	private RotationResult rotateKeys(Collection<KeySet> keys, long now) {
+	private RotationResult rotateKeys(Collection<TransportKeySet> keys,
+			long now) {
 		RotationResult rotationResult = new RotationResult();
-		long rotationPeriod = now / rotationPeriodLength;
+		long timePeriod = now / timePeriodLength;
-		for (KeySet ks : keys) {
+		for (TransportKeySet ks : keys) {
-			TransportKeys k = ks.getTransportKeys();
+			TransportKeys k = ks.getKeys();
-			TransportKeys k1 =
+			TransportKeys k1 = transportCrypto.rotateTransportKeys(k,
-					transportCrypto.rotateTransportKeys(k, rotationPeriod);
+					timePeriod);
-			KeySet ks1 = new KeySet(ks.getKeySetId(), ks.getContactId(), k1);
+			TransportKeySet ks1 = new TransportKeySet(ks.getKeySetId(),
-			if (k1.getRotationPeriod() > k.getRotationPeriod())
+					ks.getContactId(), k1);
+			if (k1.getTimePeriod() > k.getTimePeriod())
 				rotationResult.rotated.add(ks1);
 			rotationResult.current.add(ks1);
 		}
@@ -111,15 +114,15 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	// Locking: lock
-	private void addKeys(Collection<KeySet> keys) {
+	private void addKeys(Collection<TransportKeySet> keys) {
-		for (KeySet ks : keys) {
+		for (TransportKeySet ks : keys) {
 			addKeys(ks.getKeySetId(), ks.getContactId(),
-					new MutableTransportKeys(ks.getTransportKeys()));
+					new MutableTransportKeys(ks.getKeys()));
 		}
 	}
 
 	// Locking: lock
-	private void addKeys(KeySetId keySetId, ContactId contactId,
+	private void addKeys(TransportKeySetId keySetId, ContactId contactId,
 			MutableTransportKeys m) {
 		MutableKeySet ks = new MutableKeySet(keySetId, contactId, m);
 		keys.put(keySetId, ks);
@@ -130,7 +133,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	// Locking: lock
-	private void encodeTags(KeySetId keySetId, ContactId contactId,
+	private void encodeTags(TransportKeySetId keySetId, ContactId contactId,
 			MutableIncomingKeys inKeys) {
 		for (long streamNumber : inKeys.getWindow().getUnseen()) {
 			TagContext tagCtx =
@@ -155,7 +158,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	private void scheduleKeyRotation(long now) {
-		long delay = rotationPeriodLength - now % rotationPeriodLength;
+		long delay = timePeriodLength - now % timePeriodLength;
 		scheduler.schedule((Runnable) this::rotateKeys, delay, MILLISECONDS);
 	}
 
@@ -170,20 +173,21 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	@Override
-	public KeySetId addContact(Transaction txn, ContactId c, SecretKey master,
+	public TransportKeySetId addContact(Transaction txn, ContactId c,
-			long timestamp, boolean alice, boolean active) throws DbException {
+			SecretKey rootKey, long timestamp, boolean alice, boolean active)
+			throws DbException {
 		lock.lock();
 		try {
-			// Work out what rotation period the timestamp belongs to
+			// Work out what time period the timestamp belongs to
-			long rotationPeriod = timestamp / rotationPeriodLength;
+			long timePeriod = timestamp / timePeriodLength;
 			// Derive the transport keys
 			TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
-					master, rotationPeriod, alice, active);
+					rootKey, timePeriod, alice, active);
-			// Rotate the keys to the current rotation period if necessary
+			// Rotate the keys to the current time period if necessary
-			rotationPeriod = clock.currentTimeMillis() / rotationPeriodLength;
+			timePeriod = clock.currentTimeMillis() / timePeriodLength;
-			k = transportCrypto.rotateTransportKeys(k, rotationPeriod);
+			k = transportCrypto.rotateTransportKeys(k, timePeriod);
 			// Write the keys back to the DB
-			KeySetId keySetId = db.addTransportKeys(txn, c, k);
+			TransportKeySetId keySetId = db.addTransportKeys(txn, c, k);
 			// Initialise mutable state for the contact
 			addKeys(keySetId, c, new MutableTransportKeys(k));
 			return keySetId;
@@ -193,7 +197,8 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	@Override
-	public void activateKeys(Transaction txn, KeySetId k) throws DbException {
+	public void activateKeys(Transaction txn, TransportKeySetId k)
+			throws DbException {
 		lock.lock();
 		try {
 			MutableKeySet ks = keys.get(k);
@@ -300,7 +305,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 			}
 			// Write the window back to the DB
 			db.setReorderingWindow(txn, tagCtx.keySetId, transportId,
-					inKeys.getRotationPeriod(), window.getBase(),
+					inKeys.getTimePeriod(), window.getBase(),
 					window.getBitmap());
 			// If the outgoing keys are inactive, activate them
 			MutableKeySet ks = keys.get(tagCtx.keySetId);
@@ -322,11 +327,11 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		long now = clock.currentTimeMillis();
 		lock.lock();
 		try {
-			// Rotate the keys to the current rotation period
+			// Rotate the keys to the current time period
-			Collection<KeySet> snapshot = new ArrayList<>(keys.size());
+			Collection<TransportKeySet> snapshot = new ArrayList<>(keys.size());
 			for (MutableKeySet ks : keys.values()) {
-				snapshot.add(new KeySet(ks.getKeySetId(), ks.getContactId(),
+				snapshot.add(new TransportKeySet(ks.getKeySetId(),
-						ks.getTransportKeys().snapshot()));
+						ks.getContactId(), ks.getTransportKeys().snapshot()));
 			}
 			RotationResult rotationResult = rotateKeys(snapshot, now);
 			// Rebuild the mutable state for all contacts
@@ -346,12 +351,12 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 
 	private static class TagContext {
 
-		private final KeySetId keySetId;
+		private final TransportKeySetId keySetId;
 		private final ContactId contactId;
 		private final MutableIncomingKeys inKeys;
 		private final long streamNumber;
 
-		private TagContext(KeySetId keySetId, ContactId contactId,
+		private TagContext(TransportKeySetId keySetId, ContactId contactId,
 				MutableIncomingKeys inKeys, long streamNumber) {
 			this.keySetId = keySetId;
 			this.contactId = contactId;
@@ -362,7 +367,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 
 	private static class RotationResult {
 
-		private final Collection<KeySet> current = new ArrayList<>();
+		private final Collection<TransportKeySet> current = new ArrayList<>();
-		private final Collection<KeySet> rotated = new ArrayList<>();
+		private final Collection<TransportKeySet> rotated = new ArrayList<>();
 	}
 }

bramble-core/src/test/java/org/briarproject/bramble/contact/ContactManagerImplTest.java

@@ -64,7 +64,7 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testAddContact() throws Exception {
-		SecretKey master = getSecretKey();
+		SecretKey rootKey = getSecretKey();
 		long timestamp = System.currentTimeMillis();
 		boolean alice = new Random().nextBoolean();
 		Transaction txn = new Transaction(null, false);
@@ -73,14 +73,14 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).transactionWithResult(with(false), withDbCallable(txn));
 			oneOf(db).addContact(txn, remote, local, verified, active);
 			will(returnValue(contactId));
-			oneOf(keyManager).addContact(txn, contactId, master, timestamp,
+			oneOf(keyManager).addContact(txn, contactId, rootKey, timestamp,
 					alice, active);
 			oneOf(db).getContact(txn, contactId);
 			will(returnValue(contact));
 		}});
 
 		assertEquals(contactId, contactManager.addContact(remote, local,
-				master, timestamp, alice, verified, active));
+				rootKey, timestamp, alice, verified, active));
 	}
 
 	@Test

bramble-core/src/test/java/org/briarproject/bramble/crypto/HandshakeKeyDerivationTest.java

@@ -0,0 +1,167 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.crypto.TransportCrypto;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
+import org.junit.Test;
+
+import java.util.Arrays;
+
+import static org.briarproject.bramble.crypto.KeyDerivationTestUtils.assertAllDifferent;
+import static org.briarproject.bramble.crypto.KeyDerivationTestUtils.assertMatches;
+import static org.briarproject.bramble.test.TestUtils.getSecretKey;
+import static org.briarproject.bramble.test.TestUtils.getTransportId;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertSame;
+
+public class HandshakeKeyDerivationTest extends BrambleTestCase {
+
+	private final CryptoComponent crypto =
+			new CryptoComponentImpl(new TestSecureRandomProvider(), null);
+	private final TransportCrypto transportCrypto =
+			new TransportCryptoImpl(crypto);
+	private final TransportId transportId = getTransportId();
+	private final SecretKey rootKey = getSecretKey();
+
+	@Test
+	public void testKeysAreDistinct() {
+		HandshakeKeys kA = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys kB = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, false);
+		assertAllDifferent(kA);
+		assertAllDifferent(kB);
+	}
+
+	@Test
+	public void testKeysAreNotUpdatedToPreviousPeriod() {
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.updateHandshakeKeys(k, 122);
+		assertSame(k, k1);
+	}
+
+	@Test
+	public void testKeysAreNotUpdatedToCurrentPeriod() {
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.updateHandshakeKeys(k, 123);
+		assertSame(k, k1);
+	}
+
+	@Test
+	public void testKeysAreUpdatedByOnePeriod() {
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.updateHandshakeKeys(k, 124);
+		assertSame(k.getCurrentIncomingKeys(), k1.getPreviousIncomingKeys());
+		assertSame(k.getNextIncomingKeys(), k1.getCurrentIncomingKeys());
+	}
+
+	@Test
+	public void testKeysAreUpdatedByTwoPeriods() {
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.updateHandshakeKeys(k, 125);
+		assertSame(k.getNextIncomingKeys(), k1.getPreviousIncomingKeys());
+	}
+
+	@Test
+	public void testKeysAreUpdatedByThreePeriods() {
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.updateHandshakeKeys(k, 126);
+		assertAllDifferent(k, k1);
+	}
+
+	@Test
+	public void testCurrentKeysMatchContact() {
+		// Start in time period 123
+		HandshakeKeys kA = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys kB = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, false);
+		// Alice's incoming keys should equal Bob's outgoing keys
+		assertMatches(kA.getCurrentIncomingKeys(), kB.getCurrentOutgoingKeys());
+		// Bob's incoming keys should equal Alice's outgoing keys
+		assertMatches(kB.getCurrentIncomingKeys(), kA.getCurrentOutgoingKeys());
+		// Update into the future
+		kA = transportCrypto.updateHandshakeKeys(kA, 456);
+		kB = transportCrypto.updateHandshakeKeys(kB, 456);
+		// Alice's incoming keys should equal Bob's outgoing keys
+		assertMatches(kA.getCurrentIncomingKeys(), kB.getCurrentOutgoingKeys());
+		// Bob's incoming keys should equal Alice's outgoing keys
+		assertMatches(kB.getCurrentIncomingKeys(), kA.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testPreviousKeysMatchContact() {
+		// Start in time period 123
+		HandshakeKeys kA = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys kB = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, false);
+		// Compare Alice's previous keys in period 456 with Bob's current keys
+		// in period 455
+		kA = transportCrypto.updateHandshakeKeys(kA, 456);
+		kB = transportCrypto.updateHandshakeKeys(kB, 455);
+		// Alice's previous incoming keys should equal Bob's current
+		// outgoing keys
+		assertMatches(kA.getPreviousIncomingKeys(),
+				kB.getCurrentOutgoingKeys());
+		// Compare Alice's current keys in period 456 with Bob's previous keys
+		// in period 457
+		kB = transportCrypto.updateHandshakeKeys(kB, 457);
+		// Bob's previous incoming keys should equal Alice's current
+		// outgoing keys
+		assertMatches(kB.getPreviousIncomingKeys(),
+				kA.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testNextKeysMatchContact() {
+		// Start in time period 123
+		HandshakeKeys kA = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys kB = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, false);
+		// Compare Alice's current keys in period 456 with Bob's next keys in
+		// period 455
+		kA = transportCrypto.updateHandshakeKeys(kA, 456);
+		kB = transportCrypto.updateHandshakeKeys(kB, 455);
+		// Bob's next incoming keys should equal Alice's current outgoing keys
+		assertMatches(kB.getNextIncomingKeys(), kA.getCurrentOutgoingKeys());
+		// Compare Alice's next keys in period 456 with Bob's current keys
+		// in period 457
+		kB = transportCrypto.updateHandshakeKeys(kB, 457);
+		// Alice's next incoming keys should equal Bob's current outgoing keys
+		assertMatches(kA.getNextIncomingKeys(), kB.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testRootKeyAffectsOutput() {
+		SecretKey rootKey1 = getSecretKey();
+		assertFalse(Arrays.equals(rootKey.getBytes(), rootKey1.getBytes()));
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey1, 123, true);
+		assertAllDifferent(k, k1);
+	}
+
+	@Test
+	public void testTransportIdAffectsOutput() {
+		TransportId transportId1 = getTransportId();
+		assertNotEquals(transportId.getString(), transportId1.getString());
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.deriveHandshakeKeys(transportId1,
+				rootKey, 123, true);
+		assertAllDifferent(k, k1);
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/crypto/KeyDerivationTest.java

