diff --git a/core/src/main/kotlin/com/r3corda/core/node/ServiceHub.kt b/core/src/main/kotlin/com/r3corda/core/node/ServiceHub.kt
index e436574204..1e6173c08c 100644
--- a/core/src/main/kotlin/com/r3corda/core/node/ServiceHub.kt
+++ b/core/src/main/kotlin/com/r3corda/core/node/ServiceHub.kt
@@ -12,9 +12,8 @@ import java.time.Clock
  * mocked out. This class is useful to pass to chunks of pluggable code that might have need of many different kinds of
  * functionality and you don't want to hard-code which types in the interface.
  *
- * All services exposed to protocols (public view) need to implement [SerializeAsToken] or similar to avoid being serialized in checkpoints.
- *
- * TODO: Split into a public (to contracts etc) and private (to node) view
+ * Any services exposed to protocols (public view) need to implement [SerializeAsToken] or similar to avoid their internal
+ * state from being serialized in checkpoints.
  */
 interface ServiceHub {
     val walletService: WalletService
diff --git a/core/src/main/kotlin/com/r3corda/core/node/services/testing/MockServices.kt b/core/src/main/kotlin/com/r3corda/core/node/services/testing/MockServices.kt
index e67d4d9f1b..48ccb86659 100644
--- a/core/src/main/kotlin/com/r3corda/core/node/services/testing/MockServices.kt
+++ b/core/src/main/kotlin/com/r3corda/core/node/services/testing/MockServices.kt
@@ -10,6 +10,7 @@ import com.r3corda.core.node.services.AttachmentStorage
 import com.r3corda.core.node.services.IdentityService
 import com.r3corda.core.node.services.KeyManagementService
 import com.r3corda.core.node.services.StorageService
+import com.r3corda.core.serialization.SingletonSerializeAsToken
 import com.r3corda.core.utilities.RecordingMap
 import org.slf4j.LoggerFactory
 import java.io.ByteArrayInputStream
@@ -36,7 +37,7 @@ class MockIdentityService(val identities: List<Party>) : IdentityService {
 }
 
 
-class MockKeyManagementService(vararg initialKeys: KeyPair) : KeyManagementService {
+class MockKeyManagementService(vararg initialKeys: KeyPair) : SingletonSerializeAsToken(), KeyManagementService {
     override val keys: MutableMap<PublicKey, PrivateKey>
 
     init {
@@ -88,7 +89,7 @@ class MockStorageService(override val attachments: AttachmentStorage = MockAttac
                          override val myLegalIdentity: Party = Party("Unit test party", myLegalIdentityKey.public),
 // This parameter is for unit tests that want to observe operation details.
                          val recordingAs: (String) -> String = { tableName -> "" })
-: StorageService {
+: SingletonSerializeAsToken(), StorageService {
     protected val tables = HashMap<String, MutableMap<*, *>>()
 
     private fun <K, V> getMapOriginal(tableName: String): MutableMap<K, V> {
diff --git a/core/src/main/kotlin/com/r3corda/core/serialization/Kryo.kt b/core/src/main/kotlin/com/r3corda/core/serialization/Kryo.kt
index 5d4c397e92..39a773add2 100644
--- a/core/src/main/kotlin/com/r3corda/core/serialization/Kryo.kt
+++ b/core/src/main/kotlin/com/r3corda/core/serialization/Kryo.kt
@@ -284,6 +284,8 @@ fun createKryo(k: Kryo = Kryo()): Kryo {
 
         // This ensures a SerializedBytes<Foo> wrapper is written out as just a byte array.
         register(SerializedBytes::class.java, SerializedBytesSerializer)
+
+        addDefaultSerializer(SerializeAsToken::class.java, SerializeAsTokenSerializer<SerializeAsToken>())
     }
 }
 
diff --git a/core/src/main/kotlin/com/r3corda/core/serialization/SerializationToken.kt b/core/src/main/kotlin/com/r3corda/core/serialization/SerializationToken.kt
index 0e2e50418d..9aa1fa4d4d 100644
--- a/core/src/main/kotlin/com/r3corda/core/serialization/SerializationToken.kt
+++ b/core/src/main/kotlin/com/r3corda/core/serialization/SerializationToken.kt
@@ -1,12 +1,10 @@
 package com.r3corda.core.serialization
 
-import com.esotericsoftware.kryo.DefaultSerializer
 import com.esotericsoftware.kryo.Kryo
 import com.esotericsoftware.kryo.KryoException
 import com.esotericsoftware.kryo.Serializer
 import com.esotericsoftware.kryo.io.Input
 import com.esotericsoftware.kryo.io.Output
-import java.lang.ref.WeakReference
 import java.util.*
 
 /**
@@ -23,76 +21,113 @@ import java.util.*
  * they are serialized because they have a lot of internal state that does not serialize (well).
  *
  * This models a similar pattern to the readReplace/writeReplace methods in Java serialization.
- *
- * With Kryo serialisation, these classes should also annotate themselves with <code>@DefaultSerializer</code>.  See below.
- *
  */
 interface SerializeAsToken {
-    val token: SerializationToken
+    fun toToken(context: SerializeAsTokenContext): SerializationToken
 }
 
 /**
  * This represents a token in the serialized stream for an instance of a type that implements [SerializeAsToken]
  */
 interface SerializationToken {
-    fun fromToken(): Any
+    fun fromToken(context: SerializeAsTokenContext): Any
 }
 
