diff --git a/build.gradle b/build.gradle
index df0b9d4..33583e4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlin_version = '1.1.3'
+    ext.kotlin_version = '1.1.4-2'
     repositories {
         mavenCentral()
     }
@@ -28,6 +28,7 @@ subprojects {
     repositories {
         mavenCentral()
         maven { url 'https://oss.sonatype.org/content/repositories/snapshots/' }
+        jcenter()
     }
     dependencies {
         compile "org.jetbrains.kotlin:kotlin-stdlib-jre7"
@@ -142,6 +143,7 @@ subprojects {
             dependency 'com.madgag.spongycastle:prov:1.56.0.0'
             dependency 'org.apache.commons:commons-lang3:3.6'
             dependency 'org.flywaydb:flyway-core:4.2.0'
+            dependency 'com.beust:klaxon:0.31'
 
             dependency 'args4j:args4j:2.33'
             dependency 'org.ini4j:ini4j:0.5.4'
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/DefaultMessageListener.kt b/core/src/main/kotlin/ch/dissem/bitmessage/DefaultMessageListener.kt
index ac30587..ad32bf9 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/DefaultMessageListener.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/DefaultMessageListener.kt
@@ -23,6 +23,7 @@ import ch.dissem.bitmessage.entity.Plaintext.Status.PUBKEY_REQUESTED
 import ch.dissem.bitmessage.entity.payload.*
 import ch.dissem.bitmessage.entity.valueobject.InventoryVector
 import ch.dissem.bitmessage.exception.DecryptionFailedException
+import ch.dissem.bitmessage.ports.AlreadyStoredException
 import ch.dissem.bitmessage.ports.Labeler
 import ch.dissem.bitmessage.ports.NetworkHandler
 import ch.dissem.bitmessage.utils.Strings.hex
@@ -65,7 +66,7 @@ open class DefaultMessageListener(
 
     protected fun receive(objectMessage: ObjectMessage, getPubkey: GetPubkey) {
         val identity = ctx.addressRepository.findIdentity(getPubkey.ripeTag)
-        if (identity != null && identity.privateKey != null && !identity.isChan) {
+        if (identity?.privateKey != null && !identity.isChan) {
             LOG.info("Got pubkey request for identity " + identity)
             // FIXME: only send pubkey if it wasn't sent in the last TTL.pubkey() days
             ctx.sendPubkey(identity, objectMessage.stream)
@@ -90,7 +91,6 @@ open class DefaultMessageListener(
             }
         } catch (_: DecryptionFailedException) {
         }
-
     }
 
     private fun updatePubkey(address: BitmessageAddress, pubkey: Pubkey) {
@@ -157,14 +157,18 @@ open class DefaultMessageListener(
 
         msg.inventoryVector = iv
         labeler.setLabels(msg)
-        ctx.messageRepository.save(msg)
-        listener.receive(msg)
+        try {
+            ctx.messageRepository.save(msg)
+            listener.receive(msg)
 
-        if (msg.type == Plaintext.Type.MSG && msg.to!!.has(Pubkey.Feature.DOES_ACK)) {
-            msg.ackMessage?.let {
-                ctx.inventory.storeObject(it)
-                ctx.networkHandler.offer(it.inventoryVector)
-            } ?: LOG.debug("ack message expected")
+            if (msg.type == Plaintext.Type.MSG && msg.to!!.has(Pubkey.Feature.DOES_ACK)) {
+                msg.ackMessage?.let {
+                    ctx.inventory.storeObject(it)
+                    ctx.networkHandler.offer(it.inventoryVector)
+                } ?: LOG.debug("ack message expected")
+            }
+        } catch (e: AlreadyStoredException) {
+            LOG.trace("Message was already received before.", e)
         }
     }
 
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/entity/Plaintext.kt b/core/src/main/kotlin/ch/dissem/bitmessage/entity/Plaintext.kt
index 3f0f551..aa28f6e 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/entity/Plaintext.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/entity/Plaintext.kt
@@ -229,7 +229,8 @@ class Plaintext private constructor(
     )
 
     constructor(builder: Builder) : this(
-        type = builder.type,
+        // Calling prepare() here is somewhat ugly, but also a foolproof way to make sure the builder is properly initialized
+        type = builder.prepare().type,
         from = builder.from ?: throw IllegalStateException("sender identity not set"),
         to = builder.to,
         encodingCode = builder.encoding,
@@ -438,7 +439,7 @@ class Plaintext private constructor(
         if (this === other) return true
         if (other !is Plaintext) return false
         return encoding == other.encoding &&
-            from == other.from &&
+            from.address == other.from.address &&
             Arrays.equals(message, other.message) &&
             ackMessage == other.ackMessage &&
             Arrays.equals(to?.ripe, other.to?.ripe) &&
@@ -532,6 +533,7 @@ class Plaintext private constructor(
         private var nonceTrialsPerByte: Long = 0
         private var extraBytes: Long = 0
         private var destinationRipe: ByteArray? = null
+        private var preventAck: Boolean = false
         internal var encoding: Long = 0
         internal var message = ByteArray(0)
         internal var ackData: ByteArray? = null
@@ -611,6 +613,12 @@ class Plaintext private constructor(
             return this
         }
 
+        @JvmOverloads
+        fun preventAck(preventAck: Boolean = true): Builder {
+            this.preventAck = preventAck
+            return this
+        }
+
         fun encoding(encoding: Encoding): Builder {
             this.encoding = encoding.code
             return this
@@ -655,7 +663,7 @@ class Plaintext private constructor(
             return this
         }
 
-        fun signature(signature: ByteArray): Builder {
+        fun signature(signature: ByteArray?): Builder {
             this.signature = signature
             return this
         }
@@ -700,7 +708,7 @@ class Plaintext private constructor(
             return this
         }
 
-        fun build(): Plaintext {
+        internal fun prepare(): Builder {
             if (from == null) {
                 from = BitmessageAddress(Factory.createPubkey(
                     addressVersion,
@@ -715,12 +723,19 @@ class Plaintext private constructor(
             if (to == null && type != Type.BROADCAST && destinationRipe != null) {
                 to = BitmessageAddress(0, 0, destinationRipe!!)
             }
-            if (type == MSG && ackMessage == null && ackData == null) {
+            if (preventAck) {
+                ackData = null
+                ackMessage = null
+            } else if (type == MSG && ackMessage == null && ackData == null) {
                 ackData = cryptography().randomBytes(Msg.ACK_LENGTH)
             }
             if (ttl <= 0) {
                 ttl = TTL.msg
             }
+            return this
+        }
+
+        fun build(): Plaintext {
             return Plaintext(this)
         }
     }
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/Label.kt b/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/Label.kt
index 6fd4fd6..3bba8d6 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/Label.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/Label.kt
@@ -25,7 +25,8 @@ data class Label(
     /**
      * RGBA representation for the color.
      */
-    var color: Int = 0
+    var color: Int = 0,
+    var ord: Int = 1000
 ) : Serializable {
 
     var id: Any? = null
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/PrivateKey.kt b/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/PrivateKey.kt
index cfc618a..c7f0b54 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/PrivateKey.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/entity/valueobject/PrivateKey.kt
@@ -34,48 +34,37 @@ import java.util.*
  * Represents a private key. Additional information (stream, version, features, ...) is stored in the accompanying
  * [Pubkey] object.
  */
-class PrivateKey : Streamable {
-
-    val privateSigningKey: ByteArray
-    val privateEncryptionKey: ByteArray
+data class PrivateKey(
+    val privateSigningKey: ByteArray,
+    val privateEncryptionKey: ByteArray,
 
     val pubkey: Pubkey
+) : Streamable {
 
-    constructor(shorter: Boolean, stream: Long, nonceTrialsPerByte: Long, extraBytes: Long, vararg features: Pubkey.Feature) {
-        var privSK: ByteArray
-        var pubSK: ByteArray
-        var privEK: ByteArray
-        var pubEK: ByteArray
-        var ripe: ByteArray
-        do {
-            privSK = cryptography().randomBytes(PRIVATE_KEY_SIZE)
-            privEK = cryptography().randomBytes(PRIVATE_KEY_SIZE)
-            pubSK = cryptography().createPublicKey(privSK)
-            pubEK = cryptography().createPublicKey(privEK)
-            ripe = Pubkey.getRipe(pubSK, pubEK)
-        } while (ripe[0].toInt() != 0 || shorter && ripe[1].toInt() != 0)
-        this.privateSigningKey = privSK
-        this.privateEncryptionKey = privEK
-        this.pubkey = cryptography().createPubkey(Pubkey.LATEST_VERSION, stream, privateSigningKey, privateEncryptionKey,
-            nonceTrialsPerByte, extraBytes, *features)
-    }
-
-    constructor(privateSigningKey: ByteArray, privateEncryptionKey: ByteArray, pubkey: Pubkey) {
-        this.privateSigningKey = privateSigningKey
-        this.privateEncryptionKey = privateEncryptionKey
-        this.pubkey = pubkey
-    }
+    constructor(
+        shorter: Boolean,
+        stream: Long,
+        nonceTrialsPerByte: Long, extraBytes: Long,
+        vararg features: Pubkey.Feature
+    ) : this(
+        Builder(version = Pubkey.LATEST_VERSION, stream = stream, shorter = shorter)
+            .random()
+            .nonceTrialsPerByte(nonceTrialsPerByte)
+            .extraBytes(extraBytes)
+            .features(features)
+            .generate())
 
     constructor(address: BitmessageAddress, passphrase: String) : this(address.version, address.stream, passphrase)
 