@@ -1,167 +0,0 @@
-package org.briarproject.bramble.crypto;
-
-import org.briarproject.bramble.api.Bytes;
-import org.briarproject.bramble.api.crypto.CryptoComponent;
-import org.briarproject.bramble.api.crypto.SecretKey;
-import org.briarproject.bramble.api.crypto.TransportCrypto;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.transport.TransportKeys;
-import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestSecureRandomProvider;
-import org.junit.Test;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-
-import static org.briarproject.bramble.test.TestUtils.getSecretKey;
-import static org.briarproject.bramble.test.TestUtils.getTransportId;
-import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-public class KeyDerivationTest extends BrambleTestCase {
-
-	private final CryptoComponent crypto =
-			new CryptoComponentImpl(new TestSecureRandomProvider(), null);
-	private final TransportCrypto transportCrypto =
-			new TransportCryptoImpl(crypto);
-	private final TransportId transportId = getTransportId();
-	private final SecretKey master = getSecretKey();
-
-	@Test
-	public void testKeysAreDistinct() {
-		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		assertAllDifferent(k);
-	}
-
-	@Test
-	public void testCurrentKeysMatchCurrentKeysOfContact() {
-		// Start in rotation period 123
-		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, false, true);
-		// Alice's incoming keys should equal Bob's outgoing keys
-		assertArrayEquals(kA.getCurrentIncomingKeys().getTagKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentIncomingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getHeaderKey().getBytes());
-		// Alice's outgoing keys should equal Bob's incoming keys
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getTagKey().getBytes(),
-				kB.getCurrentIncomingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentIncomingKeys().getHeaderKey().getBytes());
-		// Rotate into the future
-		kA = transportCrypto.rotateTransportKeys(kA, 456);
-		kB = transportCrypto.rotateTransportKeys(kB, 456);
-		// Alice's incoming keys should equal Bob's outgoing keys
-		assertArrayEquals(kA.getCurrentIncomingKeys().getTagKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentIncomingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getHeaderKey().getBytes());
-		// Alice's outgoing keys should equal Bob's incoming keys
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getTagKey().getBytes(),
-				kB.getCurrentIncomingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentIncomingKeys().getHeaderKey().getBytes());
-	}
-
-	@Test
-	public void testPreviousKeysMatchPreviousKeysOfContact() {
-		// Start in rotation period 123
-		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, false, true);
-		// Compare Alice's previous keys in period 456 with Bob's current keys
-		// in period 455
-		kA = transportCrypto.rotateTransportKeys(kA, 456);
-		kB = transportCrypto.rotateTransportKeys(kB, 455);
-		// Alice's previous incoming keys should equal Bob's outgoing keys
-		assertArrayEquals(kA.getPreviousIncomingKeys().getTagKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getTagKey().getBytes());
-		assertArrayEquals(
-				kA.getPreviousIncomingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getHeaderKey().getBytes());
-		// Compare Alice's current keys in period 456 with Bob's previous keys
-		// in period 457
-		kB = transportCrypto.rotateTransportKeys(kB, 457);
-		// Alice's outgoing keys should equal Bob's previous incoming keys
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getTagKey().getBytes(),
-				kB.getPreviousIncomingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getHeaderKey().getBytes(),
-				kB.getPreviousIncomingKeys().getHeaderKey().getBytes());
-	}
-
-	@Test
-	public void testNextKeysMatchNextKeysOfContact() {
-		// Start in rotation period 123
-		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, false, true);
-		// Compare Alice's current keys in period 456 with Bob's next keys in
-		// period 455
-		kA = transportCrypto.rotateTransportKeys(kA, 456);
-		kB = transportCrypto.rotateTransportKeys(kB, 455);
-		// Alice's outgoing keys should equal Bob's next incoming keys
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getTagKey().getBytes(),
-				kB.getNextIncomingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getHeaderKey().getBytes(),
-				kB.getNextIncomingKeys().getHeaderKey().getBytes());
-		// Compare Alice's next keys in period 456 with Bob's current keys
-		// in period 457
-		kB = transportCrypto.rotateTransportKeys(kB, 457);
-		// Alice's next incoming keys should equal Bob's outgoing keys
-		assertArrayEquals(kA.getNextIncomingKeys().getTagKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getNextIncomingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getHeaderKey().getBytes());
-	}
-
-	@Test
-	public void testMasterKeyAffectsOutput() {
-		SecretKey master1 = getSecretKey();
-		assertFalse(Arrays.equals(master.getBytes(), master1.getBytes()));
-		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		TransportKeys k1 = transportCrypto.deriveTransportKeys(transportId,
-				master1, 123, true, true);
-		assertAllDifferent(k, k1);
-	}
-
-	@Test
-	public void testTransportIdAffectsOutput() {
-		TransportId transportId1 = getTransportId();
-		assertFalse(transportId.getString().equals(transportId1.getString()));
-		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		TransportKeys k1 = transportCrypto.deriveTransportKeys(transportId1,
-				master, 123, true, true);
-		assertAllDifferent(k, k1);
-	}
-
-	private void assertAllDifferent(TransportKeys... transportKeys) {
-		List<SecretKey> secretKeys = new ArrayList<>();
-		for (TransportKeys k : transportKeys) {
-			secretKeys.add(k.getPreviousIncomingKeys().getTagKey());
-			secretKeys.add(k.getPreviousIncomingKeys().getHeaderKey());
-			secretKeys.add(k.getCurrentIncomingKeys().getTagKey());
-			secretKeys.add(k.getCurrentIncomingKeys().getHeaderKey());
-			secretKeys.add(k.getNextIncomingKeys().getTagKey());
-			secretKeys.add(k.getNextIncomingKeys().getHeaderKey());
-			secretKeys.add(k.getCurrentOutgoingKeys().getTagKey());
-			secretKeys.add(k.getCurrentOutgoingKeys().getHeaderKey());
-		}
-		assertAllDifferent(secretKeys);
-	}
-
-	private void assertAllDifferent(List<SecretKey> keys) {
-		Set<Bytes> set = new HashSet<>();
-		for (SecretKey k : keys) assertTrue(set.add(new Bytes(k.getBytes())));
-	}
-}

bramble-core/src/test/java/org/briarproject/bramble/crypto/KeyDerivationTestUtils.java

@@ -0,0 +1,45 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.Bytes;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.transport.AbstractTransportKeys;
+import org.briarproject.bramble.api.transport.IncomingKeys;
+import org.briarproject.bramble.api.transport.OutgoingKeys;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertTrue;
+
+class KeyDerivationTestUtils {
+
+	static void assertAllDifferent(AbstractTransportKeys... transportKeys) {
+		List<SecretKey> secretKeys = new ArrayList<>();
+		for (AbstractTransportKeys k : transportKeys) {
+			secretKeys.add(k.getPreviousIncomingKeys().getTagKey());
+			secretKeys.add(k.getPreviousIncomingKeys().getHeaderKey());
+			secretKeys.add(k.getCurrentIncomingKeys().getTagKey());
+			secretKeys.add(k.getCurrentIncomingKeys().getHeaderKey());
+			secretKeys.add(k.getNextIncomingKeys().getTagKey());
+			secretKeys.add(k.getNextIncomingKeys().getHeaderKey());
+			secretKeys.add(k.getCurrentOutgoingKeys().getTagKey());
+			secretKeys.add(k.getCurrentOutgoingKeys().getHeaderKey());
+		}
+		assertAllDifferent(secretKeys);
+	}
+
+	static void assertAllDifferent(List<SecretKey> keys) {
+		Set<Bytes> set = new HashSet<>();
+		for (SecretKey k : keys) assertTrue(set.add(new Bytes(k.getBytes())));
+	}
+
+	static void assertMatches(IncomingKeys in, OutgoingKeys out) {
+		assertArrayEquals(in.getTagKey().getBytes(),
+				out.getTagKey().getBytes());
+		assertArrayEquals(in.getHeaderKey().getBytes(),
+				out.getHeaderKey().getBytes());
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/crypto/TransportKeyDerivationTest.java