 /**
  * A Kryo serializer for [SerializeAsToken] implementations.
  *
- * Annotate the [SerializeAsToken] with <code>@DefaultSerializer(SerializeAsTokenSerializer::class)</code>
+ * This is registered in [createKryo].
  */
 class SerializeAsTokenSerializer<T : SerializeAsToken> : Serializer<T>() {
     override fun write(kryo: Kryo, output: Output, obj: T) {
-        kryo.writeClassAndObject(output, obj.token)
+        kryo.writeClassAndObject(output, obj.toToken(getContext(kryo) ?: throw KryoException("Attempt to write a ${SerializeAsToken::class.simpleName} instance of ${obj.javaClass.name} without initialising a context")))
     }
 
     override fun read(kryo: Kryo, input: Input, type: Class<T>): T {
         val token = (kryo.readClassAndObject(input) as? SerializationToken) ?: throw KryoException("Non-token read for tokenized type: ${type.name}")
-        val fromToken = token.fromToken()
+        val fromToken = token.fromToken(getContext(kryo) ?: throw KryoException("Attempt to read a token for a ${SerializeAsToken::class.simpleName} instance of ${type.name} without initialising a context"))
         if (type.isAssignableFrom(fromToken.javaClass)) {
             return type.cast(fromToken)
         } else {
-            throw KryoException("Token read did not return tokenized type: ${type.name}")
+            throw KryoException("Token read ($token) did not return expected tokenized type: ${type.name}")
+        }
+    }
+
+    companion object {
+        private fun getContext(kryo: Kryo): SerializeAsTokenContext? = kryo.context.get(SerializeAsTokenContext::class.java) as? SerializeAsTokenContext
+
+        fun setContext(kryo: Kryo, context: SerializeAsTokenContext) {
+            kryo.context.put(SerializeAsTokenContext::class.java, context)
+        }
+
+        fun clearContext(kryo: Kryo) {
+            kryo.context.remove(SerializeAsTokenContext::class.java)
         }
     }
 }
 
 /**
- * A class representing a [SerializationToken] for some object that is not serializable but can be re-created or looked up
- * (when deserialized) via a [String] key.
+ * A context for mapping SerializationTokens to/from SerializeAsTokens.
+ *
+ * A context is initialised with an object containing all the instances of [SerializeAsToken] to eagerly register all the tokens.
+ * In our case this can be the [ServiceHub].
+ *
+ * Then it is a case of using the companion object methods on [SerializeAsTokenSerializer] to set and clear context as necessary
+ * on the Kryo instance when serializing to enable/disable tokenization.
  */
-private data class SerializationStringToken(private val key: String, private val className: String) : SerializationToken {
+class SerializeAsTokenContext(toBeTokenized: Any, kryo: Kryo = createKryo()) {
+    internal val tokenToTokenized = HashMap<SerializationToken, SerializeAsToken>()
+    internal var readOnly = false
 
-    constructor(key: String, toBeProxied: SerializeAsStringToken) : this(key, toBeProxied.javaClass.name) {
-        tokenized.put(this, WeakReference(toBeProxied))
+    init {
+        /*
+         * Go ahead and eagerly serialize the object to register all of the tokens in the context.
+         *
+         * This results in the toToken() method getting called for any [SerializeAsStringToken] instances which
+         * are encountered in the object graph as they are serialized by Kryo and will therefore register the token to
+         * object mapping for those instances.  We then immediately set the readOnly flag to stop further adhoc or
+         * accidental registrations from occuring as these could not be deserialized in a deserialization-first
+         * scenario if they are not part of this iniital context construction serialization.
+         */
+        SerializeAsTokenSerializer.setContext(kryo, this)
+        toBeTokenized.serialize(kryo)
+        SerializeAsTokenSerializer.clearContext(kryo)
+        readOnly = true
     }
+}
+
+/**
+ * A class representing a [SerializationToken] for some object that is not serializable but can be looked up
+ * (when deserialized) via just the class name.
+ */
+data class SingletonSerializationToken private constructor(private val className: String) : SerializationToken {
+
+    constructor(toBeTokenized: SerializeAsToken) : this(toBeTokenized.javaClass.name)
+
+    override fun fromToken(context: SerializeAsTokenContext): Any = context.tokenToTokenized[this] ?:
+            throw IllegalStateException("Unable to find tokenized instance of ${className} in context $context")
 
     companion object {
-        val tokenized = Collections.synchronizedMap(WeakHashMap<SerializationStringToken, WeakReference<SerializeAsStringToken>>())
-    }
+        fun registerWithContext(token: SingletonSerializationToken, toBeTokenized: SerializeAsToken, context: SerializeAsTokenContext): SerializationToken =
+                if (token in context.tokenToTokenized) token else registerNewToken(token, toBeTokenized, context)
 
-    override fun fromToken(): Any = tokenized.get(this)?.get() ?:
-            throw IllegalStateException("Unable to find tokenized instance of ${className} for key $key")
+        // Only allowable if we are in SerializeAsTokenContext init (readOnly == false)
+        private fun registerNewToken(token: SingletonSerializationToken, toBeTokenized: SerializeAsToken, context: SerializeAsTokenContext): SerializationToken {
+            if (context.readOnly) throw UnsupportedOperationException("Attempt to write token for lazy registered ${toBeTokenized.javaClass.name}. " +
+                    "All tokens should be registered during context construction.")
+            context.tokenToTokenized[token] = toBeTokenized
+            return token
+        }
+    }
 }
 
 /**
  * A base class for implementing large objects / components / services that need to serialize themselves to a string token
  * to indicate which instance the token is a serialized form of.
- *
- * This class will also double check that the class is annotated for Kryo serialization.  Note it does this on every
- * instance constructed but given this is designed to represent heavyweight services or components, this should not be significant.
  */
-abstract class SerializeAsStringToken(val key: String) : SerializeAsToken {
+abstract class SingletonSerializeAsToken() : SerializeAsToken {
 
-    init {
-        // Verify we have the annotation
-        val annotation = javaClass.getAnnotation(DefaultSerializer::class.java)
-        if (annotation == null || annotation.value.java.name != SerializeAsTokenSerializer::class.java.name) {
-            throw IllegalStateException("${this.javaClass.name} is not annotated with @${DefaultSerializer::class.java.simpleName} set to ${SerializeAsTokenSerializer::class.java.simpleName}")
-        }
-    }
+    private val token = SingletonSerializationToken(this)
 