-    constructor(version: Long, stream: Long, passphrase: String) : this(Builder(version, stream, false).seed(passphrase).generate())
+    constructor(version: Long, stream: Long, passphrase: String) : this(
+        Builder(version, stream, false).seed(passphrase).generate()
+    )
 
-    private constructor(builder: Builder) {
-        this.privateSigningKey = builder.privSK!!
-        this.privateEncryptionKey = builder.privEK!!
-        this.pubkey = Factory.createPubkey(builder.version, builder.stream, builder.pubSK!!, builder.pubEK!!,
-            InternalContext.NETWORK_NONCE_TRIALS_PER_BYTE, InternalContext.NETWORK_EXTRA_BYTES)
-    }
+    private constructor(builder: Builder) : this(
+        builder.privSK!!, builder.privEK!!,
+        Factory.createPubkey(builder.version, builder.stream, builder.pubSK!!, builder.pubEK!!,
+            builder.nonceTrialsPerByte, builder.extraBytes, *builder.features)
+    )
 
     private class Builder internal constructor(internal val version: Long, internal val stream: Long, internal val shorter: Boolean) {
 
@@ -87,6 +76,30 @@ class PrivateKey : Streamable {
         internal var pubSK: ByteArray? = null
         internal var pubEK: ByteArray? = null
 
+        internal var nonceTrialsPerByte = InternalContext.NETWORK_NONCE_TRIALS_PER_BYTE
+        internal var extraBytes = InternalContext.NETWORK_EXTRA_BYTES
+        internal var features: Array<out Pubkey.Feature> = emptyArray()
+
+        internal fun random(): Builder {
+            seed = cryptography().randomBytes(1024)
+            return this
+        }
+
+        fun nonceTrialsPerByte(nonceTrialsPerByte: Long): Builder {
+            this.nonceTrialsPerByte = nonceTrialsPerByte
+            return this
+        }
+
+        fun extraBytes(extraBytes: Long): Builder {
+            this.extraBytes = extraBytes
+            return this
+        }
+
+        fun features(features: Array<out Pubkey.Feature>): Builder {
+            this.features = features
+            return this
+        }
+
         internal fun seed(passphrase: String): Builder {
             try {
                 seed = passphrase.toByteArray(charset("UTF-8"))
@@ -143,6 +156,13 @@ class PrivateKey : Streamable {
         Encode.varBytes(privateEncryptionKey, buffer)
     }
 
+    override fun equals(other: Any?) = other is PrivateKey
+        && Arrays.equals(privateEncryptionKey, other.privateEncryptionKey)
+        && Arrays.equals(privateSigningKey, other.privateSigningKey)
+        && pubkey == other.pubkey
+
+    override fun hashCode() = pubkey.hashCode()
+
     companion object {
         @JvmField val PRIVATE_KEY_SIZE = 32
 
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractCryptography.kt b/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractCryptography.kt
index f6b779b..5792f0f 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractCryptography.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractCryptography.kt
@@ -198,10 +198,10 @@ abstract class AbstractCryptography protected constructor(@JvmField protected va
     }
 
     companion object {
-        protected val LOG = LoggerFactory.getLogger(Cryptography::class.java)
+        protected val LOG = LoggerFactory.getLogger(Cryptography::class.java)!!
         private val RANDOM = SecureRandom()
         private val TWO = BigInteger.valueOf(2)
-        private val TWO_POW_64 = TWO.pow(64)
-        private val TWO_POW_16 = TWO.pow(16)
+        private val TWO_POW_64 = TWO.pow(64)!!
+        private val TWO_POW_16 = TWO.pow(16)!!
     }
 }
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractMessageRepository.kt b/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractMessageRepository.kt
index b6d2108..d426dac 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractMessageRepository.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/ports/AbstractMessageRepository.kt
@@ -49,6 +49,8 @@ abstract class AbstractMessageRepository : MessageRepository, InternalContext.Co
         }
     }
 
+    override fun getAllMessages() = find("1=1")
+
     override fun getMessage(id: Any): Plaintext {
         if (id is Long) {
             return single(find("id=" + id)) ?: throw IllegalArgumentException("There  is no message with id $id")
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/ports/AlreadyStoredException.kt b/core/src/main/kotlin/ch/dissem/bitmessage/ports/AlreadyStoredException.kt
new file mode 100644
index 0000000..619f546
--- /dev/null
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/ports/AlreadyStoredException.kt
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2017 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.ports
+
+/**
+ * Should be thrown if a received and decrypted message can't be stored because it has already been received and stored.
+ * (So it's not announced again to the client.)
+ */
+class AlreadyStoredException(message: String? = null, cause: Throwable? = null) : Exception(message, cause)
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/ports/MessageRepository.kt b/core/src/main/kotlin/ch/dissem/bitmessage/ports/MessageRepository.kt
index 51e0d02..68fac7a 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/ports/MessageRepository.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/ports/MessageRepository.kt
@@ -28,8 +28,12 @@ interface MessageRepository {
 
     fun getLabels(vararg types: Label.Type): List<Label>
 
+    fun save(label: Label)
+
     fun countUnread(label: Label?): Int
 
+    fun getAllMessages(): List<Plaintext>
+
     fun getMessage(id: Any): Plaintext
 
     fun getMessage(iv: InventoryVector): Plaintext?
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/utils/Base58.kt b/core/src/main/kotlin/ch/dissem/bitmessage/utils/Base58.kt
index 7f98f93..216e07d 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/utils/Base58.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/utils/Base58.kt
@@ -88,21 +88,22 @@ object Base58 {
         val input58 = ByteArray(input.length)
         // Transform the String to a base58 byte sequence
         for (i in 0..input.length - 1) {
-            val c = input[i]
+            val c = input[i].toInt()
 
-            var digit58 = -1
-            if (c.toInt() < 128) {
-                digit58 = INDEXES[c.toInt()]
+            val digit58 = if (c < 128) {
+                INDEXES[c]
+            } else {
+                -1
             }
             if (digit58 < 0) {
-                throw AddressFormatException("Illegal character $c at $i")
+                throw AddressFormatException("Illegal character ${input[i]} at $i")
             }
 
