diff --git a/.idea/codeStyles/Project.xml b/.idea/codeStyles/Project.xml
index 7b9dcd72e..3d081536f 100644
--- a/.idea/codeStyles/Project.xml
+++ b/.idea/codeStyles/Project.xml
@@ -31,15 +31,6 @@
       <option name="PACKAGES_TO_USE_STAR_IMPORTS">
         <value />
       </option>
-      <option name="PACKAGES_IMPORT_LAYOUT">
-        <value>
-          <package name="" alias="false" withSubpackages="true" />
-          <package name="java" alias="false" withSubpackages="true" />
-          <package name="javax" alias="false" withSubpackages="true" />
-          <package name="kotlin" alias="false" withSubpackages="true" />
-          <package name="" alias="true" withSubpackages="true" />
-        </value>
-      </option>
       <option name="NAME_COUNT_TO_USE_STAR_IMPORT" value="2147483647" />
       <option name="NAME_COUNT_TO_USE_STAR_IMPORT_FOR_MEMBERS" value="2147483647" />
       <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
diff --git a/bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseModule.java b/bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseModule.java
index 915ce7f16..b047f0d55 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseModule.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseModule.java
@@ -6,7 +6,6 @@ import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.lifecycle.ShutdownManager;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 
 import java.sql.Connection;
@@ -22,9 +21,8 @@ public class DatabaseModule {
 
 	@Provides
 	@Singleton
-	Database<Connection> provideDatabase(DatabaseConfig config,
-			MessageFactory messageFactory, Clock clock) {
-		return new H2Database(config, messageFactory, clock);
+	Database<Connection> provideDatabase(DatabaseConfig config, Clock clock) {
+		return new H2Database(config, clock);
 	}
 
 	@Provides
diff --git a/bramble-core/src/main/java/org/briarproject/bramble/db/H2Database.java b/bramble-core/src/main/java/org/briarproject/bramble/db/H2Database.java
index fe59c35a1..82af38e8b 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/db/H2Database.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/db/H2Database.java
@@ -6,7 +6,6 @@ import org.briarproject.bramble.api.db.DbClosedException;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.util.StringUtils;
 
@@ -51,9 +50,8 @@ class H2Database extends JdbcDatabase {
 	private volatile SecretKey key = null;
 
 	@Inject
-	H2Database(DatabaseConfig config, MessageFactory messageFactory,
-			Clock clock) {
-		super(dbTypes, messageFactory, clock);
+	H2Database(DatabaseConfig config, Clock clock) {
+		super(dbTypes, clock);
 		this.config = config;
 		File dir = config.getDatabaseDirectory();
 		String path = new File(dir, "db").getAbsolutePath();
diff --git a/bramble-core/src/main/java/org/briarproject/bramble/db/HyperSqlDatabase.java b/bramble-core/src/main/java/org/briarproject/bramble/db/HyperSqlDatabase.java
index aad359498..a7da569ff 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/db/HyperSqlDatabase.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/db/HyperSqlDatabase.java
@@ -6,7 +6,6 @@ import org.briarproject.bramble.api.db.DbClosedException;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.util.StringUtils;
 
@@ -51,9 +50,8 @@ class HyperSqlDatabase extends JdbcDatabase {
 	private volatile SecretKey key = null;
 
 	@Inject
-	HyperSqlDatabase(DatabaseConfig config, MessageFactory messageFactory,
-			Clock clock) {
-		super(dbTypes, messageFactory, clock);
+	HyperSqlDatabase(DatabaseConfig config, Clock clock) {
+		super(dbTypes, clock);
 		this.config = config;
 		File dir = config.getDatabaseDirectory();
 		String path = new File(dir, "db").getAbsolutePath();
diff --git a/bramble-core/src/main/java/org/briarproject/bramble/db/JdbcDatabase.java b/bramble-core/src/main/java/org/briarproject/bramble/db/JdbcDatabase.java
index c56b48e8d..8b8535449 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/db/JdbcDatabase.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/db/JdbcDatabase.java
@@ -30,7 +30,6 @@ import org.briarproject.bramble.api.sync.Group;
 import org.briarproject.bramble.api.sync.Group.Visibility;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.validation.MessageState;
@@ -76,7 +75,6 @@ import static org.briarproject.bramble.api.db.Metadata.REMOVE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
-import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
 import static org.briarproject.bramble.api.sync.validation.MessageState.DELIVERED;
 import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
 import static org.briarproject.bramble.api.sync.validation.MessageState.UNKNOWN;
@@ -98,7 +96,7 @@ import static org.briarproject.bramble.util.LogUtils.now;
 abstract class JdbcDatabase implements Database<Connection> {
 