-    override val token: SerializationToken = SerializationStringToken(key, this)
+    override fun toToken(context: SerializeAsTokenContext) = SingletonSerializationToken.registerWithContext(token, this, context)
 }
\ No newline at end of file
diff --git a/core/src/test/kotlin/com/r3corda/core/serialization/SerializationTokenTest.kt b/core/src/test/kotlin/com/r3corda/core/serialization/SerializationTokenTest.kt
index 786bc62601..44f27702e8 100644
--- a/core/src/test/kotlin/com/r3corda/core/serialization/SerializationTokenTest.kt
+++ b/core/src/test/kotlin/com/r3corda/core/serialization/SerializationTokenTest.kt
@@ -1,17 +1,34 @@
 package com.r3corda.core.serialization
 
-import com.esotericsoftware.kryo.DefaultSerializer
+import com.esotericsoftware.kryo.Kryo
+import com.esotericsoftware.kryo.KryoException
+import com.esotericsoftware.kryo.io.Output
 import org.assertj.core.api.Assertions.assertThat
+import org.junit.After
+import org.junit.Before
 import org.junit.Test
-import kotlin.test.assertEquals
-import kotlin.test.assertNotEquals
+import java.io.ByteArrayOutputStream
 
 class SerializationTokenTest {
 
+    lateinit var kryo: Kryo
+
+    @Before
+    fun setup() {
+        kryo = THREAD_LOCAL_KRYO.get()
+    }
+
+    @After
+    fun cleanup() {
+        SerializeAsTokenSerializer.clearContext(kryo)
+    }
+
     // Large tokenizable object so we can tell from the smaller number of serialized bytes it was actually tokenized
-    @DefaultSerializer(SerializeAsTokenSerializer::class)
-    private class LargeTokenizable(size: Int) : SerializeAsStringToken(size.toString()) {
-        val bytes = OpaqueBytes(ByteArray(size))
+    private class LargeTokenizable : SingletonSerializeAsToken() {
+        val bytes = OpaqueBytes(ByteArray(1024))
+
+        val numBytes: Int
+            get() = bytes.size
 
         override fun hashCode() = bytes.bits.size
 
@@ -20,61 +37,78 @@ class SerializationTokenTest {
 
     @Test
     fun `write token and read tokenizable`() {
-        val numBytes = 1024
-        val tokenizableBefore = LargeTokenizable(numBytes)
-        val serializedBytes = tokenizableBefore.serialize()
-        assertThat(serializedBytes.size).isLessThan(numBytes)
-        val tokenizableAfter = serializedBytes.deserialize()
-        assertEquals(tokenizableBefore, tokenizableAfter)
-    }
-
-    @Test
-    fun `check same sized tokenizable equal`() {
-        val tokenizableBefore = LargeTokenizable(1024)
-        val tokenizableAfter = LargeTokenizable(1024)
-        assertEquals(tokenizableBefore, tokenizableAfter)
-    }
-
-    @Test
-    fun `check different sized tokenizable not equal`() {
-        val tokenizableBefore = LargeTokenizable(1024)
-        val tokenizableAfter = LargeTokenizable(1025)
-        assertNotEquals(tokenizableBefore, tokenizableAfter)
-    }
-
-    @DefaultSerializer(SerializeAsTokenSerializer::class)
-    private class IntegerSerializeAsKeyedToken(val value: Int) : SerializeAsStringToken(value.toString())
-
-    @Test
-    fun `write and read keyed`() {
-        val tokenizableBefore1 = IntegerSerializeAsKeyedToken(123)
-        val tokenizableBefore2 = IntegerSerializeAsKeyedToken(456)
-
-        val serializedBytes1 = tokenizableBefore1.serialize()
-        val tokenizableAfter1 = serializedBytes1.deserialize()
-        val serializedBytes2 = tokenizableBefore2.serialize()
-        val tokenizableAfter2 = serializedBytes2.deserialize()
-
-        assertThat(tokenizableAfter1).isSameAs(tokenizableBefore1)
-        assertThat(tokenizableAfter2).isSameAs(tokenizableBefore2)
-    }
-
-    @DefaultSerializer(SerializeAsTokenSerializer::class)
-    private class UnitSerializeAsSingletonToken : SerializeAsStringToken("Unit0")
-
-    @Test
-    fun `write and read singleton`() {
-        val tokenizableBefore = UnitSerializeAsSingletonToken()
-        val serializedBytes = tokenizableBefore.serialize()
-        val tokenizableAfter = serializedBytes.deserialize()
+        val tokenizableBefore = LargeTokenizable()
+        val context = SerializeAsTokenContext(tokenizableBefore, kryo)
+        SerializeAsTokenSerializer.setContext(kryo, context)
+        val serializedBytes = tokenizableBefore.serialize(kryo)
+        assertThat(serializedBytes.size).isLessThan(tokenizableBefore.numBytes)
+        val tokenizableAfter = serializedBytes.deserialize(kryo)
         assertThat(tokenizableAfter).isSameAs(tokenizableBefore)
     }
 
-    private class UnannotatedSerializeAsSingletonToken : SerializeAsStringToken("Unannotated0")
+    private class UnitSerializeAsToken : SingletonSerializeAsToken()
 