             input58[i] = digit58.toByte()
         }
         // Count leading zeroes
         var zeroCount = 0
-        while (zeroCount < input58.size && input58[zeroCount].toInt() == 0) {
+        while (zeroCount < input58.size && input58[zeroCount] == 0.toByte()) {
             ++zeroCount
         }
         // The encoding
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/utils/Base64.kt b/core/src/main/kotlin/ch/dissem/bitmessage/utils/Base64.kt
new file mode 100644
index 0000000..f37415e
--- /dev/null
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/utils/Base64.kt
@@ -0,0 +1,664 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils
+
+
+/**
+ * Utilities for encoding and decoding the Base64 representation of
+ * binary data.  See RFCs <a
+ * href="http://www.ietf.org/rfc/rfc2045.txt">2045</a> and <a
+ * href="http://www.ietf.org/rfc/rfc3548.txt">3548</a>.
+ */
+object Base64 {
+    /**
+     * Encoder flag bit to omit the padding '=' characters at the end
+     * of the output (if any).
+     */
+    const val NO_PADDING = 1
+
+    /**
+     * Encoder flag bit to omit all line terminators (i.e., the output
+     * will be on one long line).
+     */
+    const val NO_WRAP = 2
+
+    /**
+     * Encoder flag bit to indicate lines should be terminated with a
+     * CRLF pair instead of just an LF.  Has no effect if `NO_WRAP` is specified as well.
+     */
+    const val CRLF = 4
+
+    /**
+     * Encoder/decoder flag bit to indicate using the "URL and
+     * filename safe" variant of Base64 (see RFC 3548 section 4) where
+     * `-` and `_` are used in place of `+` and
+     * `/`.
+     */
+    const val URL_SAFE = 8
+
+    /**
+     * Default values for encoder/decoder flags.
+     */
+    const val DEFAULT = NO_WRAP
+
+
+    //  --------------------------------------------------------
+    //  decoding
+    //  --------------------------------------------------------
+
+    /**
+     * Decode the Base64-encoded data in input and return the data in
+     * a new byte array.
+
+     *
+     * The padding '=' characters at the end are considered optional, but
+     * if any are present, there must be the correct number of them.
+
+     * @param str    the input String to decode, which is converted to
+     * *               bytes using the default charset
+     * *
+     * @param flags  controls certain features of the decoded output.
+     * *               Pass `DEFAULT` to decode standard Base64.
+     * *
+     * *
+     * @throws IllegalArgumentException if the input contains
+     * * incorrect padding
+     */
+    @JvmStatic
+    fun decode(str: String, flags: Int = DEFAULT): ByteArray {
+        val input = str.toByteArray(Charsets.US_ASCII)
+        return decode(input, 0, input.size, flags)
+    }
+
+    /**
+     * Decode the Base64-encoded data in input and return the data in
+     * a new byte array.
+
+     *
+     * The padding '=' characters at the end are considered optional, but
+     * if any are present, there must be the correct number of them.
+
+     * @param input  the data to decode
+     * *
+     * @param offset the position within the input array at which to start
+     * *
+     * @param len    the number of bytes of input to decode
+     * *
+     * @param flags  controls certain features of the decoded output.
+     * *               Pass `DEFAULT` to decode standard Base64.
+     * *
+     * *
+     * @throws IllegalArgumentException if the input contains
+     * * incorrect padding
+     */
+    @JvmStatic
+    fun decode(input: ByteArray, offset: Int, len: Int, flags: Int = DEFAULT): ByteArray {
+        // Allocate space for the most data the input could represent.
+        // (It could contain less if it contains whitespace, etc.)
+        val decoder = Decoder(Options(flags), ByteArray(len * 3 / 4))
+
+        if (!decoder.process(input, offset, len, true)) {
+            throw IllegalArgumentException("bad base-64")
+        }
+
+        // Maybe we got lucky and allocated exactly enough output space.
+        if (decoder.op == decoder.output.size) {
+            return decoder.output
+        }
+
+        // Need to shorten the array, so allocate a new one of the
+        // right size and copy.
+        val temp = ByteArray(decoder.op)
+        System.arraycopy(decoder.output, 0, temp, 0, decoder.op)
+        return temp
+    }
+
+    //  --------------------------------------------------------
+    //  encoding
+    //  --------------------------------------------------------
+
+    /**
+     * Base64-encode the given data and return a newly allocated
+     * String with the result.
+
+     * @param input  the data to encode
+     * *
+     * @param flags  controls certain features of the encoded output.
+     * *               Passing `DEFAULT` results in output that
+     * *               adheres to RFC 2045.
+     */
+    fun encodeToString(input: ByteArray, flags: Int = DEFAULT): String {
+        return String(encode(input, 0, input.size, flags), Charsets.US_ASCII)
+    }
+
+    /**
+     * Base64-encode the given data and return a newly allocated
+     * byte[] with the result.
+
+     * @param input  the data to encode
+     * *
+     * @param offset the position within the input array at which to
+     * *               start
+     * *
+     * @param len    the number of bytes of input to encode
+     * *
+     * @param flags  controls certain features of the encoded output.
+     * *               Passing `DEFAULT` results in output that
+     * *               adheres to RFC 2045.
+     */
+    fun encode(input: ByteArray, offset: Int, len: Int, flags: Int): ByteArray {
+        // Compute the exact length of the array we will produce.
+        var output_len = len / 3 * 4
+
+        val options = Options(flags)
+
+        // Account for the tail of the data and the padding bytes, if any.
+        if (options.do_padding) {
+            if (len % 3 > 0) {
+                output_len += 4
+            }
+        } else {
+            when (len % 3) {
+                0 -> {
+                }
+                1 -> output_len += 2
+                2 -> output_len += 3
+            }
+        }
+
+        // Account for the newlines, if any.
+        if (options.do_newline && len > 0) {
+            output_len += ((len - 1) / (3 * Encoder.LINE_GROUPS) + 1) * if (options.do_cr) 2 else 1
+        }
+
+        val encoder = Encoder(options, ByteArray(output_len))
+        encoder.process(input, offset, len, true)
+
+        assert(encoder.op == output_len)
+
+        return encoder.output
+    }
+}
+
+class Options(flags: Int) {
+    val do_padding = flags and Base64.NO_PADDING == 0
+    val do_newline = flags and Base64.NO_WRAP == 0
+    val do_cr = flags and Base64.CRLF != 0
+    val url_safe = flags and Base64.URL_SAFE == 0
+}
+
+private abstract class Coder(val output: ByteArray) {
+    var op = 0
+
+    /**
+     * Encode/decode another block of input data.  this.output is
+     * provided by the caller, and must be big enough to hold all
+     * the coded data.  On exit, this.opwill be set to the length
+     * of the coded data.
+     *
+     * @param finish true if this is the final call to process for
+     *        this object.  Will finalize the coder state and
+     *        include any final bytes in the output.
+     *
+     * @return true if the input so far is good; false if some
+     *         error has been detected in the input stream..
+     */
+    abstract fun process(input: ByteArray, offset: Int, len: Int, finish: Boolean): Boolean
+
+    /**
+     * @return the maximum number of bytes a call to process()
+     *         could produce for the given number of input bytes.  This may
+     *         be an overestimate.
+     */
+    abstract fun maxOutputSize(len: Int): Int
+}
+
+private class Decoder(options: Options, output: ByteArray) : Coder(output) {
+
+    /**
+     * States 0-3 are reading through the next input tuple.
+     * State 4 is having read one '=' and expecting exactly
+     * one more.
+     * State 5 is expecting no more data or padding characters
+     * in the input.
+     * State 6 is the error state; an error has been detected
+     * in the input and no future input can "fix" it.
+     */
+    private var state: Int = 0   // state number (0 to 6)
+    private var value: Int = 0
+
+    private val alphabet = if (options.url_safe) DECODE else DECODE_WEBSAFE
+
+    /**
+     * @return an overestimate for the number of bytes `len` bytes could decode to.
+     */
+    override fun maxOutputSize(len: Int): Int {
+        return len * 3 / 4 + 10
+    }
+
+    /**
+     * Decode another block of input data.
+
+     * @return true if the state machine is still healthy.  false if
+     * *         bad base-64 data has been detected in the input stream.
+     */
+    override fun process(input: ByteArray, offset: Int, len: Int, finish: Boolean): Boolean {
+        var end = len
+        if (this.state == 6) return false
+
+        var p = offset
+        end += offset
+
+        // Using local variables makes the decoder about 12%
+        // faster than if we manipulate the member variables in
+        // the loop.  (Even alphabet makes a measurable
+        // difference, which is somewhat surprising to me since
+        // the member variable is final.)
+        var state = this.state
+        var value = this.value
+        var op = 0
+        val output = this.output
+        val alphabet = this.alphabet
+
+        while (p < end) {
+            // Try the fast path:  we're starting a new tuple and the
+            // next four bytes of the input stream are all data
+            // bytes.  This corresponds to going through states
+            // 0-1-2-3-0.  We expect to use this method for most of
+            // the data.
+            //
+            // If any of the next four bytes of input are non-data
+            // (whitespace, etc.), value will end up negative.  (All
+            // the non-data values in decode are small negative
+            // numbers, so shifting any of them up and or'ing them
+            // together will result in a value with its top bit set.)
+            //
+            // You can remove this whole block and the output should
+            // be the same, just slower.
+            if (state == 0) {
+                fun nextVal(): Int {
+                    value = alphabet[input[p].toInt() and 0xff] shl 18 or
+                        (alphabet[input[p + 1].toInt() and 0xff] shl 12) or
+                        (alphabet[input[p + 2].toInt() and 0xff] shl 6) or
+                        alphabet[input[p + 3].toInt() and 0xff]
+                    return value
+                }
+                while (p + 4 <= end && nextVal() >= 0) {
+                    output[op + 2] = value.toByte()
+                    output[op + 1] = (value shr 8).toByte()
+                    output[op] = (value shr 16).toByte()
+                    op += 3
+                    p += 4
+                }
+                if (p >= end) break
+            }
+
+            // The fast path isn't available -- either we've read a
+            // partial tuple, or the next four input bytes aren't all
+            // data, or whatever.  Fall back to the slower state
+            // machine implementation.
+
+            val d = alphabet[input[p++].toInt() and 0xff]
+
+            when (state) {
+                0 -> if (d >= 0) {
+                    value = d
+                    ++state
+                } else if (d != SKIP) {
+                    this.state = 6
+                    return false
+                }
+
+                1 -> if (d >= 0) {
+                    value = value shl 6 or d
+                    ++state
+                } else if (d != SKIP) {
+                    this.state = 6
+                    return false
+                }
+
+                2 -> if (d >= 0) {
+                    value = value shl 6 or d
+                    ++state
+                } else if (d == EQUALS) {
+                    // Emit the last (partial) output tuple;