 	// Package access for testing
-	static final int CODE_SCHEMA_VERSION = 47;
+	static final int CODE_SCHEMA_VERSION = 48;
 
 	// Time period offsets for incoming transport keys
 	private static final int OFFSET_PREV = -1;
@@ -181,7 +179,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " shared BOOLEAN NOT NULL,"
 					+ " temporary BOOLEAN NOT NULL,"
 					+ " length INT NOT NULL,"
-					+ " raw BLOB," // Null if message has been deleted
+					+ " deleted BOOLEAN NOT NULL,"
+					+ " blockCount INT NOT NULL,"
 					+ " PRIMARY KEY (messageId),"
 					+ " FOREIGN KEY (groupId)"
 					+ " REFERENCES groups (groupId)"
@@ -227,6 +226,17 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " REFERENCES contacts (contactId)"
 					+ " ON DELETE CASCADE)";
 
+	private static final String CREATE_BLOCKS =
+			"CREATE TABLE blocks"
+					+ " (messageId _HASH NOT NULL,"
+					+ " blockNumber INT NOT NULL,"
+					+ " blockLength INT NOT NULL,"
+					+ " data BLOB," // Null if message has been deleted
+					+ " PRIMARY KEY (messageId, blockNumber),"
+					+ " FOREIGN KEY (messageId)"
+					+ " REFERENCES messages (messageId)"
+					+ " ON DELETE CASCADE)";
+
 	private static final String CREATE_STATUSES =
 			"CREATE TABLE statuses"
 					+ " (messageId _HASH NOT NULL,"
@@ -339,7 +349,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private static final Logger LOG =
 			getLogger(JdbcDatabase.class.getName());
 
-	private final MessageFactory messageFactory;
 	private final Clock clock;
 	private final DatabaseTypes dbTypes;
 
@@ -359,10 +368,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	protected abstract void compactAndClose() throws DbException;
 
-	JdbcDatabase(DatabaseTypes databaseTypes, MessageFactory messageFactory,
-			Clock clock) {
+	JdbcDatabase(DatabaseTypes databaseTypes, Clock clock) {
 		this.dbTypes = databaseTypes;
-		this.messageFactory = messageFactory;
 		this.clock = clock;
 	}
 
@@ -463,7 +470,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 				new Migration43_44(dbTypes),
 				new Migration44_45(),
 				new Migration45_46(),
-				new Migration46_47(dbTypes)
+				new Migration46_47(dbTypes),
+				new Migration47_48(dbTypes)
 		);
 	}
 