-    @Test(expected = IllegalStateException::class)
-    fun `unannotated throws`() {
-        @Suppress("UNUSED_VARIABLE")
-        val tokenizableBefore = UnannotatedSerializeAsSingletonToken()
+    @Test
+    fun `write and read singleton`() {
+        val tokenizableBefore = UnitSerializeAsToken()
+        val context = SerializeAsTokenContext(tokenizableBefore, kryo)
+        SerializeAsTokenSerializer.setContext(kryo, context)
+        val serializedBytes = tokenizableBefore.serialize(kryo)
+        val tokenizableAfter = serializedBytes.deserialize(kryo)
+        assertThat(tokenizableAfter).isSameAs(tokenizableBefore)
+    }
+
+    @Test(expected = UnsupportedOperationException::class)
+    fun `new token encountered after context init`() {
+        val tokenizableBefore = UnitSerializeAsToken()
+        val context = SerializeAsTokenContext(emptyList<Any>(), kryo)
+        SerializeAsTokenSerializer.setContext(kryo, context)
+        tokenizableBefore.serialize(kryo)
+    }
+
+    @Test(expected = UnsupportedOperationException::class)
+    fun `deserialize unregistered token`() {
+        val tokenizableBefore = UnitSerializeAsToken()
+        val context = SerializeAsTokenContext(emptyList<Any>(), kryo)
+        SerializeAsTokenSerializer.setContext(kryo, context)
+        val serializedBytes = tokenizableBefore.toToken(SerializeAsTokenContext(emptyList<Any>(), kryo)).serialize(kryo)
+        serializedBytes.deserialize(kryo)
+    }
+
+    @Test(expected = KryoException::class)
+    fun `no context set`() {
+        val tokenizableBefore = UnitSerializeAsToken()
+        tokenizableBefore.serialize(kryo)
+    }
+
+    @Test(expected = KryoException::class)
+    fun `deserialize non-token`() {
+        val tokenizableBefore = UnitSerializeAsToken()
+        val context = SerializeAsTokenContext(tokenizableBefore, kryo)
+        SerializeAsTokenSerializer.setContext(kryo, context)
+        val stream = ByteArrayOutputStream()
+        Output(stream).use {
+            kryo.writeClass(it, SingletonSerializeAsToken::class.java)
+            kryo.writeObject(it, emptyList<Any>())
+        }
+        val serializedBytes = SerializedBytes<Any>(stream.toByteArray())
+        serializedBytes.deserialize(kryo)
+    }
+
+    private class WrongTypeSerializeAsToken : SerializeAsToken {
+        override fun toToken(context: SerializeAsTokenContext): SerializationToken {
+            return object : SerializationToken {
+                override fun fromToken(context: SerializeAsTokenContext): Any = UnitSerializeAsToken()
+            }
+        }
+    }
+
+    @Test(expected = KryoException::class)
+    fun `token returns unexpected type`() {
+        val tokenizableBefore = WrongTypeSerializeAsToken()
+        val context = SerializeAsTokenContext(tokenizableBefore, kryo)
+        SerializeAsTokenSerializer.setContext(kryo, context)
+        val serializedBytes = tokenizableBefore.serialize(kryo)
+        serializedBytes.deserialize(kryo)
     }
 }
\ No newline at end of file
diff --git a/node/src/main/kotlin/com/r3corda/node/internal/Node.kt b/node/src/main/kotlin/com/r3corda/node/internal/Node.kt
index 0c51a7470a..7ce76b0e18 100644
--- a/node/src/main/kotlin/com/r3corda/node/internal/Node.kt
+++ b/node/src/main/kotlin/com/r3corda/node/internal/Node.kt
@@ -7,6 +7,7 @@ import com.r3corda.core.node.NodeInfo
 import com.r3corda.core.node.services.ServiceType
 import com.r3corda.core.utilities.loggerFor
 import com.r3corda.node.api.APIServer
+import com.r3corda.node.serialization.NodeClock
 import com.r3corda.node.services.config.NodeConfiguration
 import com.r3corda.node.services.messaging.ArtemisMessagingService
 import com.r3corda.node.servlets.AttachmentDownloadServlet
@@ -52,7 +53,7 @@ class ConfigurationException(message: String) : Exception(message)
  */
 class Node(dir: Path, val p2pAddr: HostAndPort, configuration: NodeConfiguration,
            networkMapAddress: NodeInfo?, advertisedServices: Set<ServiceType>,
-           clock: Clock = Clock.systemUTC(),
+           clock: Clock = NodeClock(),
            val clientAPIs: List<Class<*>> = listOf()) : AbstractNode(dir, configuration, networkMapAddress, advertisedServices, clock) {
     companion object {
         /** The port that is used by default if none is specified. As you know, 31337 is the most elite number. */
diff --git a/node/src/main/kotlin/com/r3corda/node/internal/testing/MockNode.kt b/node/src/main/kotlin/com/r3corda/node/internal/testing/MockNode.kt
index be3f5d3287..64573a7c1a 100644
--- a/node/src/main/kotlin/com/r3corda/node/internal/testing/MockNode.kt
+++ b/node/src/main/kotlin/com/r3corda/node/internal/testing/MockNode.kt
@@ -12,6 +12,7 @@ import com.r3corda.core.node.services.ServiceType
 import com.r3corda.core.node.services.testing.MockIdentityService
 import com.r3corda.core.utilities.loggerFor
 import com.r3corda.node.internal.AbstractNode
+import com.r3corda.node.serialization.NodeClock
 import com.r3corda.node.services.config.NodeConfiguration
 import com.r3corda.node.services.network.InMemoryMessagingNetwork
 import com.r3corda.node.services.network.NetworkMapService
@@ -21,7 +22,6 @@ import org.slf4j.Logger
 import java.nio.file.Files
 import java.nio.file.Path
 import java.security.KeyPair
-import java.time.Clock
 import java.util.*
 
 /**
@@ -66,7 +66,7 @@ class MockNetwork(private val threadPerNode: Boolean = false,
     }
 