+                    // expect exactly one more padding character.
+                    output[op++] = (value shr 4).toByte()
+                    state = 4
+                } else if (d != SKIP) {
+                    this.state = 6
+                    return false
+                }
+
+                3 -> if (d >= 0) {
+                    // Emit the output triple and return to state 0.
+                    value = value shl 6 or d
+                    output[op + 2] = value.toByte()
+                    output[op + 1] = (value shr 8).toByte()
+                    output[op] = (value shr 16).toByte()
+                    op += 3
+                    state = 0
+                } else if (d == EQUALS) {
+                    // Emit the last (partial) output tuple;
+                    // expect no further data or padding characters.
+                    output[op + 1] = (value shr 2).toByte()
+                    output[op] = (value shr 10).toByte()
+                    op += 2
+                    state = 5
+                } else if (d != SKIP) {
+                    this.state = 6
+                    return false
+                }
+
+                4 -> if (d == EQUALS) {
+                    ++state
+                } else if (d != SKIP) {
+                    this.state = 6
+                    return false
+                }
+
+                5 -> if (d != SKIP) {
+                    this.state = 6
+                    return false
+                }
+            }
+        }
+
+        if (!finish) {
+            // We're out of input, but a future call could provide
+            // more.
+            this.state = state
+            this.value = value
+            this.op = op
+            return true
+        }
+
+        // Done reading input.  Now figure out where we are left in
+        // the state machine and finish up.
+
+        when (state) {
+            0 -> {
+            }
+            1 -> {
+                // Read one extra input byte, which isn't enough to
+                // make another output byte.  Illegal.
+                this.state = 6
+                return false
+            }
+            2 ->
+                // Read two extra input bytes, enough to emit 1 more
+                // output byte.  Fine.
+                output[op++] = (value shr 4).toByte()
+            3 -> {
+                // Read three extra input bytes, enough to emit 2 more
+                // output bytes.  Fine.
+                output[op++] = (value shr 10).toByte()
+                output[op++] = (value shr 2).toByte()
+            }
+            4 -> {
+                // Read one padding '=' when we expected 2.  Illegal.
+                this.state = 6
+                return false
+            }
+            5 -> {
+            }
+        }// Output length is a multiple of three.  Fine.
+        // Read all the padding '='s we expected and no more.
+        // Fine.
+
+        this.state = state
+        this.op = op
+        return true
+    }
+
+    companion object {
+        /**
+         * Lookup table for turning bytes into their position in the
+         * Base64 alphabet.
+         */
+        private val DECODE = intArrayOf(
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
+            52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1,
+            -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
+            15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
+            -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+            41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
+        )
+
+        /**
+         * Decode lookup table for the "web safe" variant (RFC 3548
+         * sec. 4) where - and _ replace + and /.
+         */
+        private val DECODE_WEBSAFE = intArrayOf(
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1,
+            52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1,
+            -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
+            15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63,
+            -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+            41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
+        )
+
+        /** Non-data values in the DECODE arrays.  */
+        private val SKIP = -1
+        private val EQUALS = -2
+    }
+}
+
+private class Encoder(val options: Options, output: ByteArray) : Coder(output) {
+
+    private val alphabet: ByteArray = if (options.url_safe) ENCODE else ENCODE_WEBSAFE
+
+    private val tail = ByteArray(2)
+    private var tailLen = 0
+    private var count = if (options.do_newline) LINE_GROUPS else -1
+
+    /**
+     * @return an overestimate for the number of bytes `len` bytes could encode to.
+     */
+    override fun maxOutputSize(len: Int): Int {
+        return len * 8 / 5 + 10
+    }
+
+    override fun process(input: ByteArray, offset: Int, len: Int, finish: Boolean): Boolean {
+        var end = len
+        // Using local variables makes the encoder about 9% faster.
+        val alphabet = this.alphabet
+        val output = this.output
+        var op = 0
+        var count = this.count
+
+        var p = offset
+        end += offset
+        var v = -1
+
+        // First we need to concatenate the tail of the previous call
+        // with any input bytes available now and see if we can empty
+        // the tail.
+
+        when (tailLen) {
+            0 -> {
+            }
+
+            1 -> {
+                if (p + 2 <= end) {
+                    // A 1-byte tail with at least 2 bytes of
+                    // input available now.
+                    v = tail[0].toInt() and 0xff shl 16 or
+                        (input[p++].toInt() and 0xff shl 8) or
+                        (input[p++].toInt() and 0xff)
+                    tailLen = 0
+                }
+            }
+
+            2 -> if (p + 1 <= end) {
+                // A 2-byte tail with at least 1 byte of input.
+                v = tail[0].toInt() and 0xff shl 16 or
+                    (tail[1].toInt() and 0xff shl 8) or
+                    (input[p++].toInt() and 0xff)
+                tailLen = 0
+            }
+        }// There was no tail.
+
+        if (v != -1) {
+            output[op++] = alphabet[v shr 18 and 0x3f]
+            output[op++] = alphabet[v shr 12 and 0x3f]
+            output[op++] = alphabet[v shr 6 and 0x3f]
+            output[op++] = alphabet[v and 0x3f]
+            if (--count == 0) {
+                if (options.do_cr) output[op++] = CR
+                output[op++] = NL
+                count = LINE_GROUPS
+            }
+        }
+
+        // At this point either there is no tail, or there are fewer
+        // than 3 bytes of input available.
+
+        // The main loop, turning 3 input bytes into 4 output bytes on
+        // each iteration.
+        while (p + 3 <= end) {
+            v = input[p].toInt() and 0xff shl 16 or
+                (input[p + 1].toInt() and 0xff shl 8) or
+                (input[p + 2].toInt() and 0xff)
+            output[op] = alphabet[v shr 18 and 0x3f]
+            output[op + 1] = alphabet[v shr 12 and 0x3f]
+            output[op + 2] = alphabet[v shr 6 and 0x3f]
+            output[op + 3] = alphabet[v and 0x3f]
+            p += 3
+            op += 4
+            if (--count == 0) {
+                if (options.do_cr) output[op++] = CR
+                output[op++] = NL
+                count = LINE_GROUPS
+            }
+        }
+
+        if (finish) {
+            // Finish up the tail of the input.  Note that we need to
+            // consume any bytes in tail before any bytes
+            // remaining in input; there should be at most two bytes
+            // total.
+
+            if (p - tailLen == end - 1) {
+                var t = 0
+                v = (if (tailLen > 0) tail[t++] else input[p++]).toInt() and 0xff shl 4
+                tailLen -= t
+                output[op++] = alphabet[v shr 6 and 0x3f]
+                output[op++] = alphabet[v and 0x3f]
+                if (options.do_padding) {
+                    output[op++] = PAD
+                    output[op++] = PAD
+                }
+                if (options.do_newline) {
+                    if (options.do_cr) output[op++] = CR
+                    output[op++] = NL
+                }
+            } else if (p - tailLen == end - 2) {
+                var t = 0
+                v = (if (tailLen > 1) tail[t++] else input[p++]).toInt() and 0xff shl 10 or ((if (tailLen > 0) tail[t++] else input[p++]).toInt() and 0xff shl 2)
+                tailLen -= t
+                output[op++] = alphabet[v shr 12 and 0x3f]
+                output[op++] = alphabet[v shr 6 and 0x3f]
+                output[op++] = alphabet[v and 0x3f]
+                if (options.do_padding) {
+                    output[op++] = PAD
+                }
+                if (options.do_newline) {
+                    if (options.do_cr) output[op++] = CR
+                    output[op++] = NL
+                }
+            } else if (options.do_newline && op > 0 && count != LINE_GROUPS) {
+                if (options.do_cr) output[op++] = CR
+                output[op++] = NL
+            }
+
+            assert(tailLen == 0)
+            assert(p == end)
+        } else {
+            // Save the leftovers in tail to be consumed on the next
+            // call to encodeInternal.
+
+            if (p == end - 1) {
+                tail[tailLen++] = input[p]
+            } else if (p == end - 2) {
+                tail[tailLen++] = input[p]
+                tail[tailLen++] = input[p + 1]
+            }
+        }
+
+        this.op = op
+        this.count = count
+
+        return true
+    }
+
+    companion object {
+        private const val PAD = '='.toByte()
+        private const val CR = '\r'.toByte()
+        private const val NL = '\n'.toByte()
+        /**
+         * Emit a new line every this many output tuples.  Corresponds to
+         * a 76-character line length (the maximum allowable according to
+         * [RFC 2045](http://www.ietf.org/rfc/rfc2045.txt)).
+         */
+        val LINE_GROUPS = 19
+
+        /**
+         * Lookup table for turning Base64 alphabet positions (6 bits)
+         * into output bytes.
+         */
+        private val ENCODE = charArrayOf(
+            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
+            'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
+            'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
+            'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
+            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
+        ).map { it.toByte() }.toByteArray()
+
+        /**
+         * Lookup table for turning Base64 alphabet positions (6 bits)
+         * into output bytes.
+         */
+        private val ENCODE_WEBSAFE = charArrayOf(
+            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
+            'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
+            'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
+            'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
+            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_'
+        ).map { it.toByte() }.toByteArray()
+    }
+}
diff --git a/core/src/main/kotlin/ch/dissem/bitmessage/utils/UnixTime.kt b/core/src/main/kotlin/ch/dissem/bitmessage/utils/UnixTime.kt
index d21bc2e..b542bd9 100644
--- a/core/src/main/kotlin/ch/dissem/bitmessage/utils/UnixTime.kt
+++ b/core/src/main/kotlin/ch/dissem/bitmessage/utils/UnixTime.kt
@@ -23,15 +23,15 @@ object UnixTime {
     /**
      * Length of a minute in seconds, intended for use with [.now].
      */
-    @JvmField val MINUTE = 60L
+    const val MINUTE = 60L
     /**
      * Length of an hour in seconds, intended for use with [.now].
      */
-    @JvmField val HOUR = 60L * MINUTE
+    const val HOUR = 60L * MINUTE
     /**
      * Length of a day in seconds, intended for use with [.now].
      */
-    @JvmField val DAY = 24L * HOUR
+    const val DAY = 24L * HOUR
 