@@ -509,6 +517,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_MESSAGE_METADATA));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_MESSAGE_DEPENDENCIES));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_OFFERS));
+			s.executeUpdate(dbTypes.replaceTypes(CREATE_BLOCKS));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_STATUSES));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_TRANSPORTS));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_PENDING_CONTACTS));
@@ -726,7 +735,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		ResultSet rs = null;
 		try {
 			String sql = "SELECT messageId, timestamp, state, shared,"
-					+ " length, raw IS NULL"
+					+ " length, deleted"
 					+ " FROM messages"
 					+ " WHERE groupId = ?";
 			ps = txn.prepareStatement(sql);
@@ -788,8 +797,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		try {
 			String sql = "INSERT INTO messages (messageId, groupId, timestamp,"
-					+ " state, shared, temporary, length, raw)"
-					+ " VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
+					+ " state, shared, temporary, length, deleted, blockCount)"
+					+ " VALUES (?, ?, ?, ?, ?, ?, ?, FALSE, 1)";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getId().getBytes());
 			ps.setBytes(2, m.getGroupId().getBytes());
@@ -797,12 +806,20 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(4, state.getValue());
 			ps.setBoolean(5, shared);
 			ps.setBoolean(6, temporary);
-			byte[] raw = messageFactory.getRawMessage(m);
-			ps.setInt(7, raw.length);
-			ps.setBytes(8, raw);
+			ps.setInt(7, m.getRawLength());
 			int affected = ps.executeUpdate();
 			if (affected != 1) throw new DbStateException();
 			ps.close();
+			sql = "INSERT INTO blocks (messageId, blockNumber, blockLength,"
+					+ " data)"
+					+ " VALUES (?, 0, ?, ?)";
+			ps = txn.prepareStatement(sql);
+			ps.setBytes(1, m.getId().getBytes());
+			ps.setInt(2, m.getBody().length);
+			ps.setBytes(3, m.getBody());
+			affected = ps.executeUpdate();
+			if (affected != 1) throw new DbStateException();
+			ps.close();
 			// Create a status row for each contact that can see the group
 			Map<ContactId, Boolean> visibility =
 					getGroupVisibility(txn, m.getGroupId());
@@ -811,7 +828,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 				boolean offered = removeOfferedMessage(txn, c, m.getId());
 				boolean seen = offered || c.equals(sender);
 				addStatus(txn, m.getId(), c, m.getGroupId(), m.getTimestamp(),
-						raw.length, state, e.getValue(), shared, false, seen);
+						m.getRawLength(), state, e.getValue(), shared, false,
+						seen);
 			}
 			// Update denormalised column in messageDependencies if dependency
 			// is in same group as dependent
@@ -1290,12 +1308,18 @@ abstract class JdbcDatabase implements Database<Connection> {
 	public void deleteMessage(Connection txn, MessageId m) throws DbException {
 		PreparedStatement ps = null;
 		try {
-			String sql = "UPDATE messages SET raw = NULL WHERE messageId = ?";
+			String sql = "UPDATE messages SET deleted = TRUE"
+					+ " WHERE messageId = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getBytes());
 			int affected = ps.executeUpdate();
+			if (affected < 0 || affected > 1) throw new DbStateException();
+			ps.close();
+			sql = "UPDATE blocks SET data = NULL WHERE messageId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setBytes(1, m.getBytes());
+			affected = ps.executeUpdate();
 			if (affected < 0) throw new DbStateException();
-			if (affected > 1) throw new DbStateException();
 			ps.close();
 			// Update denormalised column in statuses
 			sql = "UPDATE statuses SET deleted = TRUE WHERE messageId = ?";
@@ -1692,7 +1716,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT groupId, timestamp, raw FROM messages"
+			String sql = "SELECT groupId, timestamp, deleted FROM messages"
 					+ " WHERE messageId = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getBytes());
@@ -1700,15 +1724,23 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (!rs.next()) throw new DbStateException();
 			GroupId g = new GroupId(rs.getBytes(1));
 			long timestamp = rs.getLong(2);
-			byte[] raw = rs.getBytes(3);
+			boolean deleted = rs.getBoolean(3);
 			if (rs.next()) throw new DbStateException();
 			rs.close();
 			ps.close();
-			if (raw == null) throw new MessageDeletedException();
-			if (raw.length <= MESSAGE_HEADER_LENGTH) throw new AssertionError();
-			byte[] body = new byte[raw.length - MESSAGE_HEADER_LENGTH];
-			System.arraycopy(raw, MESSAGE_HEADER_LENGTH, body, 0, body.length);
-			return new Message(m, g, timestamp, body);
+			if (deleted) throw new MessageDeletedException();