     open class MockNode(dir: Path, config: NodeConfiguration, val mockNet: MockNetwork, networkMapAddr: NodeInfo?,
-                        advertisedServices: Set<ServiceType>, val id: Int, val keyPair: KeyPair?) : AbstractNode(dir, config, networkMapAddr, advertisedServices, Clock.systemUTC()) {
+                        advertisedServices: Set<ServiceType>, val id: Int, val keyPair: KeyPair?) : AbstractNode(dir, config, networkMapAddr, advertisedServices, NodeClock()) {
         override val log: Logger = loggerFor<MockNode>()
         override val serverThread: AffinityExecutor =
                 if (mockNet.threadPerNode)
diff --git a/node/src/main/kotlin/com/r3corda/node/serialization/NodeClock.kt b/node/src/main/kotlin/com/r3corda/node/serialization/NodeClock.kt
new file mode 100644
index 0000000000..a7ca24fd3f
--- /dev/null
+++ b/node/src/main/kotlin/com/r3corda/node/serialization/NodeClock.kt
@@ -0,0 +1,35 @@
+package com.r3corda.node.serialization
+
+import com.r3corda.core.serialization.SerializeAsToken
+import com.r3corda.core.serialization.SerializeAsTokenContext
+import com.r3corda.core.serialization.SingletonSerializationToken
+import java.time.Clock
+import java.time.Instant
+import java.time.ZoneId
+import javax.annotation.concurrent.ThreadSafe
+
+
+/**
+ * A [Clock] that tokenizes itself when serialized, and delegates to an underlying [Clock] implementation.
+ */
+@ThreadSafe
+class NodeClock(private val delegateClock: Clock = Clock.systemUTC()) : Clock(), SerializeAsToken {
+
+    private val token = SingletonSerializationToken(this)
+
+    override fun toToken(context: SerializeAsTokenContext) = SingletonSerializationToken.registerWithContext(token, this, context)
+
+    override fun instant(): Instant {
+        return delegateClock.instant()
+    }
+
+    // Do not use this. Instead seek to use ZonedDateTime methods.
+    override fun withZone(zone: ZoneId): Clock {
+        throw UnsupportedOperationException("Tokenized clock does not support withZone()")
+    }
+
+    override fun getZone(): ZoneId {
+        return delegateClock.zone
+    }
+
+}
\ No newline at end of file
diff --git a/node/src/main/kotlin/com/r3corda/node/services/api/MonitoringService.kt b/node/src/main/kotlin/com/r3corda/node/services/api/MonitoringService.kt
index 3b7fd2a2dc..97d84b8b79 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/api/MonitoringService.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/api/MonitoringService.kt
@@ -1,10 +1,11 @@
 package com.r3corda.node.services.api
 
 import com.codahale.metrics.MetricRegistry
+import com.r3corda.core.serialization.SingletonSerializeAsToken
 
 
 /**
  * Provides access to various metrics and ways to notify monitoring services of things, for sysadmin purposes.
  * This is not an interface because it is too lightweight to bother mocking out.
  */
-class MonitoringService(val metrics: MetricRegistry)
\ No newline at end of file
+class MonitoringService(val metrics: MetricRegistry) : SingletonSerializeAsToken()
\ No newline at end of file
diff --git a/node/src/main/kotlin/com/r3corda/node/services/identity/InMemoryIdentityService.kt b/node/src/main/kotlin/com/r3corda/node/services/identity/InMemoryIdentityService.kt
index d245b9f5b9..243dbda4c9 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/identity/InMemoryIdentityService.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/identity/InMemoryIdentityService.kt
@@ -2,6 +2,7 @@ package com.r3corda.node.services.identity
 
 import com.r3corda.core.crypto.Party
 import com.r3corda.core.node.services.IdentityService
+import com.r3corda.core.serialization.SingletonSerializeAsToken
 import java.security.PublicKey
 import java.util.concurrent.ConcurrentHashMap
 import javax.annotation.concurrent.ThreadSafe
@@ -10,7 +11,7 @@ import javax.annotation.concurrent.ThreadSafe
  * Simple identity service which caches parties and provides functionality for efficient lookup.
  */
 @ThreadSafe
-class InMemoryIdentityService() : IdentityService {
+class InMemoryIdentityService() : SingletonSerializeAsToken(), IdentityService {
     private val keyToParties = ConcurrentHashMap<PublicKey, Party>()
     private val nameToParties = ConcurrentHashMap<String, Party>()
 
diff --git a/node/src/main/kotlin/com/r3corda/node/services/keys/E2ETestKeyManagementService.kt b/node/src/main/kotlin/com/r3corda/node/services/keys/E2ETestKeyManagementService.kt
index b3528b4138..05c4247caf 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/keys/E2ETestKeyManagementService.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/keys/E2ETestKeyManagementService.kt
@@ -3,6 +3,7 @@ package com.r3corda.node.services.keys
 import com.r3corda.core.ThreadBox
 import com.r3corda.core.crypto.generateKeyPair
 import com.r3corda.core.node.services.KeyManagementService
+import com.r3corda.core.serialization.SingletonSerializeAsToken
 import java.security.KeyPair
 import java.security.PrivateKey
 import java.security.PublicKey
@@ -21,7 +22,7 @@ import javax.annotation.concurrent.ThreadSafe
  * etc
  */
 @ThreadSafe
-class E2ETestKeyManagementService : KeyManagementService {
+class E2ETestKeyManagementService() : SingletonSerializeAsToken(), KeyManagementService {
     private class InnerState {
         val keys = HashMap<PublicKey, PrivateKey>()
     }
diff --git a/node/src/main/kotlin/com/r3corda/node/services/messaging/ArtemisMessagingService.kt b/node/src/main/kotlin/com/r3corda/node/services/messaging/ArtemisMessagingService.kt
index d99485fe91..479d89c210 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/messaging/ArtemisMessagingService.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/messaging/ArtemisMessagingService.kt
@@ -4,8 +4,9 @@ import com.google.common.net.HostAndPort
 import com.r3corda.core.RunOnCallerThread
 import com.r3corda.core.ThreadBox
 import com.r3corda.core.messaging.*
-import com.r3corda.node.internal.Node
+import com.r3corda.core.serialization.SingletonSerializeAsToken
 import com.r3corda.core.utilities.loggerFor
+import com.r3corda.node.internal.Node
 import org.apache.activemq.artemis.api.core.SimpleString
 import org.apache.activemq.artemis.api.core.TransportConfiguration
 import org.apache.activemq.artemis.api.core.client.*
@@ -52,7 +53,7 @@ import javax.annotation.concurrent.ThreadSafe
  */
 @ThreadSafe
 class ArtemisMessagingService(val directory: Path, val myHostPort: HostAndPort,
-                              val defaultExecutor: Executor = RunOnCallerThread) : MessagingService {
+                              val defaultExecutor: Executor = RunOnCallerThread) : SingletonSerializeAsToken(), MessagingService {
     // In future: can contain onion routing info, etc.
     private data class Address(val hostAndPort: HostAndPort) : SingleMessageRecipient
 