@@ -0,0 +1,167 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.crypto.TransportCrypto;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.transport.TransportKeys;
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
+import org.junit.Test;
+
+import java.util.Arrays;
+
+import static org.briarproject.bramble.crypto.KeyDerivationTestUtils.assertAllDifferent;
+import static org.briarproject.bramble.crypto.KeyDerivationTestUtils.assertMatches;
+import static org.briarproject.bramble.test.TestUtils.getSecretKey;
+import static org.briarproject.bramble.test.TestUtils.getTransportId;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertSame;
+
+public class TransportKeyDerivationTest extends BrambleTestCase {
+
+	private final CryptoComponent crypto =
+			new CryptoComponentImpl(new TestSecureRandomProvider(), null);
+	private final TransportCrypto transportCrypto =
+			new TransportCryptoImpl(crypto);
+	private final TransportId transportId = getTransportId();
+	private final SecretKey rootKey = getSecretKey();
+
+	@Test
+	public void testKeysAreDistinct() {
+		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, false, true);
+		assertAllDifferent(kA);
+		assertAllDifferent(kB);
+	}
+
+	@Test
+	public void testKeysAreNotRotatedToPreviousPeriod() {
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.rotateTransportKeys(k, 122);
+		assertSame(k, k1);
+	}
+
+	@Test
+	public void testKeysAreNotRotatedToCurrentPeriod() {
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.rotateTransportKeys(k, 123);
+		assertSame(k, k1);
+	}
+
+	@Test
+	public void testKeysAreRotatedByOnePeriod() {
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.rotateTransportKeys(k, 124);
+		assertSame(k.getCurrentIncomingKeys(), k1.getPreviousIncomingKeys());
+		assertSame(k.getNextIncomingKeys(), k1.getCurrentIncomingKeys());
+	}
+
+	@Test
+	public void testKeysAreRotatedByTwoPeriods() {
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.rotateTransportKeys(k, 125);
+		assertSame(k.getNextIncomingKeys(), k1.getPreviousIncomingKeys());
+	}
+
+	@Test
+	public void testKeysAreRotatedByThreePeriods() {
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.rotateTransportKeys(k, 126);
+		assertAllDifferent(k, k1);
+	}
+
+	@Test
+	public void testCurrentKeysMatchContact() {
+		// Start in time period 123
+		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, false, true);
+		// Alice's incoming keys should equal Bob's outgoing keys
+		assertMatches(kA.getCurrentIncomingKeys(), kB.getCurrentOutgoingKeys());
+		// Bob's incoming keys should equal Alice's outgoing keys
+		assertMatches(kB.getCurrentIncomingKeys(), kA.getCurrentOutgoingKeys());
+		// Rotate into the future
+		kA = transportCrypto.rotateTransportKeys(kA, 456);
+		kB = transportCrypto.rotateTransportKeys(kB, 456);
+		// Alice's incoming keys should equal Bob's outgoing keys
+		assertMatches(kA.getCurrentIncomingKeys(), kB.getCurrentOutgoingKeys());
+		// Bob's incoming keys should equal Alice's outgoing keys
+		assertMatches(kB.getCurrentIncomingKeys(), kA.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testPreviousKeysMatchContact() {
+		// Start in time period 123
+		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, false, true);
+		// Compare Alice's previous keys in period 456 with Bob's current keys
+		// in period 455
+		kA = transportCrypto.rotateTransportKeys(kA, 456);
+		kB = transportCrypto.rotateTransportKeys(kB, 455);
+		// Alice's previous incoming keys should equal Bob's current
+		// outgoing keys
+		assertMatches(kA.getPreviousIncomingKeys(),
+				kB.getCurrentOutgoingKeys());
+		// Compare Alice's current keys in period 456 with Bob's previous keys
+		// in period 457
+		kB = transportCrypto.rotateTransportKeys(kB, 457);
+		// Bob's previous incoming keys should equal Alice's current
+		// outgoing keys
+		assertMatches(kB.getPreviousIncomingKeys(),
+				kA.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testNextKeysMatchContact() {
+		// Start in time period 123
+		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, false, true);
+		// Compare Alice's current keys in period 456 with Bob's next keys in
+		// period 455
+		kA = transportCrypto.rotateTransportKeys(kA, 456);
+		kB = transportCrypto.rotateTransportKeys(kB, 455);
+		// Bob's next incoming keys should equal Alice's current outgoing keys
+		assertMatches(kB.getNextIncomingKeys(), kA.getCurrentOutgoingKeys());
+		// Compare Alice's next keys in period 456 with Bob's current keys
+		// in period 457
+		kB = transportCrypto.rotateTransportKeys(kB, 457);
+		// Alice's next incoming keys should equal Bob's current outgoing keys
+		assertMatches(kA.getNextIncomingKeys(), kB.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testRootKeyAffectsOutput() {
+		SecretKey rootKey1 = getSecretKey();
+		assertFalse(Arrays.equals(rootKey.getBytes(), rootKey1.getBytes()));
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.deriveTransportKeys(transportId,
+				rootKey1, 123, true, true);
+		assertAllDifferent(k, k1);
+	}
+
+	@Test
+	public void testTransportIdAffectsOutput() {
+		TransportId transportId1 = getTransportId();
+		assertNotEquals(transportId.getString(), transportId1.getString());
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.deriveTransportKeys(transportId1,
+				rootKey, 123, true, true);
+		assertAllDifferent(k, k1);
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseComponentImplTest.java

@@ -2,6 +2,7 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
 import org.briarproject.bramble.api.contact.event.ContactStatusChangedEvent;
@@ -13,6 +14,7 @@ import org.briarproject.bramble.api.db.NoSuchContactException;
 import org.briarproject.bramble.api.db.NoSuchGroupException;
 import org.briarproject.bramble.api.db.NoSuchLocalAuthorException;
 import org.briarproject.bramble.api.db.NoSuchMessageException;
+import org.briarproject.bramble.api.db.NoSuchPendingContactException;
 import org.briarproject.bramble.api.db.NoSuchTransportException;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
@@ -44,10 +46,11 @@ import org.briarproject.bramble.api.sync.event.MessageToAckEvent;
 import org.briarproject.bramble.api.sync.event.MessageToRequestEvent;
 import org.briarproject.bramble.api.sync.event.MessagesAckedEvent;
 import org.briarproject.bramble.api.sync.event.MessagesSentEvent;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
 import org.briarproject.bramble.api.transport.IncomingKeys;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.CaptureArgumentAction;
@@ -111,7 +114,8 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 	private final int maxLatency;
 	private final ContactId contactId;
 	private final Contact contact;
-	private final KeySetId keySetId;
+	private final TransportKeySetId keySetId;
+	private final PendingContactId pendingContactId;
 
 	public DatabaseComponentImplTest() {
 		clientId = getClientId();
@@ -132,7 +136,8 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		contactId = new ContactId(234);
 		contact = new Contact(contactId, author, localAuthor.getId(), alias,
 				true, true);
-		keySetId = new KeySetId(345);
+		keySetId = new TransportKeySetId(345);
+		pendingContactId = new PendingContactId(getRandomId());
 	}
 
 	private DatabaseComponent createDatabaseComponent(Database<Object> database,
@@ -279,15 +284,24 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			throws Exception {
 		context.checking(new Expectations() {{
 			// Check whether the contact is in the DB (which it's not)
-			exactly(17).of(database).startTransaction();
+			exactly(18).of(database).startTransaction();
 			will(returnValue(txn));
-			exactly(17).of(database).containsContact(txn, contactId);
+			exactly(18).of(database).containsContact(txn, contactId);
 			will(returnValue(false));
-			exactly(17).of(database).abortTransaction(txn);
+			exactly(18).of(database).abortTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
 				eventExecutor, shutdownManager);
 
+		try {
+			db.transaction(false, transaction ->
+					db.addHandshakeKeys(transaction, contactId,
+							createHandshakeKeys()));
+			fail();
+		} catch (NoSuchContactException expected) {
+			// Expected
+		}
+
 		try {
 			db.transaction(false, transaction ->
 					db.addTransportKeys(transaction, contactId,
@@ -718,6 +732,39 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 	}
 
+	@Test
+	public void testVariousMethodsThrowExceptionIfPendingContactIsMissing()
+			throws Exception {
+		context.checking(new Expectations() {{
+			// Check whether the pending contact is in the DB (which it's not)
+			exactly(2).of(database).startTransaction();
+			will(returnValue(txn));
+			exactly(2).of(database).containsPendingContact(txn,
+					pendingContactId);
+			will(returnValue(false));
+			exactly(2).of(database).abortTransaction(txn);
+		}});
+		DatabaseComponent db = createDatabaseComponent(database, eventBus,
+				eventExecutor, shutdownManager);
+
+		try {
+			db.transaction(false, transaction ->
+					db.addHandshakeKeys(transaction, pendingContactId,
+							createHandshakeKeys()));
+			fail();
+		} catch (NoSuchPendingContactException expected) {
+			// Expected
+		}
+
+		try {
+			db.transaction(false, transaction ->
+					db.removePendingContact(transaction, pendingContactId));
+			fail();
+		} catch (NoSuchPendingContactException expected) {
+			// Expected
+		}
+	}
+
 	@Test
 	public void testGenerateAck() throws Exception {
 		Collection<MessageId> messagesToAck = asList(messageId, messageId1);
@@ -1117,8 +1164,9 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 	@Test
 	public void testTransportKeys() throws Exception {
 		TransportKeys transportKeys = createTransportKeys();
-		KeySet ks = new KeySet(keySetId, contactId, transportKeys);
+		TransportKeySet ks =
-		Collection<KeySet> keys = singletonList(ks);
+				new TransportKeySet(keySetId, contactId, transportKeys);
+		Collection<TransportKeySet> keys = singletonList(ks);
 
 		context.checking(new Expectations() {{
 			// startTransaction()
@@ -1245,6 +1293,27 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		});
 	}
 