+			sql = "SELECT data FROM blocks"
+					+ " WHERE messageId = ? AND blockNumber = 0";
+			ps = txn.prepareStatement(sql);
+			ps.setBytes(1, m.getBytes());
+			rs = ps.executeQuery();
+			if (!rs.next()) throw new DbStateException();
+			byte[] data = rs.getBytes(1);
+			if (data == null) throw new DbStateException();
+			if (rs.next()) throw new DbStateException();
+			rs.close();
+			ps.close();
+			return new Message(m, g, timestamp, data);
 		} catch (SQLException e) {
 			tryToClose(rs, LOG, WARNING);
 			tryToClose(ps, LOG, WARNING);
@@ -2182,7 +2214,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		ResultSet rs = null;
 		try {
 			String sql = "SELECT messageId FROM messages"
-					+ " WHERE state = ? AND raw IS NOT NULL";
+					+ " WHERE state = ? AND deleted = FALSE";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, state.getValue());
 			rs = ps.executeQuery();
diff --git a/bramble-core/src/main/java/org/briarproject/bramble/db/Migration47_48.java b/bramble-core/src/main/java/org/briarproject/bramble/db/Migration47_48.java
new file mode 100644
index 000000000..7ce6e6598
--- /dev/null
+++ b/bramble-core/src/main/java/org/briarproject/bramble/db/Migration47_48.java
@@ -0,0 +1,100 @@
+package org.briarproject.bramble.db;
+
+import org.briarproject.bramble.api.db.DbException;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.logging.Logger;
+
+import static java.lang.System.arraycopy;
+import static java.sql.Types.BINARY;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
+
+class Migration47_48 implements Migration<Connection> {
+
+	private static final Logger LOG = getLogger(Migration47_48.class.getName());
+
+	private final DatabaseTypes dbTypes;
+
+	Migration47_48(DatabaseTypes dbTypes) {
+		this.dbTypes = dbTypes;
+	}
+
+	@Override
+	public int getStartVersion() {
+		return 47;
+	}
+
+	@Override
+	public int getEndVersion() {
+		return 48;
+	}
+
+	@Override
+	public void migrate(Connection txn) throws DbException {
+		Statement s = null;
+		ResultSet rs = null;
+		PreparedStatement ps = null;
+		try {
+			s = txn.createStatement();
+			s.execute("ALTER TABLE messages"
+					+ " ADD COLUMN deleted BOOLEAN DEFAULT FALSE NOT NULL");
+			LOG.info("Created column messages.deleted");
+			s.execute("UPDATE messages SET deleted = TRUE WHERE raw IS NULL");
+			LOG.info("Populated column messages.deleted");
+			s.execute("ALTER TABLE messages"
+					+ " ADD COLUMN blockCount INT DEFAULT 1 NOT NULL");
+			LOG.info("Created column messages.blockCount");
+			s.execute(dbTypes.replaceTypes("CREATE TABLE blocks"
+					+ " (messageId _HASH NOT NULL,"
+					+ " blockNumber INT NOT NULL,"
+					+ " blockLength INT NOT NULL,"
+					+ " data BLOB," // Null if message has been deleted
+					+ " PRIMARY KEY (messageId, blockNumber),"
+					+ " FOREIGN KEY (messageId)"
+					+ " REFERENCES messages (messageId)"
+					+ " ON DELETE CASCADE)"));
+			LOG.info("Created table blocks");
+			rs = s.executeQuery("SELECT messageId, length, raw FROM messages");
+			ps = txn.prepareStatement("INSERT INTO blocks"
+					+ " (messageId, blockNumber, blockLength, data)"
+					+ " VALUES (?, 0, ?, ?)");
+			int migrated = 0;
+			while (rs.next()) {
+				byte[] id = rs.getBytes(1);
+				int length = rs.getInt(2);
+				byte[] raw = rs.getBytes(3);
+				ps.setBytes(1, id);
+				ps.setInt(2, length - MESSAGE_HEADER_LENGTH);
+				if (raw == null) {
+					ps.setNull(3, BINARY);
+				} else {
+					byte[] data = new byte[raw.length - MESSAGE_HEADER_LENGTH];
+					arraycopy(raw, MESSAGE_HEADER_LENGTH, data, 0, data.length);
+					ps.setBytes(3, data);
+				}
+				if (ps.executeUpdate() != 1) throw new DbStateException();
+				migrated++;
+			}
+			ps.close();
+			rs.close();
+			if (LOG.isLoggable(INFO))
+				LOG.info("Migrated " + migrated + " messages");
+			s.execute("ALTER TABLE messages DROP COLUMN raw");
+			LOG.info("Dropped column messages.raw");
+			s.close();
+		} catch (SQLException e) {
+			tryToClose(ps, LOG, WARNING);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+}
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/DatabasePerformanceComparisonTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/DatabasePerformanceComparisonTest.java
index 2da0aae77..aba3fa482 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/DatabasePerformanceComparisonTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/DatabasePerformanceComparisonTest.java
@@ -3,11 +3,9 @@ package org.briarproject.bramble.db;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.system.SystemClock;
 import org.briarproject.bramble.test.TestDatabaseConfig;
-import org.briarproject.bramble.test.TestMessageFactory;
 import org.briarproject.bramble.test.UTest;
 