diff --git a/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryMessagingNetwork.kt b/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryMessagingNetwork.kt
index 03192a4b53..fa5e61e6f0 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryMessagingNetwork.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryMessagingNetwork.kt
@@ -6,6 +6,7 @@ import com.google.common.util.concurrent.MoreExecutors
 import com.r3corda.core.ThreadBox
 import com.r3corda.core.crypto.sha256
 import com.r3corda.core.messaging.*
+import com.r3corda.core.serialization.SingletonSerializeAsToken
 import com.r3corda.core.utilities.loggerFor
 import com.r3corda.core.utilities.trace
 import org.slf4j.LoggerFactory
@@ -28,7 +29,7 @@ import kotlin.concurrent.thread
  * testing).
  */
 @ThreadSafe
-class InMemoryMessagingNetwork {
+class InMemoryMessagingNetwork() : SingletonSerializeAsToken() {
     companion object {
         val MESSAGES_LOG_NAME = "messages"
         private val log = LoggerFactory.getLogger(MESSAGES_LOG_NAME)
@@ -167,7 +168,7 @@ class InMemoryMessagingNetwork {
      * An instance can be obtained by creating a builder and then using the start method.
      */
     @ThreadSafe
-    inner class InMemoryMessaging(private val manuallyPumped: Boolean, private val handle: Handle) : MessagingService {
+    inner class InMemoryMessaging(private val manuallyPumped: Boolean, private val handle: Handle) : SingletonSerializeAsToken(), MessagingService {
         inner class Handler(val executor: Executor?, val topic: String,
                             val callback: (Message, MessageHandlerRegistration) -> Unit) : MessageHandlerRegistration
 
diff --git a/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryNetworkMapCache.kt b/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryNetworkMapCache.kt
index 8fb9f2ae74..6c182f2988 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryNetworkMapCache.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/network/InMemoryNetworkMapCache.kt
@@ -15,6 +15,7 @@ import com.r3corda.core.node.services.NetworkMapCache
 import com.r3corda.core.node.services.ServiceType
 import com.r3corda.core.node.services.TOPIC_DEFAULT_POSTFIX
 import com.r3corda.core.random63BitValue
+import com.r3corda.core.serialization.SingletonSerializeAsToken
 import com.r3corda.core.serialization.deserialize
 import com.r3corda.core.serialization.serialize
 import com.r3corda.node.services.api.RegulatorService
@@ -30,7 +31,7 @@ import javax.annotation.concurrent.ThreadSafe
  * Extremely simple in-memory cache of the network map.
  */
 @ThreadSafe
-open class InMemoryNetworkMapCache() : NetworkMapCache {
+open class InMemoryNetworkMapCache() : SingletonSerializeAsToken(), NetworkMapCache {
     override val networkMapNodes: List<NodeInfo>
         get() = get(NetworkMapService.Type)
     override val regulators: List<NodeInfo>
diff --git a/node/src/main/kotlin/com/r3corda/node/services/network/MockNetworkMapCache.kt b/node/src/main/kotlin/com/r3corda/node/services/network/MockNetworkMapCache.kt
index 4c9e1751c8..a59c936e5a 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/network/MockNetworkMapCache.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/network/MockNetworkMapCache.kt
@@ -1,15 +1,8 @@
-/*
- * Copyright 2016 Distributed Ledger Group LLC.  Distributed as Licensed Company IP to DLG Group Members
- * pursuant to the August 7, 2015 Advisory Services Agreement and subject to the Company IP License terms
- * set forth therein.
- *
- * All other rights reserved.
- */
 package com.r3corda.node.services.network
 
 import co.paralleluniverse.common.util.VisibleForTesting
-import com.r3corda.core.crypto.Party
 import com.r3corda.core.crypto.DummyPublicKey
+import com.r3corda.core.crypto.Party
 import com.r3corda.core.messaging.SingleMessageRecipient
 import com.r3corda.core.node.NodeInfo
 
diff --git a/node/src/main/kotlin/com/r3corda/node/services/persistence/StorageServiceImpl.kt b/node/src/main/kotlin/com/r3corda/node/services/persistence/StorageServiceImpl.kt
index 3c81f85ae8..86a485773e 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/persistence/StorageServiceImpl.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/persistence/StorageServiceImpl.kt
@@ -1,10 +1,11 @@
 package com.r3corda.node.services.persistence
 
-import com.r3corda.core.crypto.Party
 import com.r3corda.core.contracts.SignedTransaction
+import com.r3corda.core.crypto.Party
 import com.r3corda.core.crypto.SecureHash
 import com.r3corda.core.node.services.AttachmentStorage
 import com.r3corda.core.node.services.StorageService
+import com.r3corda.core.serialization.SingletonSerializeAsToken
 import com.r3corda.core.utilities.RecordingMap
 import org.slf4j.LoggerFactory
 import java.security.KeyPair
@@ -15,7 +16,7 @@ open class StorageServiceImpl(override val attachments: AttachmentStorage,
                               override val myLegalIdentity: Party = Party("Unit test party", myLegalIdentityKey.public),
                               // This parameter is for unit tests that want to observe operation details.
                               val recordingAs: (String) -> String = { tableName -> "" })
-: StorageService {
+: SingletonSerializeAsToken(), StorageService {
     protected val tables = HashMap<String, MutableMap<*, *>>()
 