+	private HandshakeKeys createHandshakeKeys() {
+		SecretKey inPrevTagKey = getSecretKey();
+		SecretKey inPrevHeaderKey = getSecretKey();
+		IncomingKeys inPrev = new IncomingKeys(inPrevTagKey, inPrevHeaderKey,
+				1, 123, new byte[4]);
+		SecretKey inCurrTagKey = getSecretKey();
+		SecretKey inCurrHeaderKey = getSecretKey();
+		IncomingKeys inCurr = new IncomingKeys(inCurrTagKey, inCurrHeaderKey,
+				2, 234, new byte[4]);
+		SecretKey inNextTagKey = getSecretKey();
+		SecretKey inNextHeaderKey = getSecretKey();
+		IncomingKeys inNext = new IncomingKeys(inNextTagKey, inNextHeaderKey,
+				3, 345, new byte[4]);
+		SecretKey outCurrTagKey = getSecretKey();
+		SecretKey outCurrHeaderKey = getSecretKey();
+		OutgoingKeys outCurr = new OutgoingKeys(outCurrTagKey, outCurrHeaderKey,
+				2, 456, true);
+		return new HandshakeKeys(transportId, inPrev, inCurr, inNext, outCurr,
+				getSecretKey(), true);
+	}
+
 	private TransportKeys createTransportKeys() {
 		SecretKey inPrevTagKey = getSecretKey();
 		SecretKey inPrevHeaderKey = getSecretKey();

bramble-core/src/test/java/org/briarproject/bramble/db/JdbcDatabaseTest.java

@@ -2,6 +2,7 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContact;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.db.DbException;
@@ -20,10 +21,13 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.validation.MessageState;
 import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.transport.HandshakeKeySet;
+import org.briarproject.bramble.api.transport.HandshakeKeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
 import org.briarproject.bramble.api.transport.IncomingKeys;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.system.SystemClock;
 import org.briarproject.bramble.test.BrambleTestCase;
@@ -52,6 +56,7 @@ import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
 import static java.util.Collections.singletonMap;
 import static java.util.concurrent.TimeUnit.SECONDS;
+import static org.briarproject.bramble.api.contact.PendingContactState.FAILED;
 import static org.briarproject.bramble.api.db.Metadata.REMOVE;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
@@ -70,6 +75,7 @@ import static org.briarproject.bramble.test.TestUtils.getClientId;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
 import static org.briarproject.bramble.test.TestUtils.getLocalAuthor;
 import static org.briarproject.bramble.test.TestUtils.getMessage;
+import static org.briarproject.bramble.test.TestUtils.getPendingContact;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
 import static org.briarproject.bramble.test.TestUtils.getSecretKey;
 import static org.briarproject.bramble.test.TestUtils.getTestDirectory;
@@ -90,7 +96,6 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 	// All our transports use a maximum latency of 30 seconds
 	private static final int MAX_LATENCY = 30 * 1000;
 
-
 	private final SecretKey key = getSecretKey();
 	private final File testDir = getTestDirectory();
 	private final GroupId groupId;
@@ -103,7 +108,9 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 	private final MessageId messageId;
 	private final TransportId transportId;
 	private final ContactId contactId;
-	private final KeySetId keySetId, keySetId1;
+	private final TransportKeySetId keySetId, keySetId1;
+	private final HandshakeKeySetId handshakeKeySetId, handshakeKeySetId1;
+	private final PendingContact pendingContact;
 	private final Random random = new Random();
 
 	JdbcDatabaseTest() {
@@ -117,8 +124,11 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		messageId = message.getId();
 		transportId = getTransportId();
 		contactId = new ContactId(1);
-		keySetId = new KeySetId(1);
+		keySetId = new TransportKeySetId(1);
-		keySetId1 = new KeySetId(2);
+		keySetId1 = new TransportKeySetId(2);
+		handshakeKeySetId = new HandshakeKeySetId(1);
+		handshakeKeySetId1 = new HandshakeKeySetId(2);
+		pendingContact = getPendingContact();
 	}
 
 	protected abstract JdbcDatabase createDatabase(DatabaseConfig config,
@@ -653,10 +663,10 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 	@Test
 	public void testTransportKeys() throws Exception {
-		long rotationPeriod = 123, rotationPeriod1 = 234;
+		long timePeriod = 123, timePeriod1 = 234;
 		boolean active = random.nextBoolean();
-		TransportKeys keys = createTransportKeys(rotationPeriod, active);
+		TransportKeys keys = createTransportKeys(timePeriod, active);
-		TransportKeys keys1 = createTransportKeys(rotationPeriod1, active);
+		TransportKeys keys1 = createTransportKeys(timePeriod1, active);
 
 		Database<Connection> db = open(false);
 		Connection txn = db.startTransaction();
@@ -673,35 +683,38 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertEquals(keySetId1, db.addTransportKeys(txn, contactId, keys1));
 
 		// Retrieve the transport keys
-		Collection<KeySet> allKeys = db.getTransportKeys(txn, transportId);
+		Collection<TransportKeySet> allKeys =
+				db.getTransportKeys(txn, transportId);
 		assertEquals(2, allKeys.size());
-		for (KeySet ks : allKeys) {
+		for (TransportKeySet ks : allKeys) {
 			assertEquals(contactId, ks.getContactId());
 			if (ks.getKeySetId().equals(keySetId)) {
-				assertKeysEquals(keys, ks.getTransportKeys());
+				assertKeysEquals(keys, ks.getKeys());
 			} else {
 				assertEquals(keySetId1, ks.getKeySetId());
-				assertKeysEquals(keys1, ks.getTransportKeys());
+				assertKeysEquals(keys1, ks.getKeys());
 			}
 		}
 
 		// Rotate the transport keys
-		TransportKeys rotated = createTransportKeys(rotationPeriod + 1, active);
+		TransportKeys rotated = createTransportKeys(timePeriod + 1, active);
 		TransportKeys rotated1 =
-				createTransportKeys(rotationPeriod1 + 1, active);
+				createTransportKeys(timePeriod1 + 1, active);
-		db.updateTransportKeys(txn, new KeySet(keySetId, contactId, rotated));
+		db.updateTransportKeys(txn, new TransportKeySet(keySetId, contactId,
-		db.updateTransportKeys(txn, new KeySet(keySetId1, contactId, rotated1));
+				rotated));
+		db.updateTransportKeys(txn, new TransportKeySet(keySetId1, contactId,
+				rotated1));
 
 		// Retrieve the transport keys again
 		allKeys = db.getTransportKeys(txn, transportId);
 		assertEquals(2, allKeys.size());
-		for (KeySet ks : allKeys) {
+		for (TransportKeySet ks : allKeys) {
 			assertEquals(contactId, ks.getContactId());
 			if (ks.getKeySetId().equals(keySetId)) {
-				assertKeysEquals(rotated, ks.getTransportKeys());
+				assertKeysEquals(rotated, ks.getKeys());
 			} else {
 				assertEquals(keySetId1, ks.getKeySetId());
-				assertKeysEquals(rotated1, ks.getTransportKeys());
+				assertKeysEquals(rotated1, ks.getKeys());
 			}
 		}
 
@@ -716,7 +729,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 	private void assertKeysEquals(TransportKeys expected,
 			TransportKeys actual) {
 		assertEquals(expected.getTransportId(), actual.getTransportId());
-		assertEquals(expected.getRotationPeriod(), actual.getRotationPeriod());
+		assertEquals(expected.getTimePeriod(), actual.getTimePeriod());
 		assertKeysEquals(expected.getPreviousIncomingKeys(),
 				actual.getPreviousIncomingKeys());
 		assertKeysEquals(expected.getCurrentIncomingKeys(),
@@ -732,7 +745,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				actual.getTagKey().getBytes());
 		assertArrayEquals(expected.getHeaderKey().getBytes(),
 				actual.getHeaderKey().getBytes());
-		assertEquals(expected.getRotationPeriod(), actual.getRotationPeriod());
+		assertEquals(expected.getTimePeriod(), actual.getTimePeriod());
 		assertEquals(expected.getWindowBase(), actual.getWindowBase());
 		assertArrayEquals(expected.getWindowBitmap(), actual.getWindowBitmap());
 	}
@@ -742,15 +755,174 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				actual.getTagKey().getBytes());
 		assertArrayEquals(expected.getHeaderKey().getBytes(),
 				actual.getHeaderKey().getBytes());
-		assertEquals(expected.getRotationPeriod(), actual.getRotationPeriod());
+		assertEquals(expected.getTimePeriod(), actual.getTimePeriod());
 		assertEquals(expected.getStreamCounter(), actual.getStreamCounter());
 		assertEquals(expected.isActive(), actual.isActive());
 	}
 