 import java.io.IOException;
@@ -32,8 +30,7 @@ public abstract class DatabasePerformanceComparisonTest
 	private SecretKey databaseKey = getSecretKey();
 
 	abstract Database<Connection> createDatabase(boolean conditionA,
-			DatabaseConfig databaseConfig, MessageFactory messageFactory,
-			Clock clock);
+			DatabaseConfig databaseConfig, Clock clock);
 
 	@Override
 	protected void benchmark(String name,
@@ -76,8 +73,7 @@ public abstract class DatabasePerformanceComparisonTest
 	private Database<Connection> openDatabase(boolean conditionA)
 			throws DbException {
 		Database<Connection> db = createDatabase(conditionA,
-				new TestDatabaseConfig(testDir), new TestMessageFactory(),
-				new SystemClock());
+				new TestDatabaseConfig(testDir), new SystemClock());
 		db.open(databaseKey, null);
 		return db;
 	}
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseTraceTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseTraceTest.java
index d61983603..e6b49f060 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseTraceTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseTraceTest.java
@@ -3,11 +3,9 @@ package org.briarproject.bramble.db;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.system.SystemClock;
 import org.briarproject.bramble.test.TestDatabaseConfig;
-import org.briarproject.bramble.test.TestMessageFactory;
 import org.briarproject.bramble.util.IoUtils;
 
 import java.io.File;
@@ -26,7 +24,7 @@ public abstract class DatabaseTraceTest extends DatabasePerformanceTest {
 	private SecretKey databaseKey = getSecretKey();
 
 	abstract Database<Connection> createDatabase(DatabaseConfig databaseConfig,
-			MessageFactory messageFactory, Clock clock);
+			Clock clock);
 
 	@Nullable
 	protected abstract File getTraceFile();
@@ -48,8 +46,7 @@ public abstract class DatabaseTraceTest extends DatabasePerformanceTest {
 
 	private Database<Connection> openDatabase() throws DbException {
 		Database<Connection> db = createDatabase(
-				new TestDatabaseConfig(testDir), new TestMessageFactory(),
-				new SystemClock());
+				new TestDatabaseConfig(testDir), new SystemClock());
 		db.open(databaseKey, null);
 		return db;
 	}
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabasePerformanceTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabasePerformanceTest.java
index f682997f7..48446c8e0 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabasePerformanceTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabasePerformanceTest.java
@@ -16,6 +16,6 @@ public class H2DatabasePerformanceTest extends SingleDatabasePerformanceTest {
 	@Override
 	protected JdbcDatabase createDatabase(DatabaseConfig config,
 			MessageFactory messageFactory, Clock clock) {
-		return new H2Database(config, messageFactory, clock);
+		return new H2Database(config, clock);
 	}
 }
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabaseTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabaseTest.java
index 19822113d..0e5ca817d 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabaseTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabaseTest.java
@@ -9,6 +9,6 @@ public class H2DatabaseTest extends JdbcDatabaseTest {
 	@Override
 	protected JdbcDatabase createDatabase(DatabaseConfig config,
 			MessageFactory messageFactory, Clock clock) {
-		return new H2Database(config, messageFactory, clock);
+		return new H2Database(config, clock);
 	}
 }
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabaseTraceTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabaseTraceTest.java
index b87f3992a..2b12f88b0 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabaseTraceTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabaseTraceTest.java
@@ -1,7 +1,6 @@
 package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.db.DatabaseConfig;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 import org.junit.Ignore;
 
@@ -15,8 +14,8 @@ public class H2DatabaseTraceTest extends DatabaseTraceTest {
 
 	@Override
 	Database<Connection> createDatabase(DatabaseConfig databaseConfig,
-			MessageFactory messageFactory, Clock clock) {
-		return new H2Database(databaseConfig, messageFactory, clock) {
+			Clock clock) {
+		return new H2Database(databaseConfig, clock) {
 			@Override
 			@Nonnull
 			String getUrl() {
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/H2HyperSqlDatabasePerformanceComparisonTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/H2HyperSqlDatabasePerformanceComparisonTest.java
index 8fd8d35c8..074ab7b07 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/H2HyperSqlDatabasePerformanceComparisonTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/H2HyperSqlDatabasePerformanceComparisonTest.java
@@ -1,7 +1,6 @@
 package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.db.DatabaseConfig;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 import org.junit.Ignore;
 
@@ -13,11 +12,11 @@ public class H2HyperSqlDatabasePerformanceComparisonTest
 
 	@Override
 	Database<Connection> createDatabase(boolean conditionA,
-			DatabaseConfig databaseConfig, MessageFactory messageFactory,
+			DatabaseConfig databaseConfig,
 			Clock clock) {
 		if (conditionA)
-			return new H2Database(databaseConfig, messageFactory, clock);
-		else return new HyperSqlDatabase(databaseConfig, messageFactory, clock);
+			return new H2Database(databaseConfig, clock);
+		else return new HyperSqlDatabase(databaseConfig, clock);
 	}
 