     private fun <K, V> getMapOriginal(tableName: String): MutableMap<K, V> {
diff --git a/node/src/main/kotlin/com/r3corda/node/services/statemachine/ProtocolStateMachineImpl.kt b/node/src/main/kotlin/com/r3corda/node/services/statemachine/ProtocolStateMachineImpl.kt
index 3233daf20f..e4120e96d9 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/statemachine/ProtocolStateMachineImpl.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/statemachine/ProtocolStateMachineImpl.kt
@@ -3,17 +3,11 @@ package com.r3corda.node.services.statemachine
 import co.paralleluniverse.fibers.Fiber
 import co.paralleluniverse.fibers.FiberScheduler
 import co.paralleluniverse.fibers.Suspendable
-import co.paralleluniverse.io.serialization.kryo.KryoSerializer
 import com.google.common.util.concurrent.ListenableFuture
 import com.google.common.util.concurrent.SettableFuture
 import com.r3corda.core.messaging.MessageRecipients
-import com.r3corda.node.services.statemachine.StateMachineManager
-import com.r3corda.core.node.ServiceHub
 import com.r3corda.core.protocols.ProtocolLogic
 import com.r3corda.core.protocols.ProtocolStateMachine
-import com.r3corda.core.serialization.SerializedBytes
-import com.r3corda.core.serialization.createKryo
-import com.r3corda.core.serialization.serialize
 import com.r3corda.core.utilities.UntrustworthyData
 import com.r3corda.node.services.api.ServiceHubInternal
 import org.slf4j.Logger
@@ -30,7 +24,7 @@ import org.slf4j.LoggerFactory
 class ProtocolStateMachineImpl<R>(val logic: ProtocolLogic<R>, scheduler: FiberScheduler, val loggerName: String) : Fiber<R>("protocol", scheduler), ProtocolStateMachine<R> {
 
     // These fields shouldn't be serialised, so they are marked @Transient.
-    @Transient private var suspendAction: ((result: StateMachineManager.FiberRequest, serialisedFiber: SerializedBytes<ProtocolStateMachineImpl<*>>) -> Unit)? = null
+    @Transient private var suspendAction: ((result: StateMachineManager.FiberRequest, fiber: ProtocolStateMachineImpl<*>) -> Unit)? = null
     @Transient private var resumeWithObject: Any? = null
     @Transient lateinit override var serviceHub: ServiceHubInternal
 
@@ -59,7 +53,7 @@ class ProtocolStateMachineImpl<R>(val logic: ProtocolLogic<R>, scheduler: FiberS
 
     fun prepareForResumeWith(serviceHub: ServiceHubInternal,
                              withObject: Any?,
-                             suspendAction: (StateMachineManager.FiberRequest, SerializedBytes<ProtocolStateMachineImpl<*>>) -> Unit) {
+                             suspendAction: (StateMachineManager.FiberRequest, ProtocolStateMachineImpl<*>) -> Unit) {
         this.suspendAction = suspendAction
         this.resumeWithObject = withObject
         this.serviceHub = serviceHub
@@ -108,10 +102,7 @@ class ProtocolStateMachineImpl<R>(val logic: ProtocolLogic<R>, scheduler: FiberS
     @Suspendable
     private fun suspend(with: StateMachineManager.FiberRequest) {
         parkAndSerialize { fiber, serializer ->
-            // We don't use the passed-in serializer here, because we need to use our own augmented Kryo.
-            val deserializer = getFiberSerializer(false) as KryoSerializer
-            val kryo = createKryo(deserializer.kryo)
-            suspendAction!!(with, this.serialize(kryo))
+            suspendAction!!(with, this)
         }
     }
 
diff --git a/node/src/main/kotlin/com/r3corda/node/services/statemachine/StateMachineManager.kt b/node/src/main/kotlin/com/r3corda/node/services/statemachine/StateMachineManager.kt
index 506d8a038a..319c03897c 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/statemachine/StateMachineManager.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/statemachine/StateMachineManager.kt
@@ -12,10 +12,7 @@ import com.r3corda.core.messaging.runOnNextMessage
 import com.r3corda.core.messaging.send
 import com.r3corda.core.protocols.ProtocolLogic
 import com.r3corda.core.protocols.ProtocolStateMachine
-import com.r3corda.core.serialization.SerializedBytes
-import com.r3corda.core.serialization.THREAD_LOCAL_KRYO
-import com.r3corda.core.serialization.createKryo
-import com.r3corda.core.serialization.deserialize
+import com.r3corda.core.serialization.*
 import com.r3corda.core.then
 import com.r3corda.core.utilities.ProgressTracker
 import com.r3corda.core.utilities.trace
@@ -51,8 +48,6 @@ import javax.annotation.concurrent.ThreadSafe
  * TODO: Timeouts
  * TODO: Surfacing of exceptions via an API and/or management UI
  * TODO: Ability to control checkpointing explicitly, for cases where you know replaying a message can't hurt
- * TODO: Make Kryo (de)serialize markers for heavy objects that are currently in the service hub. This avoids mistakes
- *       where services are temporarily put on the stack.
  * TODO: Implement stub/skel classes that provide a basic RPC framework on top of this.
  */
 @ThreadSafe
@@ -76,6 +71,9 @@ class StateMachineManager(val serviceHub: ServiceHubInternal, val checkpointStor
     private val totalStartedProtocols = metrics.counter("Protocols.Started")
     private val totalFinishedProtocols = metrics.counter("Protocols.Finished")
 
+    // Context for tokenized services in checkpoints
+    private val serializationContext = SerializeAsTokenContext(serviceHub)
+
     /** Returns a list of all state machines executing the given protocol logic at the top level (subprotocols do not count) */
     fun <T> findStateMachines(klass: Class<out ProtocolLogic<T>>): List<Pair<ProtocolLogic<T>, ListenableFuture<T>>> {
         synchronized(stateMachines) {
@@ -139,6 +137,8 @@ class StateMachineManager(val serviceHub: ServiceHubInternal, val checkpointStor
     private fun deserializeFiber(serialisedFiber: SerializedBytes<out ProtocolStateMachine<*>>): ProtocolStateMachineImpl<*> {
         val deserializer = Fiber.getFiberSerializer(false) as KryoSerializer
         val kryo = createKryo(deserializer.kryo)
+        // put the map of token -> tokenized into the kryo context
+        SerializeAsTokenSerializer.setContext(kryo, serializationContext)
         return serialisedFiber.deserialize(kryo) as ProtocolStateMachineImpl<*>
     }
 