     /**
      * @return the time in second based Unix time ([System.currentTimeMillis]/1000)
diff --git a/core/src/main/resources/nodes.txt b/core/src/main/resources/nodes.txt
index bce982e..23e85d2 100644
--- a/core/src/main/resources/nodes.txt
+++ b/core/src/main/resources/nodes.txt
@@ -1,6 +1,6 @@
 [stream 1]
 
-dissem.ch:8444
+bitmessage.dissem.ch:8444
 bootstrap8080.bitmessage.org:8080
 bootstrap8444.bitmessage.org:8444
 
diff --git a/core/src/test/kotlin/ch/dissem/bitmessage/BitmessageContextTest.kt b/core/src/test/kotlin/ch/dissem/bitmessage/BitmessageContextTest.kt
index 24e8ae3..d767789 100644
--- a/core/src/test/kotlin/ch/dissem/bitmessage/BitmessageContextTest.kt
+++ b/core/src/test/kotlin/ch/dissem/bitmessage/BitmessageContextTest.kt
@@ -218,7 +218,7 @@ class BitmessageContextTest {
         verify(ctx.internals.proofOfWorkRepository, timeout(10000)).putObject(
             argThat { payload.type == ObjectType.MSG }, eq(1000L), eq(1000L))
         assertEquals(2, testPowRepo.added)
-        verify(ctx.messages, timeout(10000).atLeastOnce()).save(argThat { type == Type.MSG })
+        verify(ctx.messages, timeout(10000).atLeastOnce()).save(argThat<Plaintext> { type == Type.MSG })
     }
 
     @Test
@@ -228,7 +228,7 @@ class BitmessageContextTest {
             "Subject", "Message")
         verify(testPowRepo, timeout(10000).atLeastOnce())
             .putObject(argThat { payload.type == ObjectType.GET_PUBKEY }, eq(1000L), eq(1000L))
-        verify(ctx.messages, timeout(10000).atLeastOnce()).save(argThat { type == Type.MSG })
+        verify(ctx.messages, timeout(10000).atLeastOnce()).save(argThat<Plaintext> { type == Type.MSG })
     }
 
     @Test(expected = IllegalArgumentException::class)
@@ -245,7 +245,7 @@ class BitmessageContextTest {
         verify(ctx.internals.proofOfWorkRepository, timeout(1000).atLeastOnce())
             .putObject(argThat { payload.type == ObjectType.BROADCAST }, eq(1000L), eq(1000L))
         verify(testPowEngine).calculateNonce(any(), any(), any())
-        verify(ctx.messages, timeout(10000).atLeastOnce()).save(argThat { type == Type.BROADCAST })
+        verify(ctx.messages, timeout(10000).atLeastOnce()).save(argThat<Plaintext> { type == Type.BROADCAST })
     }
 
     @Test(expected = IllegalArgumentException::class)
diff --git a/core/src/test/kotlin/ch/dissem/bitmessage/DefaultMessageListenerTest.kt b/core/src/test/kotlin/ch/dissem/bitmessage/DefaultMessageListenerTest.kt
index a96430f..57db6fe 100644
--- a/core/src/test/kotlin/ch/dissem/bitmessage/DefaultMessageListenerTest.kt
+++ b/core/src/test/kotlin/ch/dissem/bitmessage/DefaultMessageListenerTest.kt
@@ -108,7 +108,7 @@ class DefaultMessageListenerTest : TestBase() {
 
         listener.receive(objectMessage)
 
-        verify(ctx.messageRepository, atLeastOnce()).save(argThat { type == MSG })
+        verify(ctx.messageRepository, atLeastOnce()).save(argThat<Plaintext> { type == MSG })
     }
 
     @Test
@@ -131,6 +131,6 @@ class DefaultMessageListenerTest : TestBase() {
 
         listener.receive(objectMessage)
 
-        verify(ctx.messageRepository, atLeastOnce()).save(argThat { type == BROADCAST })
+        verify(ctx.messageRepository, atLeastOnce()).save(argThat<Plaintext> { type == BROADCAST })
     }
 }
diff --git a/core/src/test/kotlin/ch/dissem/bitmessage/utils/Base64Test.kt b/core/src/test/kotlin/ch/dissem/bitmessage/utils/Base64Test.kt
new file mode 100644
index 0000000..35f9e3a
--- /dev/null
+++ b/core/src/test/kotlin/ch/dissem/bitmessage/utils/Base64Test.kt
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2017 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils
+
+import ch.dissem.bitmessage.cryptography.bc.BouncyCryptography
+import org.hamcrest.Matchers.`is`
+import org.junit.Assert.assertThat
+import org.junit.Test
+
+class Base64Test {
+    @Test
+    fun `ensure data is encoded and decoded correctly`() {
+        val cryptography = BouncyCryptography()
+        for (i in 100..200) {
+            val data = cryptography.randomBytes(i)
+            val string = Base64.encodeToString(data)
+            val decoded = Base64.decode(string)
+            assertThat(decoded, `is`(data))
+        }
+    }
+}
diff --git a/core/src/test/kotlin/ch/dissem/bitmessage/utils/ConversationServiceTest.kt b/core/src/test/kotlin/ch/dissem/bitmessage/utils/ConversationServiceTest.kt
index cb26e5f..f960086 100644
--- a/core/src/test/kotlin/ch/dissem/bitmessage/utils/ConversationServiceTest.kt
+++ b/core/src/test/kotlin/ch/dissem/bitmessage/utils/ConversationServiceTest.kt
@@ -36,6 +36,8 @@ class ConversationServiceTest : TestBase() {
     private val messageRepository = mock<MessageRepository>()
     private val conversationService = spy(ConversationService(messageRepository))
 
+    private val conversation = conversation(alice, bob)
+
     @Test
     fun `ensure conversation is sorted properly`() {
         MockitoKotlin.registerInstanceCreator { UUID.randomUUID() }
@@ -46,8 +48,9 @@ class ConversationServiceTest : TestBase() {
         assertThat(actual, `is`(expected))
     }
 
-    private val conversation: List<Plaintext>
-        get() {
+    companion object {
+        private var timer = 2
+        fun conversation(alice: BitmessageAddress, bob: BitmessageAddress): List<Plaintext> {
             val result = LinkedList<Plaintext>()
 
             val older = plaintext(alice, bob,
@@ -99,19 +102,18 @@ class ConversationServiceTest : TestBase() {
             return result
         }
 
-    private var timer = 2
-
-    private fun plaintext(from: BitmessageAddress, to: BitmessageAddress,
-                          content: ExtendedEncoding, status: Plaintext.Status): Plaintext {
-        val builder = Plaintext.Builder(MSG)
-            .IV(TestUtils.randomInventoryVector())
-            .from(from)
-            .to(to)
-            .message(content)
-            .status(status)
-        if (status !== Plaintext.Status.DRAFT && status !== Plaintext.Status.DOING_PROOF_OF_WORK) {
-            builder.received(5L * ++timer - RANDOM.nextInt(10))
+        fun plaintext(from: BitmessageAddress, to: BitmessageAddress,
+                      content: ExtendedEncoding, status: Plaintext.Status): Plaintext {
+            val builder = Plaintext.Builder(MSG)
+                .IV(TestUtils.randomInventoryVector())
+                .from(from)
+                .to(to)
+                .message(content)
+                .status(status)
+            if (status !== Plaintext.Status.DRAFT && status !== Plaintext.Status.DOING_PROOF_OF_WORK) {
+                builder.received(5L * ++timer - RANDOM.nextInt(10))
+            }
+            return builder.build()
         }
-        return builder.build()
     }
 }
diff --git a/cryptography-bc/src/test/kotlin/ch/dissem/bitmessage/security/CryptographyTest.kt b/cryptography-bc/src/test/kotlin/ch/dissem/bitmessage/security/CryptographyTest.kt
index 1897512..dbd4980 100644
--- a/cryptography-bc/src/test/kotlin/ch/dissem/bitmessage/security/CryptographyTest.kt
+++ b/cryptography-bc/src/test/kotlin/ch/dissem/bitmessage/security/CryptographyTest.kt
@@ -23,10 +23,7 @@ import ch.dissem.bitmessage.entity.valueobject.PrivateKey
 import ch.dissem.bitmessage.exception.InsufficientProofOfWorkException
 import ch.dissem.bitmessage.ports.MultiThreadedPOWEngine
 import ch.dissem.bitmessage.ports.ProofOfWorkEngine
-import ch.dissem.bitmessage.utils.CallbackWaiter
-import ch.dissem.bitmessage.utils.Singleton
-import ch.dissem.bitmessage.utils.TestUtils
-import ch.dissem.bitmessage.utils.UnixTime
+import ch.dissem.bitmessage.utils.*
 import ch.dissem.bitmessage.utils.UnixTime.DAY
 import ch.dissem.bitmessage.utils.UnixTime.MINUTE
 import ch.dissem.bitmessage.utils.UnixTime.now
@@ -34,7 +31,6 @@ import org.hamcrest.CoreMatchers.`is`
 import org.junit.Assert.*
 import org.junit.Test
 import java.io.ByteArrayInputStream
-import java.io.IOException
 import javax.xml.bind.DatatypeConverter
 
 /**
@@ -63,12 +59,12 @@ class CryptographyTest {
     }
 
     @Test
-    fun ensureDoubleHashYieldsSameResultAsHashOfHash() {
+    fun `ensure double hash yields same result as hash of hash`() {
         assertArrayEquals(crypto.sha512(TEST_SHA512), crypto.doubleSha512(TEST_VALUE))
     }
 
-    @Test(expected = IOException::class)
-    fun ensureExceptionForInsufficientProofOfWork() {
+    @Test(expected = InsufficientProofOfWorkException::class)
+    fun `ensure exception for insufficient proof of work`() {
         val objectMessage = ObjectMessage.Builder()
             .nonce(ByteArray(8))
             .expiresTime(UnixTime.now + 28 * DAY)
@@ -79,7 +75,7 @@ class CryptographyTest {
     }
 
     @Test
-    fun testDoProofOfWork() {
+    fun `ensure proof of work is calculated correctly`() {
         TestUtils.mockedInternalContext(
             cryptography = crypto,
             proofOfWorkEngine = MultiThreadedPOWEngine()
@@ -108,7 +104,7 @@ class CryptographyTest {
     }
 