+	@Test
+	public void testHandshakeKeys() throws Exception {
+		long timePeriod = 123, timePeriod1 = 234;
+		boolean alice = random.nextBoolean();
+		SecretKey rootKey = getSecretKey();
+		SecretKey rootKey1 = getSecretKey();
+		HandshakeKeys keys = createHandshakeKeys(timePeriod, rootKey, alice);
+		HandshakeKeys keys1 = createHandshakeKeys(timePeriod1, rootKey1, alice);
+
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Initially there should be no handshake keys in the database
+		assertEquals(emptyList(), db.getHandshakeKeys(txn, transportId));
+
+		// Add the contact, the transport and the handshake keys
+		db.addLocalAuthor(txn, localAuthor);
+		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
+				true, true));
+		db.addTransport(txn, transportId, 123);
+		assertEquals(handshakeKeySetId,
+				db.addHandshakeKeys(txn, contactId, keys));
+		assertEquals(handshakeKeySetId1,
+				db.addHandshakeKeys(txn, contactId, keys1));
+
+		// Retrieve the handshake keys
+		Collection<HandshakeKeySet> allKeys =
+				db.getHandshakeKeys(txn, transportId);
+		assertEquals(2, allKeys.size());
+		for (HandshakeKeySet ks : allKeys) {
+			assertEquals(contactId, ks.getContactId());
+			assertNull(ks.getPendingContactId());
+			if (ks.getKeySetId().equals(handshakeKeySetId)) {
+				assertKeysEquals(keys, ks.getKeys());
+			} else {
+				assertEquals(handshakeKeySetId1, ks.getKeySetId());
+				assertKeysEquals(keys1, ks.getKeys());
+			}
+		}
+
+		// Update the handshake keys
+		HandshakeKeys updated =
+				createHandshakeKeys(timePeriod + 1, rootKey, alice);
+		HandshakeKeys updated1 =
+				createHandshakeKeys(timePeriod1 + 1, rootKey1, alice);
+		db.updateHandshakeKeys(txn, new HandshakeKeySet(handshakeKeySetId,
+				contactId, updated));
+		db.updateHandshakeKeys(txn, new HandshakeKeySet(handshakeKeySetId1,
+				contactId, updated1));
+
+		// Retrieve the handshake keys again
+		allKeys = db.getHandshakeKeys(txn, transportId);
+		assertEquals(2, allKeys.size());
+		for (HandshakeKeySet ks : allKeys) {
+			assertEquals(contactId, ks.getContactId());
+			assertNull(ks.getPendingContactId());
+			if (ks.getKeySetId().equals(handshakeKeySetId)) {
+				assertKeysEquals(updated, ks.getKeys());
+			} else {
+				assertEquals(handshakeKeySetId1, ks.getKeySetId());
+				assertKeysEquals(updated1, ks.getKeys());
+			}
+		}
+
+		// Removing the contact should remove the handshake keys
+		db.removeContact(txn, contactId);
+		assertEquals(emptyList(), db.getHandshakeKeys(txn, transportId));
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
+	private void assertKeysEquals(HandshakeKeys expected,
+			HandshakeKeys actual) {
+		assertEquals(expected.getTransportId(), actual.getTransportId());
+		assertEquals(expected.getTimePeriod(), actual.getTimePeriod());
+		assertArrayEquals(expected.getRootKey().getBytes(),
+				actual.getRootKey().getBytes());
+		assertEquals(expected.isAlice(), actual.isAlice());
+		assertKeysEquals(expected.getPreviousIncomingKeys(),
+				actual.getPreviousIncomingKeys());
+		assertKeysEquals(expected.getCurrentIncomingKeys(),
+				actual.getCurrentIncomingKeys());
+		assertKeysEquals(expected.getNextIncomingKeys(),
+				actual.getNextIncomingKeys());
+		assertKeysEquals(expected.getCurrentOutgoingKeys(),
+				actual.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testHandshakeKeysForPendingContact() throws Exception {
+		long timePeriod = 123, timePeriod1 = 234;
+		boolean alice = random.nextBoolean();
+		SecretKey rootKey = getSecretKey();
+		SecretKey rootKey1 = getSecretKey();
+		HandshakeKeys keys = createHandshakeKeys(timePeriod, rootKey, alice);
+		HandshakeKeys keys1 = createHandshakeKeys(timePeriod1, rootKey1, alice);
+
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Initially there should be no handshake keys in the database
+		assertEquals(emptyList(), db.getHandshakeKeys(txn, transportId));
+
+		// Add the pending contact, the transport and the handshake keys
+		db.addPendingContact(txn, pendingContact);
+		db.addTransport(txn, transportId, 123);
+		assertEquals(handshakeKeySetId, db.addHandshakeKeys(txn,
+				pendingContact.getId(), keys));
+		assertEquals(handshakeKeySetId1, db.addHandshakeKeys(txn,
+				pendingContact.getId(), keys1));
+
+		// Retrieve the handshake keys
+		Collection<HandshakeKeySet> allKeys =
+				db.getHandshakeKeys(txn, transportId);
+		assertEquals(2, allKeys.size());
+		for (HandshakeKeySet ks : allKeys) {
+			assertNull(ks.getContactId());
+			assertEquals(pendingContact.getId(), ks.getPendingContactId());
+			if (ks.getKeySetId().equals(handshakeKeySetId)) {
+				assertKeysEquals(keys, ks.getKeys());
+			} else {
+				assertEquals(handshakeKeySetId1, ks.getKeySetId());
+				assertKeysEquals(keys1, ks.getKeys());
+			}
+		}
+
+		// Update the handshake keys
+		HandshakeKeys updated =
+				createHandshakeKeys(timePeriod + 1, rootKey, alice);
+		HandshakeKeys updated1 =
+				createHandshakeKeys(timePeriod1 + 1, rootKey1, alice);
+		db.updateHandshakeKeys(txn, new HandshakeKeySet(handshakeKeySetId,
+				pendingContact.getId(), updated));
+		db.updateHandshakeKeys(txn, new HandshakeKeySet(handshakeKeySetId1,
+				pendingContact.getId(), updated1));
+
+		// Retrieve the handshake keys again
+		allKeys = db.getHandshakeKeys(txn, transportId);
+		assertEquals(2, allKeys.size());
+		for (HandshakeKeySet ks : allKeys) {
+			assertNull(ks.getContactId());
+			assertEquals(pendingContact.getId(), ks.getPendingContactId());
+			if (ks.getKeySetId().equals(handshakeKeySetId)) {
+				assertKeysEquals(updated, ks.getKeys());
+			} else {
+				assertEquals(handshakeKeySetId1, ks.getKeySetId());
+				assertKeysEquals(updated1, ks.getKeys());
+			}
+		}
+
+		// Removing the pending contact should remove the handshake keys
+		db.removePendingContact(txn, pendingContact.getId());
+		assertEquals(emptyList(), db.getHandshakeKeys(txn, transportId));
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
 	@Test
 	public void testIncrementStreamCounter() throws Exception {
-		long rotationPeriod = 123;
+		long timePeriod = 123;
-		TransportKeys keys = createTransportKeys(rotationPeriod, true);
+		TransportKeys keys = createTransportKeys(timePeriod, true);
 		long streamCounter = keys.getCurrentOutgoingKeys().getStreamCounter();
 
 		Database<Connection> db = open(false);
@@ -766,15 +938,63 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		// Increment the stream counter twice and retrieve the transport keys
 		db.incrementStreamCounter(txn, transportId, keySetId);
 		db.incrementStreamCounter(txn, transportId, keySetId);
-		Collection<KeySet> newKeys = db.getTransportKeys(txn, transportId);
+		Collection<TransportKeySet> newKeys =
+				db.getTransportKeys(txn, transportId);
 		assertEquals(1, newKeys.size());
-		KeySet ks = newKeys.iterator().next();
+		TransportKeySet ks = newKeys.iterator().next();
 		assertEquals(keySetId, ks.getKeySetId());
 		assertEquals(contactId, ks.getContactId());
-		TransportKeys k = ks.getTransportKeys();
+		TransportKeys k = ks.getKeys();
 		assertEquals(transportId, k.getTransportId());
 		OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
-		assertEquals(rotationPeriod, outCurr.getRotationPeriod());
+		assertEquals(timePeriod, outCurr.getTimePeriod());
+		assertEquals(streamCounter + 2, outCurr.getStreamCounter());
+
+		// The rest of the keys should be unaffected
+		assertKeysEquals(keys.getPreviousIncomingKeys(),
+				k.getPreviousIncomingKeys());
+		assertKeysEquals(keys.getCurrentIncomingKeys(),
+				k.getCurrentIncomingKeys());
+		assertKeysEquals(keys.getNextIncomingKeys(), k.getNextIncomingKeys());
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
+	@Test
+	public void testIncrementStreamCounterForHandshakeKeys() throws Exception {
+		long timePeriod = 123;
+		SecretKey rootKey = getSecretKey();
+		boolean alice = random.nextBoolean();
+		HandshakeKeys keys = createHandshakeKeys(timePeriod, rootKey, alice);
+		long streamCounter = keys.getCurrentOutgoingKeys().getStreamCounter();
+
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Add the contact, transport and handshake keys
+		db.addLocalAuthor(txn, localAuthor);
+		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
+				true, true));
+		db.addTransport(txn, transportId, 123);
+		assertEquals(handshakeKeySetId,
+				db.addHandshakeKeys(txn, contactId, keys));
+
+		// Increment the stream counter twice and retrieve the handshake keys
+		db.incrementStreamCounter(txn, transportId, handshakeKeySetId);
+		db.incrementStreamCounter(txn, transportId, handshakeKeySetId);
+		Collection<HandshakeKeySet> newKeys =
+				db.getHandshakeKeys(txn, transportId);
+		assertEquals(1, newKeys.size());
+		HandshakeKeySet ks = newKeys.iterator().next();
+		assertEquals(handshakeKeySetId, ks.getKeySetId());
+		assertEquals(contactId, ks.getContactId());
+		HandshakeKeys k = ks.getKeys();
+		assertEquals(transportId, k.getTransportId());
+		assertArrayEquals(rootKey.getBytes(), k.getRootKey().getBytes());
+		assertEquals(alice, k.isAlice());
+		OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
+		assertEquals(timePeriod, outCurr.getTimePeriod());
 		assertEquals(streamCounter + 2, outCurr.getStreamCounter());
 
 		// The rest of the keys should be unaffected
@@ -791,8 +1011,8 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 	@Test
 	public void testSetReorderingWindow() throws Exception {
 		boolean active = random.nextBoolean();
-		long rotationPeriod = 123;
+		long timePeriod = 123;
-		TransportKeys keys = createTransportKeys(rotationPeriod, active);
+		TransportKeys keys = createTransportKeys(timePeriod, active);
 		long base = keys.getCurrentIncomingKeys().getWindowBase();
 		byte[] bitmap = keys.getCurrentIncomingKeys().getWindowBitmap();
 
@@ -808,17 +1028,68 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Update the reordering window and retrieve the transport keys
 		random.nextBytes(bitmap);
-		db.setReorderingWindow(txn, keySetId, transportId, rotationPeriod,
+		db.setReorderingWindow(txn, keySetId, transportId, timePeriod,
 				base + 1, bitmap);
-		Collection<KeySet> newKeys = db.getTransportKeys(txn, transportId);
+		Collection<TransportKeySet> newKeys =
+				db.getTransportKeys(txn, transportId);
 		assertEquals(1, newKeys.size());
-		KeySet ks = newKeys.iterator().next();
+		TransportKeySet ks = newKeys.iterator().next();
 		assertEquals(keySetId, ks.getKeySetId());
 		assertEquals(contactId, ks.getContactId());
-		TransportKeys k = ks.getTransportKeys();
+		TransportKeys k = ks.getKeys();
 		assertEquals(transportId, k.getTransportId());
 		IncomingKeys inCurr = k.getCurrentIncomingKeys();
-		assertEquals(rotationPeriod, inCurr.getRotationPeriod());
+		assertEquals(timePeriod, inCurr.getTimePeriod());
+		assertEquals(base + 1, inCurr.getWindowBase());
+		assertArrayEquals(bitmap, inCurr.getWindowBitmap());
+
+		// The rest of the keys should be unaffected
+		assertKeysEquals(keys.getPreviousIncomingKeys(),
+				k.getPreviousIncomingKeys());
+		assertKeysEquals(keys.getNextIncomingKeys(), k.getNextIncomingKeys());
+		assertKeysEquals(keys.getCurrentOutgoingKeys(),
+				k.getCurrentOutgoingKeys());
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
+	@Test
+	public void testSetReorderingWindowForHandshakeKeys() throws Exception {
+		long timePeriod = 123;
+		SecretKey rootKey = getSecretKey();
+		boolean alice = random.nextBoolean();
+		HandshakeKeys keys = createHandshakeKeys(timePeriod, rootKey, alice);
+		long base = keys.getCurrentIncomingKeys().getWindowBase();
+		byte[] bitmap = keys.getCurrentIncomingKeys().getWindowBitmap();
+
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Add the contact, transport and handshake keys
+		db.addLocalAuthor(txn, localAuthor);
+		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
+				true, true));
+		db.addTransport(txn, transportId, 123);
+		assertEquals(handshakeKeySetId,
+				db.addHandshakeKeys(txn, contactId, keys));
+
+		// Update the reordering window and retrieve the handshake keys
+		random.nextBytes(bitmap);
+		db.setReorderingWindow(txn, handshakeKeySetId, transportId, timePeriod,
+				base + 1, bitmap);
+		Collection<HandshakeKeySet> newKeys =
+				db.getHandshakeKeys(txn, transportId);
+		assertEquals(1, newKeys.size());
+		HandshakeKeySet ks = newKeys.iterator().next();
+		assertEquals(handshakeKeySetId, ks.getKeySetId());
+		assertEquals(contactId, ks.getContactId());
+		HandshakeKeys k = ks.getKeys();
+		assertEquals(transportId, k.getTransportId());
+		assertArrayEquals(rootKey.getBytes(), k.getRootKey().getBytes());
+		assertEquals(alice, k.isAlice());
+		IncomingKeys inCurr = k.getCurrentIncomingKeys();
+		assertEquals(timePeriod, inCurr.getTimePeriod());
 		assertEquals(base + 1, inCurr.getWindowBase());
 		assertArrayEquals(bitmap, inCurr.getWindowBitmap());
 