 	@Override
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/H2MigrationTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/H2MigrationTest.java
index 4646a05b4..29bdbfa5f 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/H2MigrationTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/H2MigrationTest.java
@@ -11,7 +11,7 @@ public class H2MigrationTest extends DatabaseMigrationTest {
 	@Override
 	Database<Connection> createDatabase(
 			List<Migration<Connection>> migrations) {
-		return new H2Database(config, messageFactory, clock) {
+		return new H2Database(config, clock) {
 			@Override
 			List<Migration<Connection>> getMigrations() {
 				return migrations;
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/H2SelfDatabasePerformanceComparisonTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/H2SelfDatabasePerformanceComparisonTest.java
index 5af317910..b3b5bde23 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/H2SelfDatabasePerformanceComparisonTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/H2SelfDatabasePerformanceComparisonTest.java
@@ -1,7 +1,6 @@
 package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.db.DatabaseConfig;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 import org.junit.Ignore;
 
@@ -18,9 +17,9 @@ public class H2SelfDatabasePerformanceComparisonTest
 
 	@Override
 	Database<Connection> createDatabase(boolean conditionA,
-			DatabaseConfig databaseConfig, MessageFactory messageFactory,
+			DatabaseConfig databaseConfig,
 			Clock clock) {
-		return new H2Database(databaseConfig, messageFactory, clock);
+		return new H2Database(databaseConfig, clock);
 	}
 
 	@Override
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/H2SleepDatabasePerformanceComparisonTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/H2SleepDatabasePerformanceComparisonTest.java
index 641f20805..73d382bc5 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/H2SleepDatabasePerformanceComparisonTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/H2SleepDatabasePerformanceComparisonTest.java
@@ -3,7 +3,6 @@ package org.briarproject.bramble.db;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 import org.junit.Ignore;
 
@@ -20,12 +19,11 @@ public class H2SleepDatabasePerformanceComparisonTest
 
 	@Override
 	Database<Connection> createDatabase(boolean conditionA,
-			DatabaseConfig databaseConfig, MessageFactory messageFactory,
-			Clock clock) {
+			DatabaseConfig databaseConfig, Clock clock) {
 		if (conditionA) {
-			return new H2Database(databaseConfig, messageFactory, clock);
+			return new H2Database(databaseConfig, clock);
 		} else {
-			return new H2Database(databaseConfig, messageFactory, clock) {
+			return new H2Database(databaseConfig, clock) {
 				@Override
 				@NotNullByDefault
 				public void commitTransaction(Connection txn)
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlDatabasePerformanceTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlDatabasePerformanceTest.java
index 27b39e924..7e7a67fee 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlDatabasePerformanceTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlDatabasePerformanceTest.java
@@ -17,6 +17,6 @@ public class HyperSqlDatabasePerformanceTest
 	@Override
 	protected JdbcDatabase createDatabase(DatabaseConfig config,
 			MessageFactory messageFactory, Clock clock) {
-		return new HyperSqlDatabase(config, messageFactory, clock);
+		return new HyperSqlDatabase(config, clock);
 	}
 }
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlDatabaseTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlDatabaseTest.java
index bf785e31e..dc1eb86b0 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlDatabaseTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlDatabaseTest.java
@@ -9,6 +9,6 @@ public class HyperSqlDatabaseTest extends JdbcDatabaseTest {
 	@Override
 	protected JdbcDatabase createDatabase(DatabaseConfig config,
 			MessageFactory messageFactory, Clock clock) {
-		return new HyperSqlDatabase(config, messageFactory ,clock);
+		return new HyperSqlDatabase(config, clock);
 	}
 }
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlMigrationTest.java b/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlMigrationTest.java
index f4468728f..7e819905f 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlMigrationTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/db/HyperSqlMigrationTest.java
@@ -11,7 +11,7 @@ public class HyperSqlMigrationTest extends DatabaseMigrationTest {
 	@Override
 	Database<Connection> createDatabase(
 			List<Migration<Connection>> migrations) {
-		return new HyperSqlDatabase(config, messageFactory, clock) {
+		return new HyperSqlDatabase(config, clock) {
 			@Override
 			List<Migration<Connection>> getMigrations() {
 				return migrations;