diff --git a/briar-core/src/main/java/org/briarproject/briar/socialbackup/BackupPayloadDecoderImpl.java b/briar-core/src/main/java/org/briarproject/briar/socialbackup/BackupPayloadDecoderImpl.java
index 145a0ef5a..a2672016b 100644
--- a/briar-core/src/main/java/org/briarproject/briar/socialbackup/BackupPayloadDecoderImpl.java
+++ b/briar-core/src/main/java/org/briarproject/briar/socialbackup/BackupPayloadDecoderImpl.java
@@ -10,6 +10,7 @@ import org.briarproject.bramble.api.crypto.AuthenticatedCipher;
 import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.crypto.SignaturePrivateKey;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.Identity;
@@ -25,18 +26,22 @@ import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.logging.Logger;
 
 import javax.inject.Inject;
 import javax.inject.Provider;
 
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.briar.socialbackup.SocialBackupConstants.AUTH_TAG_BYTES;
 import static org.briarproject.briar.socialbackup.SocialBackupConstants.NONCE_BYTES;
 
-public class BackupPayloadDecoderImpl {
+public class BackupPayloadDecoderImpl implements BackupPayloadDecoder {
 	private final ClientHelper clientHelper;
 	private final Provider<AuthenticatedCipher> cipherProvider;
 	private final SecureRandom secureRandom;
 	private final MessageParser messageParser;
+	private static final Logger LOG =
+			getLogger(BackupPayloadDecoderImpl.class.getName());
 
 	@Inject
 	BackupPayloadDecoderImpl(ClientHelper clientHelper,
@@ -59,7 +64,8 @@ public class BackupPayloadDecoderImpl {
 		System.arraycopy(ciphertextWithNonce, 0, nonce, 0, NONCE_BYTES);
 
 		byte[] ciphertext = new byte[ciphertextWithNonce.length - NONCE_BYTES];
-		System.arraycopy(ciphertextWithNonce, nonce.length, ciphertext, 0, ciphertext.length);
+		System.arraycopy(ciphertextWithNonce, nonce.length, ciphertext, 0,
+				ciphertext.length);
 
 		AuthenticatedCipher cipher = cipherProvider.get();
 		cipher.init(false, secret, nonce);
@@ -68,17 +74,23 @@ public class BackupPayloadDecoderImpl {
 		int decrypted = cipher.process(ciphertext, 0,
 				ciphertext.length, plaintext, 0);
 		if (decrypted != plaintext.length) throw new AssertionError();
+		LOG.info("Backup payload decrypted");
 
 		BdfList backup = clientHelper.toList(plaintext);
 		int version = backup.getLong(0).intValue();
+		LOG.info("Backup payload has version number " + version);
+
 		BdfList bdfIdentity = backup.getList(1);
 		BdfList bdfContactData = backup.getList(2);
 
+		Author a = clientHelper
+				.parseAndValidateAuthor(bdfIdentity.getList(0));
+		PrivateKey signaturePrivateKey =
+				new SignaturePrivateKey(bdfIdentity.getRaw(1));
 		LocalAuthor localAuthor =
-				(LocalAuthor) clientHelper
-						.parseAndValidateAuthor(bdfIdentity.getList(0));
-		//TODO
-		byte[] authorPrivateKeyBytes = bdfIdentity.getRaw(1);
+				new LocalAuthor(a.getId(), a.getFormatVersion(), a.getName(),
+						a.getPublicKey(), signaturePrivateKey);
+		LOG.info("LocalAuthor parsed successfully. Name is " + a.getName());
 
 		PublicKey handshakePublicKey =
 				new AgreementPublicKey(bdfIdentity.getRaw(2));
@@ -89,6 +101,7 @@ public class BackupPayloadDecoderImpl {
 
 		Identity identity = new Identity(localAuthor, handshakePublicKey,
 				handShakePrivateKey, created);
+		LOG.info("New identity created");
 
 		List<ContactData> contactDataList = new ArrayList();
 
@@ -97,26 +110,41 @@ public class BackupPayloadDecoderImpl {
 
 			Author author =
 					clientHelper.parseAndValidateAuthor(bdfData.getList(0));
-			String alias = bdfData.getString(1);
+			LOG.info("Contact author parsed");
+
+			String alias = bdfData.getOptionalString(1);
+			LOG.info("Contact alias is: " + alias);
+
 			// 2 - public key or null
-			byte[] publicKeyBytes = bdfData.getRaw(2);
+			byte[] handshakePublicKeyBytes = bdfData.getOptionalRaw(2);
+			PublicKey contactHandshakePublicKey = (handshakePublicKeyBytes == null)
+					? null
+					: new AgreementPublicKey(handshakePublicKeyBytes);
+			LOG.info("Contact handshake pk parsed");
 
 			// 3 - properties dictionary
 			Map<TransportId, TransportProperties> properties = clientHelper
 					.parseAndValidateTransportPropertiesMap(
 							bdfData.getDictionary(3));
+			LOG.info("Contact transport properties parsed");
+
 			// 4 shard or null
-			BdfList shardList = bdfData.getList(4);
-			Shard shard = shardList == null ? null :
+			BdfList shardList = bdfData.getOptionalList(4);
+			Shard shard = (shardList == null) ? null :
 					messageParser.parseShardMessage(shardList);
+			// TODO validate shard
+		    LOG.info("Contact shard parsed");
+
 			ContactId contactId = new ContactId(i);
 			Contact contact =
 					new Contact(contactId, author, author.getId(), alias,
-							handshakePublicKey, false);
+							contactHandshakePublicKey, false);
 			ContactData contactData =
 					new ContactData(contact, properties, shard);
 			contactDataList.add(contactData);
+			LOG.info("Contact added");
 		}
+		LOG.info("All contacts added");
 		return new SocialBackup(identity, contactDataList, version);
 	}
 }
diff --git a/briar-core/src/main/java/org/briarproject/briar/socialbackup/SocialBackupModule.java b/briar-core/src/main/java/org/briarproject/briar/socialbackup/SocialBackupModule.java
index d66338dbb..0a5530e8f 100644
--- a/briar-core/src/main/java/org/briarproject/briar/socialbackup/SocialBackupModule.java
+++ b/briar-core/src/main/java/org/briarproject/briar/socialbackup/SocialBackupModule.java
@@ -87,17 +87,26 @@ public class SocialBackupModule {
 	}
 
 	@Provides
-	org.briarproject.briar.api.socialbackup.MessageEncoder messageEncoder(MessageEncoderImpl messageEncoder) {
+	BackupPayloadDecoder backupPayloadDecoder(
+			BackupPayloadDecoderImpl backupPayloadDecoder) {
+		return backupPayloadDecoder;
+	}
+
+	@Provides
+	org.briarproject.briar.api.socialbackup.MessageEncoder messageEncoder(
+			MessageEncoderImpl messageEncoder) {
 		return messageEncoder;
 	}
 
 	@Provides
-	org.briarproject.briar.api.socialbackup.MessageParser messageParser(MessageParserImpl messageParser) {
+	org.briarproject.briar.api.socialbackup.MessageParser messageParser(
+			MessageParserImpl messageParser) {
 		return messageParser;
 	}
 
 	@Provides
-	SocialBackupExchangeManager socialBackupExchangeManager(SocialBackupExchangeManagerImpl socialBackupExchangeManager) {
+	SocialBackupExchangeManager socialBackupExchangeManager(
+			SocialBackupExchangeManagerImpl socialBackupExchangeManager) {
 		return socialBackupExchangeManager;
 	}