@@ -1965,6 +2236,39 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.close();
 	}
 
+	@Test
+	public void testPendingContacts() throws Exception {
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		assertEquals(emptyList(), db.getPendingContacts(txn));
+
+		db.addPendingContact(txn, pendingContact);
+		Collection<PendingContact> pendingContacts =
+				db.getPendingContacts(txn);
+		assertEquals(1, pendingContacts.size());
+		PendingContact retrieved = pendingContacts.iterator().next();
+		assertEquals(pendingContact.getId(), retrieved.getId());
+		assertEquals(pendingContact.getAlias(), retrieved.getAlias());
+		assertEquals(pendingContact.getState(), retrieved.getState());
+		assertEquals(pendingContact.getTimestamp(), retrieved.getTimestamp());
+
+		db.setPendingContactState(txn, pendingContact.getId(), FAILED);
+		pendingContacts = db.getPendingContacts(txn);
+		assertEquals(1, pendingContacts.size());
+		retrieved = pendingContacts.iterator().next();
+		assertEquals(pendingContact.getId(), retrieved.getId());
+		assertEquals(pendingContact.getAlias(), retrieved.getAlias());
+		assertEquals(FAILED, retrieved.getState());
+		assertEquals(pendingContact.getTimestamp(), retrieved.getTimestamp());
+
+		db.removePendingContact(txn, pendingContact.getId());
+		assertEquals(emptyList(), db.getPendingContacts(txn));
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
 	private Database<Connection> open(boolean resume) throws Exception {
 		return open(resume, new TestMessageFactory(), new SystemClock());
 	}
@@ -1978,27 +2282,48 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		return db;
 	}
 
-	private TransportKeys createTransportKeys(long rotationPeriod,
+	private TransportKeys createTransportKeys(long timePeriod, boolean active) {
-			boolean active) {
 		SecretKey inPrevTagKey = getSecretKey();
 		SecretKey inPrevHeaderKey = getSecretKey();
 		IncomingKeys inPrev = new IncomingKeys(inPrevTagKey, inPrevHeaderKey,
-				rotationPeriod - 1, 123, new byte[4]);
+				timePeriod - 1, 123, new byte[4]);
 		SecretKey inCurrTagKey = getSecretKey();
 		SecretKey inCurrHeaderKey = getSecretKey();
 		IncomingKeys inCurr = new IncomingKeys(inCurrTagKey, inCurrHeaderKey,
-				rotationPeriod, 234, new byte[4]);
+				timePeriod, 234, new byte[4]);
 		SecretKey inNextTagKey = getSecretKey();
 		SecretKey inNextHeaderKey = getSecretKey();
 		IncomingKeys inNext = new IncomingKeys(inNextTagKey, inNextHeaderKey,
-				rotationPeriod + 1, 345, new byte[4]);
+				timePeriod + 1, 345, new byte[4]);
 		SecretKey outCurrTagKey = getSecretKey();
 		SecretKey outCurrHeaderKey = getSecretKey();
 		OutgoingKeys outCurr = new OutgoingKeys(outCurrTagKey, outCurrHeaderKey,
-				rotationPeriod, 456, active);
+				timePeriod, 456, active);
 		return new TransportKeys(transportId, inPrev, inCurr, inNext, outCurr);
 	}
 
+	private HandshakeKeys createHandshakeKeys(long timePeriod,
+			SecretKey rootKey, boolean alice) {
+		SecretKey inPrevTagKey = getSecretKey();
+		SecretKey inPrevHeaderKey = getSecretKey();
+		IncomingKeys inPrev = new IncomingKeys(inPrevTagKey, inPrevHeaderKey,
+				timePeriod - 1, 123, new byte[4]);
+		SecretKey inCurrTagKey = getSecretKey();
+		SecretKey inCurrHeaderKey = getSecretKey();
+		IncomingKeys inCurr = new IncomingKeys(inCurrTagKey, inCurrHeaderKey,
+				timePeriod, 234, new byte[4]);
+		SecretKey inNextTagKey = getSecretKey();
+		SecretKey inNextHeaderKey = getSecretKey();
+		IncomingKeys inNext = new IncomingKeys(inNextTagKey, inNextHeaderKey,
+				timePeriod + 1, 345, new byte[4]);
+		SecretKey outCurrTagKey = getSecretKey();
+		SecretKey outCurrHeaderKey = getSecretKey();
+		OutgoingKeys outCurr = new OutgoingKeys(outCurrTagKey, outCurrHeaderKey,
+				timePeriod, 456, true);
+		return new HandshakeKeys(transportId, inPrev, inCurr, inNext, outCurr,
+				rootKey, alice);
+	}
+
 	@After
 	public void tearDown() {
 		deleteTestDirectory(testDir);

bramble-core/src/test/java/org/briarproject/bramble/keyagreement/KeyAgreementProtocolTest.java

@@ -17,7 +17,7 @@ import org.junit.Rule;
 import org.junit.Test;
 
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.COMMIT_LENGTH;
-import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.MASTER_SECRET_LABEL;
+import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.MASTER_KEY_LABEL;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.PROTOCOL_VERSION;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.SHARED_SECRET_LABEL;
 import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
@@ -74,7 +74,7 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 		Payload ourPayload = new Payload(aliceCommit, null);
 		KeyPair ourKeyPair = new KeyPair(ourPubKey, null);
 		SecretKey sharedSecret = getSecretKey();
-		SecretKey masterSecret = getSecretKey();
+		SecretKey masterKey = getSecretKey();
 
 		KeyAgreementProtocol protocol = new KeyAgreementProtocol(callbacks,
 				crypto, keyAgreementCrypto, payloadEncoder, transport,
@@ -134,13 +134,13 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 					true, false);
 			will(returnValue(bobConfirm));
 
-			// Alice computes master secret
+			// Alice derives master key
-			oneOf(crypto).deriveKey(MASTER_SECRET_LABEL, sharedSecret);
+			oneOf(crypto).deriveKey(MASTER_KEY_LABEL, sharedSecret);
-			will(returnValue(masterSecret));
+			will(returnValue(masterKey));
 		}});
 
 		// execute
-		assertThat(masterSecret, is(equalTo(protocol.perform())));
+		assertThat(masterKey, is(equalTo(protocol.perform())));
 	}
 
 	@Test
@@ -150,7 +150,7 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 		Payload ourPayload = new Payload(bobCommit, null);
 		KeyPair ourKeyPair = new KeyPair(ourPubKey, null);
 		SecretKey sharedSecret = getSecretKey();
-		SecretKey masterSecret = getSecretKey();
+		SecretKey masterKey = getSecretKey();
 
 		KeyAgreementProtocol protocol = new KeyAgreementProtocol(callbacks,
 				crypto, keyAgreementCrypto, payloadEncoder, transport,
@@ -209,13 +209,13 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 			will(returnValue(bobConfirm));
 			oneOf(transport).sendConfirm(bobConfirm);
 
-			// Bob computes master secret
+			// Bob derives master key
-			oneOf(crypto).deriveKey(MASTER_SECRET_LABEL, sharedSecret);
+			oneOf(crypto).deriveKey(MASTER_KEY_LABEL, sharedSecret);
-			will(returnValue(masterSecret));
+			will(returnValue(masterKey));
 		}});
 
 		// execute
-		assertThat(masterSecret, is(equalTo(protocol.perform())));
+		assertThat(masterKey, is(equalTo(protocol.perform())));
 	}
 
 	@Test(expected = AbortException.class)
@@ -373,8 +373,8 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 			// Alice aborts
 			oneOf(transport).sendAbort(false);
 
-			// Alice never computes master secret
+			// Alice never derives master key
-			never(crypto).deriveKey(MASTER_SECRET_LABEL, sharedSecret);
+			never(crypto).deriveKey(MASTER_KEY_LABEL, sharedSecret);
 		}});
 
 		// execute

bramble-core/src/test/java/org/briarproject/bramble/transport/KeyManagerImplTest.java

@@ -12,8 +12,8 @@ import org.briarproject.bramble.api.identity.AuthorId;
 import org.briarproject.bramble.api.plugin.PluginConfig;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.DbExpectations;
 import org.jmock.Expectations;
@@ -51,7 +51,7 @@ public class KeyManagerImplTest extends BrambleMockTestCase {
 	private final Transaction txn = new Transaction(null, false);
 	private final ContactId contactId = new ContactId(123);
 	private final ContactId inactiveContactId = new ContactId(234);
-	private final KeySetId keySetId = new KeySetId(345);
+	private final TransportKeySetId keySetId = new TransportKeySetId(345);
 	private final TransportId transportId = getTransportId();
 	private final TransportId unknownTransportId = getTransportId();
 	private final StreamContext streamContext =
@@ -113,8 +113,8 @@ public class KeyManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(keySetId));
 		}});
 