     @Test
-    fun ensureEncryptionAndDecryptionWorks() {
+    fun `ensure encryption and decryption works`() {
         val data = crypto.randomBytes(100)
         val key_e = crypto.randomBytes(32)
         val iv = crypto.randomBytes(16)
@@ -118,7 +114,7 @@ class CryptographyTest {
     }
 
     @Test(expected = IllegalArgumentException::class)
-    fun ensureDecryptionFailsWithInvalidCypherText() {
+    fun `ensure decryption fails with invalid cypher text`() {
         val data = crypto.randomBytes(128)
         val key_e = crypto.randomBytes(32)
         val iv = crypto.randomBytes(16)
@@ -126,7 +122,7 @@ class CryptographyTest {
     }
 
     @Test
-    fun testMultiplication() {
+    fun `ensure multiplication works correctly`() {
         val a = crypto.randomBytes(PrivateKey.PRIVATE_KEY_SIZE)
         val A = crypto.createPublicKey(a)
 
@@ -137,7 +133,7 @@ class CryptographyTest {
     }
 
     @Test
-    fun ensureSignatureIsValid() {
+    fun `ensure signature is valid`() {
         val data = crypto.randomBytes(100)
         val privateKey = PrivateKey(false, 1, 1000, 1000)
         val signature = crypto.getSignature(data, privateKey)
@@ -145,7 +141,7 @@ class CryptographyTest {
     }
 
     @Test
-    fun ensureSignatureIsInvalidForTemperedData() {
+    fun `ensure signature is invalid for tempered data`() {
         val data = crypto.randomBytes(100)
         val privateKey = PrivateKey(false, 1, 1000, 1000)
         val signature = crypto.getSignature(data, privateKey)
diff --git a/exports/build.gradle b/exports/build.gradle
new file mode 100644
index 0000000..718aabb
--- /dev/null
+++ b/exports/build.gradle
@@ -0,0 +1,23 @@
+uploadArchives {
+    repositories {
+        mavenDeployer {
+            pom.project {
+                name 'Jabit Exports'
+                artifactId = 'jabit-exports'
+                description 'Import and export data to JSON files.'
+            }
+        }
+    }
+}
+
+dependencies {
+    compile project(':core')
+    compile 'org.slf4j:slf4j-api'
+    compile 'com.beust:klaxon'
+
+    testCompile 'junit:junit:4.12'
+    testCompile 'org.hamcrest:hamcrest-library:1.3'
+    testCompile 'com.nhaarman:mockito-kotlin:1.5.0'
+    testCompile project(path: ':core', configuration: 'testArtifacts')
+    testCompile project(':cryptography-bc')
+}
diff --git a/exports/src/main/kotlin/ch/dissem/bitmessage/exports/ContactExport.kt b/exports/src/main/kotlin/ch/dissem/bitmessage/exports/ContactExport.kt
new file mode 100644
index 0000000..e429881
--- /dev/null
+++ b/exports/src/main/kotlin/ch/dissem/bitmessage/exports/ContactExport.kt
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2017 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.exports
+
+import ch.dissem.bitmessage.entity.BitmessageAddress
+import ch.dissem.bitmessage.entity.valueobject.PrivateKey
+import ch.dissem.bitmessage.factory.Factory
+import ch.dissem.bitmessage.utils.Base64
+import ch.dissem.bitmessage.utils.Encode
+import com.beust.klaxon.*
+import java.io.ByteArrayInputStream
+import java.io.ByteArrayOutputStream
+
+/**
+ * Exports and imports contacts and identities
+ */
+object ContactExport {
+    fun exportContacts(contacts: List<BitmessageAddress>, includePrivateKey: Boolean = false) = json {
+        array(
+            contacts.map {
+                obj(
+                    "alias" to it.alias,
+                    "address" to it.address,
+                    "chan" to it.isChan,
+                    "subscribed" to it.isSubscribed,
+                    "pubkey" to it.pubkey?.let {
+                        val out = ByteArrayOutputStream()
+                        it.writeUnencrypted(out)
+                        Base64.encodeToString(out.toByteArray())
+                    },
+                    "privateKey" to if (includePrivateKey) {
+                        it.privateKey?.let { Base64.encodeToString(Encode.bytes(it)) }
+                    } else {
+                        null
+                    }
+                )
+            }
+        )
+    }
+
+    fun importContacts(input: JsonArray<*>): List<BitmessageAddress> {
+        return input.filterIsInstance(JsonObject::class.java).map { json ->
+            fun JsonObject.bytes(fieldName: String) = string(fieldName)?.let { Base64.decode(it) }
+            val privateKey = json.bytes("privateKey")?.let { PrivateKey.read(ByteArrayInputStream(it)) }
+            if (privateKey != null) {
+                BitmessageAddress(privateKey)
+            } else {
+                BitmessageAddress(json.string("address") ?: throw IllegalArgumentException("address expected"))
+            }.apply {
+                alias = json.string("alias")
+                isChan = json.boolean("chan") ?: false
+                isSubscribed = json.boolean("subscribed") ?: false
+                pubkey = json.bytes("pubkey")?.let {
+                    Factory.readPubkey(
+                        version = version,
+                        stream = stream,
+                        `is` = ByteArrayInputStream(it),
+                        length = it.size,
+                        encrypted = false
+                    )
+                }
+            }
+        }
+    }
+}
diff --git a/exports/src/main/kotlin/ch/dissem/bitmessage/exports/MessageExport.kt b/exports/src/main/kotlin/ch/dissem/bitmessage/exports/MessageExport.kt
new file mode 100644
index 0000000..72cf35f
--- /dev/null
+++ b/exports/src/main/kotlin/ch/dissem/bitmessage/exports/MessageExport.kt
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2017 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.exports
+
+import ch.dissem.bitmessage.entity.BitmessageAddress
+import ch.dissem.bitmessage.entity.Plaintext
+import ch.dissem.bitmessage.entity.valueobject.InventoryVector
+import ch.dissem.bitmessage.entity.valueobject.Label
+import ch.dissem.bitmessage.utils.Base64
+import ch.dissem.bitmessage.utils.Encode
+import ch.dissem.bitmessage.utils.TTL
+import com.beust.klaxon.*
+import java.util.*
+
+/**
+ * Exports and imports messages and labels
+ */
+object MessageExport {
+    fun exportLabels(labels: List<Label>) = json {
+        array(
+            labels.map {
+                obj(
+                    "label" to it.toString(),
+                    "type" to it.type?.name,
+                    "color" to it.color
+                )
+            }
+        )
+    }
+
+    fun exportMessages(messages: List<Plaintext>) = json {
+        array(messages.map {
+            obj(
+                "type" to it.type.name,
+                "from" to it.from.address,
+                "to" to it.to?.address,
+                "subject" to it.subject,
+                "body" to it.text,
+
+                "conversationId" to it.conversationId.toString(),
+                "msgId" to it.inventoryVector?.hash?.let { Base64.encodeToString(it) },
+                "encoding" to it.encodingCode,
+                "status" to it.status.name,
+                "message" to Base64.encodeToString(it.message),
+                "ackData" to it.ackData?.let { Base64.encodeToString(it) },
+                "ackMessage" to it.ackMessage?.let { Base64.encodeToString(Encode.bytes(it)) },
+                "signature" to it.signature?.let { Base64.encodeToString(it) },
+                "sent" to it.sent,
+                "received" to it.received,
+                "ttl" to it.ttl,
+                "labels" to array(it.labels.map { it.toString() })
+            )
+        })
+    }
+
+    fun importMessages(input: JsonArray<*>, labels: Map<String, Label>): List<Plaintext> {
+        return input.filterIsInstance(JsonObject::class.java).map { json ->
+            fun JsonObject.bytes(fieldName: String) = string(fieldName)?.let { Base64.decode(it) }
+            Plaintext.Builder(Plaintext.Type.valueOf(json.string("type") ?: "MSG"))
+                .from(json.string("from")?.let { BitmessageAddress(it) } ?: throw IllegalArgumentException("'from' address expected"))
+                .to(json.string("to")?.let { BitmessageAddress(it) })
+                .conversation(json.string("conversationId")?.let { UUID.fromString(it) } ?: UUID.randomUUID())
+                .IV(json.bytes("msgId")?.let { InventoryVector(it) })
+                .encoding(json.long("encoding") ?: throw IllegalArgumentException("encoding expected"))
+                .status(json.string("status")?.let { Plaintext.Status.valueOf(it) } ?: throw IllegalArgumentException("status expected"))
+                .message(json.bytes("message") ?: throw IllegalArgumentException("message expected"))
+                .ackData(json.bytes("ackData"))
+                .ackMessage(json.bytes("ackMessage"))
+                .signature(json.bytes("signature"))
+                .sent(json.long("sent"))
+                .received(json.long("received"))
+                .ttl(json.long("ttl") ?: TTL.msg)
+                .labels(
+                    json.array<String>("labels")?.map { labels[it] }?.filterNotNull() ?: emptyList()
+                )
+                .build()
+        }
+    }
+
+    fun importLabels(input: JsonArray<*>): List<Label> {
+        return input.filterIsInstance(JsonObject::class.java).map { json ->
+            Label(
+                label = json.string("label") ?: throw IllegalArgumentException("label expected"),
+                type = json.string("type")?.let { Label.Type.valueOf(it) },
+                color = json.int("color") ?: 0
+            )
+        }
+    }
+
+    fun createLabelMap(labels: List<Label>) = labels.associateBy { it.toString() }
+}
diff --git a/exports/src/test/kotlin/ch/dissem/bitmessage/exports/ContactExportTest.kt b/exports/src/test/kotlin/ch/dissem/bitmessage/exports/ContactExportTest.kt
new file mode 100644
index 0000000..dd3aa5f
--- /dev/null
+++ b/exports/src/test/kotlin/ch/dissem/bitmessage/exports/ContactExportTest.kt
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2017 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.exports
+
+import ch.dissem.bitmessage.cryptography.bc.BouncyCryptography
+import ch.dissem.bitmessage.entity.BitmessageAddress
+import ch.dissem.bitmessage.utils.TestUtils
+import org.hamcrest.CoreMatchers.`is`
+import org.hamcrest.CoreMatchers.nullValue
+import org.junit.Assert.assertThat
+import org.junit.Test
+
+class ContactExportTest {
+
+    init {
+        TestUtils.mockedInternalContext(cryptography = BouncyCryptography())
+    }
+
+    @Test
+    fun `ensure contacts are exported`() {
+        val alice = BitmessageAddress("BM-2cTtkBnb4BUYDndTKun6D9PjtueP2h1bQj")
+        alice.alias = "Alice"
+        alice.isSubscribed = true
+        val contacts = listOf(
+            BitmessageAddress("BM-2cWJ4UFRTCehWuWNsW8fJkAYMxU4S8jxci"),
+            TestUtils.loadContact(),
+            alice
+        )
+        val export = ContactExport.exportContacts(contacts)
+        print(export.toJsonString(true))
+        assertThat(ContactExport.importContacts(export), `is`(contacts))
+    }
+
+    @Test
+    fun `ensure private keys are omitted by default`() {
+        val contacts = listOf(
+            BitmessageAddress.chan(1, "test")
+        )
+        val export = ContactExport.exportContacts(contacts)
+        print(export.toJsonString(true))
+        val import = ContactExport.importContacts(export)
+        assertThat(import.size, `is`(1))
+        assertThat(import[0].isChan, `is`(true))
+        assertThat(import[0].privateKey, `is`(nullValue()))
+    }
+
+    @Test
+    fun `ensure private keys are exported if flag is set`() {
+        val contacts = listOf(
+            BitmessageAddress.chan(1, "test")
+        )
+        val export = ContactExport.exportContacts(contacts, true)
+        print(export.toJsonString(true))
+        val import = ContactExport.importContacts(export)
+        assertThat(import.size, `is`(1))
+        assertThat(import[0].isChan, `is`(true))
+        assertThat(import[0].privateKey, `is`(contacts[0].privateKey))
+    }
+}
diff --git a/exports/src/test/kotlin/ch/dissem/bitmessage/exports/MessageExportTest.kt b/exports/src/test/kotlin/ch/dissem/bitmessage/exports/MessageExportTest.kt
new file mode 100644
index 0000000..04fd799
--- /dev/null
+++ b/exports/src/test/kotlin/ch/dissem/bitmessage/exports/MessageExportTest.kt
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2017 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.exports
+
+import ch.dissem.bitmessage.cryptography.bc.BouncyCryptography
+import ch.dissem.bitmessage.entity.BitmessageAddress
+import ch.dissem.bitmessage.entity.Plaintext
+import ch.dissem.bitmessage.entity.valueobject.Label
+import ch.dissem.bitmessage.utils.ConversationServiceTest
+import ch.dissem.bitmessage.utils.Singleton
+import ch.dissem.bitmessage.utils.TestUtils
+import org.hamcrest.CoreMatchers.`is`
+import org.junit.Assert.assertThat
+import org.junit.Test
+
+class MessageExportTest {
+    val inbox = Label("Inbox", Label.Type.INBOX, 0x0000ff)
+    val outbox = Label("Outbox", Label.Type.OUTBOX, 0x00ff00)
+    val unread = Label("Unread", Label.Type.UNREAD, 0x000000)
+    val trash = Label("Trash", Label.Type.TRASH, 0x555555)
+
+    val labels = listOf(
+        inbox,
+        outbox,
+        unread,
+        trash
+    )
+    val labelMap = MessageExport.createLabelMap(labels)
+
+    init {
+        TestUtils.mockedInternalContext(cryptography = BouncyCryptography())
+    }
+
+    @Test
+    fun `ensure labels are exported`() {
+        val export = MessageExport.exportLabels(labels)
+        print(export.toJsonString(true))
+        assertThat(MessageExport.importLabels(export), `is`(labels))
+    }
+
+    @Test
+    fun `ensure messages are exported`() {
+        val messages = listOf(
+            Plaintext.Builder(Plaintext.Type.MSG)
+                .ackData(Singleton.cryptography().randomBytes(32))
+                .from(BitmessageAddress("BM-2cWJ4UFRTCehWuWNsW8fJkAYMxU4S8jxci"))
+                .to(BitmessageAddress("BM-2DAjcCFrqFrp88FUxExhJ9kPqHdunQmiyn"))
+                .message("Subject", "Message")
+                .status(Plaintext.Status.RECEIVED)
+                .labels(listOf(inbox))
+                .build(),
+            Plaintext.Builder(Plaintext.Type.BROADCAST)
+                .from(BitmessageAddress("BM-2cSqjfJ8xK6UUn5Rw3RpdGQ9RsDkBhWnS8"))
+                .message("Subject", "Message")
+                .labels(listOf(inbox, unread))
+                .status(Plaintext.Status.SENT)
+                .build(),
+            Plaintext.Builder(Plaintext.Type.MSG)
+                .ttl(1)
+                .message("subject", "message")
+                .from(TestUtils.loadIdentity("BM-2cSqjfJ8xK6UUn5Rw3RpdGQ9RsDkBhWnS8"))
+                .to(TestUtils.loadContact())
+                .labels(listOf(trash))
+                .status(Plaintext.Status.SENT_ACKNOWLEDGED)
+                .build(),
+            *ConversationServiceTest.conversation(
+                TestUtils.loadIdentity("BM-2cSqjfJ8xK6UUn5Rw3RpdGQ9RsDkBhWnS8"),
+                TestUtils.loadContact()
+            ).toTypedArray()
+        )
+        val export = MessageExport.exportMessages(messages)
+        print(export.toJsonString(true))
+        assertThat(MessageExport.importMessages(export, labelMap), `is`(messages))
+    }
+}
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 0cf2d0f..65d177a 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Sun Jul 02 11:22:52 CEST 2017
+#Mon Jul 17 06:32:41 CEST 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.0-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.0-all.zip
diff --git a/networking/src/main/kotlin/ch/dissem/bitmessage/networking/nio/NioNetworkHandler.kt b/networking/src/main/kotlin/ch/dissem/bitmessage/networking/nio/NioNetworkHandler.kt
index b926d7d..2bf4c18 100644
--- a/networking/src/main/kotlin/ch/dissem/bitmessage/networking/nio/NioNetworkHandler.kt
+++ b/networking/src/main/kotlin/ch/dissem/bitmessage/networking/nio/NioNetworkHandler.kt
@@ -203,73 +203,77 @@ class NioNetworkHandler : NetworkHandler, InternalContext.ContextHolder {
                 serverChannel.register(selector, OP_ACCEPT, null)
 