-		Map<TransportId, KeySetId> ids = keyManager.addContact(txn, contactId,
+		Map<TransportId, TransportKeySetId> ids = keyManager.addContact(txn,
-				secretKey, timestamp, alice, active);
+				contactId, secretKey, timestamp, alice, active);
 		assertEquals(singletonMap(transportId, keySetId), ids);
 	}
 

bramble-core/src/test/java/org/briarproject/bramble/transport/TransportKeyManagerImplTest.java

@@ -8,10 +8,10 @@ import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.transport.IncomingKeys;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
 import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.DbExpectations;
@@ -57,31 +57,31 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 
 	private final TransportId transportId = getTransportId();
 	private final long maxLatency = 30 * 1000; // 30 seconds
-	private final long rotationPeriodLength = maxLatency + MAX_CLOCK_DIFFERENCE;
+	private final long timePeriodLength = maxLatency + MAX_CLOCK_DIFFERENCE;
 	private final ContactId contactId = new ContactId(123);
 	private final ContactId contactId1 = new ContactId(234);
-	private final KeySetId keySetId = new KeySetId(345);
+	private final TransportKeySetId keySetId = new TransportKeySetId(345);
-	private final KeySetId keySetId1 = new KeySetId(456);
+	private final TransportKeySetId keySetId1 = new TransportKeySetId(456);
 	private final SecretKey tagKey = TestUtils.getSecretKey();
 	private final SecretKey headerKey = TestUtils.getSecretKey();
-	private final SecretKey masterKey = TestUtils.getSecretKey();
+	private final SecretKey rootKey = TestUtils.getSecretKey();
 	private final Random random = new Random();
 
 	@Test
 	public void testKeysAreRotatedAtStartup() throws Exception {
 		TransportKeys shouldRotate = createTransportKeys(900, 0, true);
 		TransportKeys shouldNotRotate = createTransportKeys(1000, 0, true);
-		Collection<KeySet> loaded = asList(
+		Collection<TransportKeySet> loaded = asList(
-				new KeySet(keySetId, contactId, shouldRotate),
+				new TransportKeySet(keySetId, contactId, shouldRotate),
-				new KeySet(keySetId1, contactId1, shouldNotRotate)
+				new TransportKeySet(keySetId1, contactId1, shouldNotRotate)
 		);
 		TransportKeys rotated = createTransportKeys(1000, 0, true);
 		Transaction txn = new Transaction(null, false);
 
 		context.checking(new Expectations() {{
-			// Get the current time (1 ms after start of rotation period 1000)
+			// Get the current time (1 ms after start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000 + 1));
+			will(returnValue(timePeriodLength * 1000 + 1));
 			// Load the transport keys
 			oneOf(db).getTransportKeys(txn, transportId);
 			will(returnValue(loaded));
@@ -98,11 +98,11 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 				will(new EncodeTagAction());
 			}
 			// Save the keys that were rotated
-			oneOf(db).updateTransportKeys(txn,
+			oneOf(db).updateTransportKeys(txn, singletonList(
-					singletonList(new KeySet(keySetId, contactId, rotated)));
+					new TransportKeySet(keySetId, contactId, rotated)));
-			// Schedule key rotation at the start of the next rotation period
+			// Schedule key rotation at the start of the next time period
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(rotationPeriodLength - 1), with(MILLISECONDS));
+					with(timePeriodLength - 1), with(MILLISECONDS));
 		}});
 
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
@@ -120,12 +120,12 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		Transaction txn = new Transaction(null, false);
 
 		context.checking(new Expectations() {{
-			oneOf(transportCrypto).deriveTransportKeys(transportId, masterKey,
+			oneOf(transportCrypto).deriveTransportKeys(transportId, rootKey,
 					999, alice, true);
 			will(returnValue(transportKeys));
-			// Get the current time (1 ms after start of rotation period 1000)
+			// Get the current time (1 ms after start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000 + 1));
+			will(returnValue(timePeriodLength * 1000 + 1));
 			// Rotate the transport keys
 			oneOf(transportCrypto).rotateTransportKeys(transportKeys, 1000);
 			will(returnValue(rotated));
@@ -144,10 +144,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is 1 ms before the start of rotation period 1000
+		// The timestamp is 1 ms before the start of time period 1000
-		long timestamp = rotationPeriodLength * 1000 - 1;
+		long timestamp = timePeriodLength * 1000 - 1;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, true));
+				rootKey, timestamp, alice, true));
 		assertTrue(transportKeyManager.canSendOutgoingStreams(contactId));
 	}
 
@@ -177,10 +177,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
+		// The timestamp is at the start of time period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, true));
+				rootKey, timestamp, alice, true));
 		assertFalse(transportKeyManager.canSendOutgoingStreams(contactId));
 		assertNull(transportKeyManager.getStreamContext(txn, contactId));
 	}
@@ -203,10 +203,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
+		// The timestamp is at the start of time period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, true));
+				rootKey, timestamp, alice, true));
 		// The first request should return a stream context
 		assertTrue(transportKeyManager.canSendOutgoingStreams(contactId));
 		StreamContext ctx = transportKeyManager.getStreamContext(txn,
@@ -235,10 +235,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
+		// The timestamp is at the start of time period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, active));
+				rootKey, timestamp, alice, active));
 		assertEquals(active,
 				transportKeyManager.canSendOutgoingStreams(contactId));
 		// The tag should not be recognised
@@ -256,12 +256,12 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		List<byte[]> tags = new ArrayList<>();
 
 		context.checking(new Expectations() {{
-			oneOf(transportCrypto).deriveTransportKeys(transportId, masterKey,
+			oneOf(transportCrypto).deriveTransportKeys(transportId, rootKey,
 					1000, alice, true);
 			will(returnValue(transportKeys));
-			// Get the current time (the start of rotation period 1000)
+			// Get the current time (the start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000));
+			will(returnValue(timePeriodLength * 1000));
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(transportCrypto).encodeTag(
@@ -280,7 +280,7 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 					with(tagKey), with(PROTOCOL_VERSION),
 					with((long) REORDERING_WINDOW_SIZE));
 			will(new EncodeTagAction(tags));
-			// Save the reordering window (previous rotation period, base 1)
+			// Save the reordering window (previous time period, base 1)
 			oneOf(db).setReorderingWindow(txn, keySetId, transportId, 999,
 					1, new byte[REORDERING_WINDOW_SIZE / 8]);
 		}});
@@ -288,12 +288,12 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
+		// The timestamp is at the start of time period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, true));
+				rootKey, timestamp, alice, true));
 		assertTrue(transportKeyManager.canSendOutgoingStreams(contactId));
-		// Use the first tag (previous rotation period, stream number 0)
+		// Use the first tag (previous time period, stream number 0)
 		assertEquals(REORDERING_WINDOW_SIZE * 3, tags.size());
 		byte[] tag = tags.get(0);
 		// The first request should return a stream context
@@ -313,16 +313,16 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testKeysAreRotatedToCurrentPeriod() throws Exception {
 		TransportKeys transportKeys = createTransportKeys(1000, 0, true);
-		Collection<KeySet> loaded =
+		Collection<TransportKeySet> loaded = singletonList(
-				singletonList(new KeySet(keySetId, contactId, transportKeys));
+				new TransportKeySet(keySetId, contactId, transportKeys));
 		TransportKeys rotated = createTransportKeys(1001, 0, true);
 		Transaction txn = new Transaction(null, false);
 		Transaction txn1 = new Transaction(null, false);
 
 		context.checking(new DbExpectations() {{
-			// Get the current time (the start of rotation period 1000)
+			// Get the current time (the start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000));
+			will(returnValue(timePeriodLength * 1000));
 			// Load the transport keys
 			oneOf(db).getTransportKeys(txn, transportId);
 			will(returnValue(loaded));
@@ -336,17 +336,17 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 						with(PROTOCOL_VERSION), with(i));
 				will(new EncodeTagAction());
 			}
-			// Schedule key rotation at the start of the next rotation period
+			// Schedule key rotation at the start of the next time period
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(rotationPeriodLength), with(MILLISECONDS));
+					with(timePeriodLength), with(MILLISECONDS));
 			will(new RunAction());
 			oneOf(dbExecutor).execute(with(any(Runnable.class)));
 			will(new RunAction());
 			// Start a transaction for key rotation
 			oneOf(db).transaction(with(false), withDbRunnable(txn1));
-			// Get the current time (the start of rotation period 1001)
+			// Get the current time (the start of time period 1001)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1001));
+			will(returnValue(timePeriodLength * 1001));
 			// Rotate the transport keys
 			oneOf(transportCrypto).rotateTransportKeys(
 					with(any(TransportKeys.class)), with(1001L));
@@ -359,11 +359,11 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 				will(new EncodeTagAction());
 			}
 			// Save the keys that were rotated
-			oneOf(db).updateTransportKeys(txn1,
+			oneOf(db).updateTransportKeys(txn1, singletonList(
-					singletonList(new KeySet(keySetId, contactId, rotated)));
+					new TransportKeySet(keySetId, contactId, rotated)));
-			// Schedule key rotation at the start of the next rotation period
+			// Schedule key rotation at the start of the next time period
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(rotationPeriodLength), with(MILLISECONDS));
+					with(timePeriodLength), with(MILLISECONDS));
 		}});
 
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
@@ -391,10 +391,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
+		// The timestamp is at the start of time period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, false));
+				rootKey, timestamp, alice, false));
 		// The keys are inactive so no stream context should be returned
 		assertFalse(transportKeyManager.canSendOutgoingStreams(contactId));
 		assertNull(transportKeyManager.getStreamContext(txn, contactId));
@@ -421,12 +421,12 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		List<byte[]> tags = new ArrayList<>();
 
 		context.checking(new Expectations() {{
-			oneOf(transportCrypto).deriveTransportKeys(transportId, masterKey,
+			oneOf(transportCrypto).deriveTransportKeys(transportId, rootKey,
 					1000, alice, false);
 			will(returnValue(transportKeys));
-			// Get the current time (the start of rotation period 1000)
+			// Get the current time (the start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000));
+			will(returnValue(timePeriodLength * 1000));
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(transportCrypto).encodeTag(
@@ -445,7 +445,7 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 					with(tagKey), with(PROTOCOL_VERSION),
 					with((long) REORDERING_WINDOW_SIZE));
 			will(new EncodeTagAction(tags));
-			// Save the reordering window (previous rotation period, base 1)
+			// Save the reordering window (previous time period, base 1)
 			oneOf(db).setReorderingWindow(txn, keySetId, transportId, 999,
 					1, new byte[REORDERING_WINDOW_SIZE / 8]);
 			// Activate the keys
@@ -457,10 +457,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
+		// The timestamp is at the start of time period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, false));
+				rootKey, timestamp, alice, false));
 		// The keys are inactive so no stream context should be returned
 		assertFalse(transportKeyManager.canSendOutgoingStreams(contactId));
 		assertNull(transportKeyManager.getStreamContext(txn, contactId));
@@ -488,12 +488,12 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 	private void expectAddContactNoRotation(boolean alice, boolean active,
 			TransportKeys transportKeys, Transaction txn) throws Exception {
 		context.checking(new Expectations() {{
-			oneOf(transportCrypto).deriveTransportKeys(transportId, masterKey,
+			oneOf(transportCrypto).deriveTransportKeys(transportId, rootKey,
 					1000, alice, active);
 			will(returnValue(transportKeys));
-			// Get the current time (the start of rotation period 1000)
+			// Get the current time (the start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000));
+			will(returnValue(timePeriodLength * 1000));
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(transportCrypto).encodeTag(
@@ -510,16 +510,16 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		}});
 	}
 
-	private TransportKeys createTransportKeys(long rotationPeriod,
+	private TransportKeys createTransportKeys(long timePeriod,
 			long streamCounter, boolean active) {
 		IncomingKeys inPrev = new IncomingKeys(tagKey, headerKey,
-				rotationPeriod - 1);
+				timePeriod - 1);
 		IncomingKeys inCurr = new IncomingKeys(tagKey, headerKey,
-				rotationPeriod);
+				timePeriod);
 		IncomingKeys inNext = new IncomingKeys(tagKey, headerKey,
-				rotationPeriod + 1);
+				timePeriod + 1);
 		OutgoingKeys outCurr = new OutgoingKeys(tagKey, headerKey,
-				rotationPeriod, streamCounter, active);
+				timePeriod, streamCounter, active);
 		return new TransportKeys(transportId, inPrev, inCurr, inNext, outCurr);
 	}
 

briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeProtocolEngine.java

@@ -23,7 +23,7 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.briar.api.client.MessageTracker;
 import org.briarproject.briar.api.client.ProtocolStateException;
 import org.briarproject.briar.api.client.SessionId;
@@ -430,7 +430,7 @@ class IntroduceeProtocolEngine
 				s.getRemote().acceptTimestamp);
 		if (timestamp == -1) throw new AssertionError();
 
-		Map<TransportId, KeySetId> keys = null;
+		Map<TransportId, TransportKeySetId> keys = null;
 		try {
 			contactManager
 					.addContact(txn, s.getRemote().author, localAuthor.getId(),

briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeSession.java

@@ -8,7 +8,7 @@ import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.introduction.Role;
 
@@ -17,9 +17,9 @@ import java.util.Map;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
+import static org.briarproject.briar.api.introduction.Role.INTRODUCEE;
 import static org.briarproject.briar.introduction.IntroduceeState.AWAIT_ACTIVATE;
 import static org.briarproject.briar.introduction.IntroduceeState.START;
-import static org.briarproject.briar.api.introduction.Role.INTRODUCEE;
 
 @Immutable
 @NotNullByDefault
@@ -33,12 +33,12 @@ class IntroduceeSession extends Session<IntroduceeState>
 	@Nullable
 	private final byte[] masterKey;
 	@Nullable
-	private final Map<TransportId, KeySetId> transportKeys;
+	private final Map<TransportId, TransportKeySetId> transportKeys;
 
 	IntroduceeSession(SessionId sessionId, IntroduceeState state,
 			long requestTimestamp, GroupId contactGroupId, Author introducer,
 			Local local, Remote remote, @Nullable byte[] masterKey,
-			@Nullable Map<TransportId, KeySetId> transportKeys) {
+			@Nullable Map<TransportId, TransportKeySetId> transportKeys) {
 		super(sessionId, state, requestTimestamp);
 		this.contactGroupId = contactGroupId;
 		this.introducer = introducer;
@@ -113,7 +113,8 @@ class IntroduceeSession extends Session<IntroduceeState>
 	}
 
 	static IntroduceeSession awaitActivate(IntroduceeSession s, AuthMessage m,
-			Message sent, @Nullable Map<TransportId, KeySetId> transportKeys) {
+			Message sent,
+			@Nullable Map<TransportId, TransportKeySetId> transportKeys) {
 		Local local = new Local(s.local, sent.getId(), sent.getTimestamp());
 		Remote remote = new Remote(s.remote, m.getMessageId());
 		return new IntroduceeSession(s.getSessionId(), AWAIT_ACTIVATE,
@@ -180,7 +181,7 @@ class IntroduceeSession extends Session<IntroduceeState>
 	}
 
 	@Nullable
-	Map<TransportId, KeySetId> getTransportKeys() {
+	Map<TransportId, TransportKeySetId> getTransportKeys() {
 		return transportKeys;
 	}
 

briar-core/src/main/java/org/briarproject/briar/introduction/IntroductionCrypto.java

@@ -41,7 +41,8 @@ interface IntroductionCrypto {
 	/**
 	 * Derives a MAC key from the session's master key for Alice or Bob.
 	 *
-	 * @param masterKey The key returned by {@link #deriveMasterKey(IntroduceeSession)}
+	 * @param masterKey The key returned by
+	 * {@link #deriveMasterKey(IntroduceeSession)}
 	 * @param alice true for Alice's MAC key, false for Bob's
 	 * @return The MAC key
 	 */

briar-core/src/main/java/org/briarproject/briar/introduction/SessionEncoderImpl.java

@@ -6,7 +6,7 @@ import org.briarproject.bramble.api.data.BdfEntry;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.briar.introduction.IntroduceeSession.Common;
 import org.briarproject.briar.introduction.IntroduceeSession.Local;
 import org.briarproject.briar.introduction.IntroduceeSession.Remote;
@@ -143,10 +143,10 @@ class SessionEncoderImpl implements SessionEncoder {
 
 	@Nullable
 	private BdfDictionary encodeTransportKeys(
-			@Nullable Map<TransportId, KeySetId> keys) {
+			@Nullable Map<TransportId, TransportKeySetId> keys) {
 		if (keys == null) return null;
 		BdfDictionary d = new BdfDictionary();
-		for (Map.Entry<TransportId, KeySetId> e : keys.entrySet()) {
+		for (Map.Entry<TransportId, TransportKeySetId> e : keys.entrySet()) {
 			d.put(e.getKey().getString(), e.getValue().getInt());
 		}
 		return d;

briar-core/src/main/java/org/briarproject/briar/introduction/SessionParserImpl.java

@@ -10,7 +10,7 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.introduction.Role;
 import org.briarproject.briar.introduction.IntroduceeSession.Local;
@@ -110,7 +110,7 @@ class SessionParserImpl implements SessionParser {
 		Local local = parseLocal(d.getDictionary(SESSION_KEY_LOCAL));
 		Remote remote = parseRemote(d.getDictionary(SESSION_KEY_REMOTE));
 		byte[] masterKey = d.getOptionalRaw(SESSION_KEY_MASTER_KEY);
-		Map<TransportId, KeySetId> transportKeys = parseTransportKeys(
+		Map<TransportId, TransportKeySetId> transportKeys = parseTransportKeys(
 				d.getOptionalDictionary(SESSION_KEY_TRANSPORT_KEYS));
 		return new IntroduceeSession(sessionId, state, requestTimestamp,
 				introducerGroupId, introducer, local, remote,
@@ -184,14 +184,13 @@ class SessionParserImpl implements SessionParser {
 	}
 
 	@Nullable
-	private Map<TransportId, KeySetId> parseTransportKeys(
+	private Map<TransportId, TransportKeySetId> parseTransportKeys(
 			@Nullable BdfDictionary d) throws FormatException {
 		if (d == null) return null;
-		Map<TransportId, KeySetId> map = new HashMap<>(d.size());
+		Map<TransportId, TransportKeySetId> map = new HashMap<>(d.size());
 		for (String key : d.keySet()) {
 			map.put(new TransportId(key),
-					new KeySetId(d.getLong(key).intValue())
+					new TransportKeySetId(d.getLong(key).intValue()));
-			);
 		}
 		return map;
 	}

briar-core/src/test/java/org/briarproject/briar/introduction/SessionEncoderParserIntegrationTest.java

@@ -10,7 +10,7 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.introduction.IntroducerSession.Introducee;
@@ -75,7 +75,8 @@ public class SessionEncoderParserIntegrationTest extends BrambleTestCase {
 			getTransportPropertiesMap(3);
 	private final Map<TransportId, TransportProperties>
 			remoteTransportProperties = getTransportPropertiesMap(3);
-	private final Map<TransportId, KeySetId> transportKeys = new HashMap<>();
+	private final Map<TransportId, TransportKeySetId> transportKeys =
+			new HashMap<>();
 	private final byte[] localMacKey = getRandomBytes(SecretKey.LENGTH);
 	private final byte[] remoteMacKey = getRandomBytes(SecretKey.LENGTH);
 
@@ -88,9 +89,9 @@ public class SessionEncoderParserIntegrationTest extends BrambleTestCase {
 		sessionParser = new SessionParserImpl(clientHelper);
 		author1 = getRealAuthor(authorFactory);
 		author2 = getRealAuthor(authorFactory);
-		transportKeys.put(getTransportId(), new KeySetId(1));
+		transportKeys.put(getTransportId(), new TransportKeySetId(1));
-		transportKeys.put(getTransportId(), new KeySetId(2));
+		transportKeys.put(getTransportId(), new TransportKeySetId(2));
-		transportKeys.put(getTransportId(), new KeySetId(3));
+		transportKeys.put(getTransportId(), new TransportKeySetId(3));
 	}
 
 	@Test

briar-core/src/test/java/org/briarproject/briar/messaging/SimplexMessagingIntegrationTest.java

@@ -56,7 +56,7 @@ public class SimplexMessagingIntegrationTest extends BriarTestCase {
 	private final File testDir = getTestDirectory();
 	private final File aliceDir = new File(testDir, "alice");
 	private final File bobDir = new File(testDir, "bob");
-	private final SecretKey master = getSecretKey();
+	private final SecretKey rootKey = getSecretKey();
 	private final long timestamp = System.currentTimeMillis();
 
 	private SimplexMessagingIntegrationTestComponent alice, bob;
@@ -110,7 +110,7 @@ public class SimplexMessagingIntegrationTest extends BriarTestCase {
 		lifecycleManager.waitForStartup();
 		// Add the other user as a contact
 		ContactManager contactManager = device.getContactManager();
-		return contactManager.addContact(remote, local.getId(), master,
+		return contactManager.addContact(remote, local.getId(), rootKey,
 				timestamp, alice, true, true);
 	}