                 while (selector.isOpen) {
-                    selector.select(1000)
-                    val keyIterator = selector.selectedKeys().iterator()
-                    while (keyIterator.hasNext()) {
-                        val key = keyIterator.next()
-                        keyIterator.remove()
-                        if (key.attachment() == null) {
-                            try {
-                                if (key.isAcceptable) {
-                                    // handle accept
-                                    try {
-                                        val accepted = (key.channel() as ServerSocketChannel).accept()
-                                        accepted.configureBlocking(false)
-                                        val connection = Connection(ctx, SERVER,
-                                            NetworkAddress(
-                                                time = now,
-                                                stream = 1L,
-                                                socket = accepted.socket()!!
-                                            ),
-                                            requestedObjects, 0
-                                        )
-                                        connections.put(
-                                            connection,
-                                            accepted.register(selector, OP_READ or OP_WRITE, connection)
-                                        )
-                                    } catch (e: AsynchronousCloseException) {
-                                        LOG.trace(e.message)
-                                    } catch (e: IOException) {
-                                        LOG.error(e.message, e)
-                                    }
+                    try {
+                        selector.select(1000)
+                        val keyIterator = selector.selectedKeys().iterator()
+                        while (keyIterator.hasNext()) {
+                            val key = keyIterator.next()
+                            keyIterator.remove()
+                            if (key.attachment() == null) {
+                                try {
+                                    if (key.isAcceptable) {
+                                        // handle accept
+                                        try {
+                                            val accepted = (key.channel() as ServerSocketChannel).accept()
+                                            accepted.configureBlocking(false)
+                                            val connection = Connection(ctx, SERVER,
+                                                NetworkAddress(
+                                                    time = now,
+                                                    stream = 1L,
+                                                    socket = accepted.socket()!!
+                                                ),
+                                                requestedObjects, 0
+                                            )
+                                            connections.put(
+                                                connection,
+                                                accepted.register(selector, OP_READ or OP_WRITE, connection)
+                                            )
+                                        } catch (e: AsynchronousCloseException) {
+                                            LOG.trace(e.message)
+                                        } catch (e: IOException) {
+                                            LOG.error(e.message, e)
+                                        }
 
-                                }
-                            } catch (e: CancelledKeyException) {
-                                LOG.debug(e.message, e)
-                            }
-
-                        } else {
-                            // handle read/write
-                            val channel = key.channel() as SocketChannel
-                            val connection = key.attachment() as Connection
-                            try {
-                                if (key.isConnectable) {
-                                    if (!channel.finishConnect()) {
-                                        continue
                                     }
+                                } catch (e: CancelledKeyException) {
+                                    LOG.debug(e.message, e)
                                 }
-                                if (key.isWritable) {
-                                    write(channel, connection.io)
+
+                            } else {
+                                // handle read/write
+                                val channel = key.channel() as SocketChannel
+                                val connection = key.attachment() as Connection
+                                try {
+                                    if (key.isConnectable) {
+                                        if (!channel.finishConnect()) {
+                                            continue
+                                        }
+                                    }
+                                    if (key.isWritable) {
+                                        write(channel, connection.io)
+                                    }
+                                    if (key.isReadable) {
+                                        read(channel, connection.io)
+                                    }
+                                    if (connection.state == Connection.State.DISCONNECTED) {
+                                        key.interestOps(0)
+                                        channel.close()
+                                    } else if (connection.io.isWritePending) {
+                                        key.interestOps(OP_READ or OP_WRITE)
+                                    } else {
+                                        key.interestOps(OP_READ)
+                                    }
+                                } catch (e: CancelledKeyException) {
+                                    connection.disconnect()
+                                } catch (e: NodeException) {
+                                    connection.disconnect()
+                                } catch (e: IOException) {
+                                    connection.disconnect()
                                 }
-                                if (key.isReadable) {
-                                    read(channel, connection.io)
-                                }
-                                if (connection.state == Connection.State.DISCONNECTED) {
-                                    key.interestOps(0)
-                                    channel.close()
-                                } else if (connection.io.isWritePending) {
-                                    key.interestOps(OP_READ or OP_WRITE)
-                                } else {
-                                    key.interestOps(OP_READ)
-                                }
-                            } catch (e: CancelledKeyException) {
-                                connection.disconnect()
-                            } catch (e: NodeException) {
-                                connection.disconnect()
-                            } catch (e: IOException) {
-                                connection.disconnect()
                             }
                         }
+                    } catch (e: CancelledKeyException) {
+                        LOG.debug(e.message, e)
                     }
                     // set interest ops
                     for ((connection, selectionKey) in connections) {
diff --git a/networking/src/test/kotlin/ch/dissem/bitmessage/networking/NetworkHandlerTest.kt b/networking/src/test/kotlin/ch/dissem/bitmessage/networking/NetworkHandlerTest.kt
index 4eaface..a94cd1f 100644
--- a/networking/src/test/kotlin/ch/dissem/bitmessage/networking/NetworkHandlerTest.kt
+++ b/networking/src/test/kotlin/ch/dissem/bitmessage/networking/NetworkHandlerTest.kt
@@ -233,7 +233,7 @@ class NetworkHandlerTest {
         private val peerAddress = NetworkAddress.Builder().ipv4(127, 0, 0, 1).port(6001).build()
 
         private fun shutdown(ctx: BitmessageContext) {
-            if (!ctx.isRunning) return
+            if (!ctx.isRunning()) return
 
             ctx.shutdown()
             do {
@@ -241,8 +241,7 @@ class NetworkHandlerTest {
                     Thread.sleep(100)
                 } catch (ignore: InterruptedException) {
                 }
-
-            } while (ctx.isRunning)
+            } while (ctx.isRunning())
         }
 
         private fun shutdown(networkHandler: NetworkHandler) {
diff --git a/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcMessageRepository.kt b/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcMessageRepository.kt
index 0717e8e..7ecfbf8 100644
--- a/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcMessageRepository.kt
+++ b/repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcMessageRepository.kt
@@ -20,22 +20,18 @@ import ch.dissem.bitmessage.entity.Plaintext
 import ch.dissem.bitmessage.entity.valueobject.InventoryVector
 import ch.dissem.bitmessage.entity.valueobject.Label
 import ch.dissem.bitmessage.ports.AbstractMessageRepository
+import ch.dissem.bitmessage.ports.AlreadyStoredException
 import ch.dissem.bitmessage.ports.MessageRepository
 import ch.dissem.bitmessage.repository.JdbcHelper.Companion.writeBlob
 import org.slf4j.LoggerFactory
-import java.io.IOException
-import java.sql.Connection
-import java.sql.ResultSet
-import java.sql.SQLException
-import java.sql.Statement
+import java.sql.*
 import java.util.*
 
 class JdbcMessageRepository(private val config: JdbcConfig) : AbstractMessageRepository(), MessageRepository {
 
     override fun findLabels(where: String): List<Label> {
         try {
-            config.getConnection().use {
-                connection ->
+            config.getConnection().use { connection ->
                 return findLabels(connection, where)
             }
         } catch (e: SQLException) {
@@ -51,12 +47,61 @@ class JdbcMessageRepository(private val config: JdbcConfig) : AbstractMessageRep
         } else {
             Label.Type.valueOf(typeName)
         }
-        val label = Label(rs.getString("label"), type, rs.getInt("color"))
+        val label = Label(rs.getString("label"), type, rs.getInt("color"), rs.getInt("ord"))
         label.id = rs.getLong("id")
 
         return label
     }
 
+    override fun save(label: Label) {
+        config.getConnection().use { connection ->
+            if (label.id != null) {
+                connection.prepareStatement("UPDATE Label SET label=?, type=?, color=?, ord=? WHERE id=?").use { ps ->
+                    ps.setString(1, label.toString())
+                    ps.setString(2, label.type?.name)
+                    ps.setInt(3, label.color)
+                    ps.setInt(4, label.ord)
+                    ps.setInt(5, label.id as Int)
+                    ps.executeUpdate()
+                }
+            } else {
+                try {
+                    connection.autoCommit = false
+                    var exists = false
+                    connection.prepareStatement("SELECT COUNT(1) FROM Label WHERE label=?").use { ps ->
+                        ps.setString(1, label.toString())
+                        val rs = ps.executeQuery()
+                        if (rs.next()) {
+                            exists = rs.getInt(1) > 0
+                        }
+                    }
+
+                    if (exists) {
+                        connection.prepareStatement("UPDATE Label SET type=?, color=?, ord=? WHERE label=?").use { ps ->
+                            ps.setString(1, label.type?.name)
+                            ps.setInt(2, label.color)
+                            ps.setInt(3, label.ord)
+                            ps.setString(4, label.toString())
+                            ps.executeUpdate()
+                        }
+                    } else {
+                        connection.prepareStatement("INSERT INTO Label (label, type, color, ord) VALUES (?, ?, ?, ?)").use { ps ->
+                            ps.setString(1, label.toString())
+                            ps.setString(2, label.type?.name)
+                            ps.setInt(3, label.color)
+                            ps.setInt(4, label.ord)
+                            ps.executeUpdate()
+                        }
+                    }
+                    connection.commit()
+                } catch (e: Exception) {
+                    connection.rollback()
+                    throw e
+                }
+            }
+        }
+    }
+
     override fun countUnread(label: Label?): Int {
         val where = if (label == null) {
             ""
@@ -68,7 +113,7 @@ class JdbcMessageRepository(private val config: JdbcConfig) : AbstractMessageRep
         try {
             config.getConnection().use { connection ->
                 connection.createStatement().use { stmt ->
-                    stmt.executeQuery("SELECT count(*) FROM Message WHERE $where").use { rs ->
+                    stmt.executeQuery("SELECT count(1) FROM Message WHERE $where").use { rs ->
                         if (rs.next()) {
                             return rs.getInt(1)
                         }
@@ -127,7 +172,7 @@ class JdbcMessageRepository(private val config: JdbcConfig) : AbstractMessageRep
         val result = ArrayList<Label>()
         try {
             connection.createStatement().use { stmt ->
-                stmt.executeQuery("SELECT id, label, type, color FROM Label WHERE $where").use { rs ->
+                stmt.executeQuery("SELECT id, label, type, color, ord FROM Label WHERE $where").use { rs ->
                     while (rs.next()) {
                         result.add(getLabel(rs))
                     }
@@ -226,11 +271,15 @@ class JdbcMessageRepository(private val config: JdbcConfig) : AbstractMessageRep
             ps.setObject(13, message.nextTry)
             ps.setObject(14, message.conversationId)
 
-            ps.executeUpdate()
-            // get generated id
-            ps.generatedKeys.use { rs ->
-                rs.next()
-                message.id = rs.getLong(1)
+            try {
+                ps.executeUpdate()
+                // get generated id
+                ps.generatedKeys.use { rs ->
+                    rs.next()
+                    message.id = rs.getLong(1)
+                }
+            } catch (e: SQLIntegrityConstraintViolationException) {
+                throw AlreadyStoredException(cause = e)
             }
         }
     }
diff --git a/settings.gradle b/settings.gradle
index 4caa813..59771e2 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -14,4 +14,6 @@ include 'cryptography-sc'
 
 include 'cryptography-bc'
 
-include 'extensions'
\ No newline at end of file
+include 'extensions'
+
+include 'exports'