@@ -202,9 +202,15 @@ class StateMachineManager(val serviceHub: ServiceHubInternal, val checkpointStor
                                     obj: Any?,
                                     resumeFunc: (ProtocolStateMachineImpl<*>) -> Unit) {
         executor.checkOnThread()
-        val onSuspend = fun(request: FiberRequest, serialisedFiber: SerializedBytes<ProtocolStateMachineImpl<*>>) {
+        val onSuspend = fun(request: FiberRequest, fiber: ProtocolStateMachineImpl<*>) {
             // We have a request to do something: send, receive, or send-and-receive.
             if (request is FiberRequest.ExpectingResponse<*>) {
+                // We don't use the passed-in serializer here, because we need to use our own augmented Kryo.
+                val deserializer = Fiber.getFiberSerializer(false) as KryoSerializer
+                val kryo = createKryo(deserializer.kryo)
+                // add the map of tokens -> tokenizedServices to the kyro context
+                SerializeAsTokenSerializer.setContext(kryo, serializationContext)
+                val serialisedFiber = fiber.serialize(kryo)
                 // Prepare a listener on the network that runs in the background thread when we received a message.
                 checkpointAndSetupMessageHandler(psm, request, serialisedFiber)
             }
diff --git a/node/src/main/kotlin/com/r3corda/node/services/wallet/NodeWalletService.kt b/node/src/main/kotlin/com/r3corda/node/services/wallet/NodeWalletService.kt
index 6f73708568..ce0a5a656d 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/wallet/NodeWalletService.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/wallet/NodeWalletService.kt
@@ -8,6 +8,7 @@ import com.r3corda.core.crypto.Party
 import com.r3corda.core.crypto.SecureHash
 import com.r3corda.core.node.services.Wallet
 import com.r3corda.core.node.services.WalletService
+import com.r3corda.core.serialization.SingletonSerializeAsToken
 import com.r3corda.core.utilities.loggerFor
 import com.r3corda.core.utilities.trace
 import com.r3corda.node.services.api.ServiceHubInternal
@@ -21,7 +22,7 @@ import javax.annotation.concurrent.ThreadSafe
  * states relevant to us into a database and once such a wallet is implemented, this scaffolding can be removed.
  */
 @ThreadSafe
-class NodeWalletService(private val services: ServiceHubInternal) : WalletService {
+class NodeWalletService(private val services: ServiceHubInternal) : SingletonSerializeAsToken(), WalletService {
     private val log = loggerFor<NodeWalletService>()
 
     // Variables inside InnerState are protected with a lock by the ThreadBox and aren't in scope unless you're
diff --git a/node/src/test/kotlin/com/r3corda/node/services/MockServices.kt b/node/src/test/kotlin/com/r3corda/node/services/MockServices.kt
index bc24e12c91..b4331bf88a 100644
--- a/node/src/test/kotlin/com/r3corda/node/services/MockServices.kt
+++ b/node/src/test/kotlin/com/r3corda/node/services/MockServices.kt
@@ -5,6 +5,7 @@ import com.r3corda.core.messaging.MessagingService
 import com.r3corda.core.node.services.*
 import com.r3corda.core.node.services.testing.MockStorageService
 import com.r3corda.core.testing.MOCK_IDENTITY_SERVICE
+import com.r3corda.node.serialization.NodeClock
 import com.r3corda.node.services.api.Checkpoint
 import com.r3corda.node.services.api.CheckpointStorage
 import com.r3corda.node.services.api.MonitoringService
@@ -40,7 +41,7 @@ class MockServices(
         val storage: StorageService? = MockStorageService(),
         val mapCache: NetworkMapCache? = MockNetworkMapCache(),
         val mapService: NetworkMapService? = null,
-        val overrideClock: Clock? = Clock.systemUTC()
+        val overrideClock: Clock? = NodeClock()
 ) : ServiceHubInternal {
     override val walletService: WalletService = customWallet ?: NodeWalletService(this)
 
diff --git a/src/main/kotlin/com/r3corda/demos/DemoClock.kt b/src/main/kotlin/com/r3corda/demos/DemoClock.kt
index 3021a4e7aa..d113d31056 100644
--- a/src/main/kotlin/com/r3corda/demos/DemoClock.kt
+++ b/src/main/kotlin/com/r3corda/demos/DemoClock.kt
@@ -1,5 +1,8 @@
 package com.r3corda.demos
 
+import com.r3corda.core.serialization.SerializeAsToken
+import com.r3corda.core.serialization.SerializeAsTokenContext
+import com.r3corda.core.serialization.SingletonSerializationToken
 import com.r3corda.node.utilities.MutableClock
 import java.time.*
 import javax.annotation.concurrent.ThreadSafe
@@ -8,7 +11,11 @@ import javax.annotation.concurrent.ThreadSafe
  * A [Clock] that can have the date advanced for use in demos
  */
 @ThreadSafe
-class DemoClock(private var delegateClock: Clock = Clock.systemUTC()) : MutableClock() {
+class DemoClock(private var delegateClock: Clock = Clock.systemUTC()) : MutableClock(), SerializeAsToken {
+
+    private val token = SingletonSerializationToken(this)
+
+    override fun toToken(context: SerializeAsTokenContext) = SingletonSerializationToken.registerWithContext(token, this, context)
 
     @Synchronized fun updateDate(date: LocalDate): Boolean {
         val currentDate = LocalDate.now(this)
@@ -25,8 +32,9 @@ class DemoClock(private var delegateClock: Clock = Clock.systemUTC()) : MutableC
         return delegateClock.instant()
     }
 
-    @Synchronized override fun withZone(zone: ZoneId): Clock {
-        return DemoClock(delegateClock.withZone(zone))
+    // Do not use this. Instead seek to use ZonedDateTime methods.
+    override fun withZone(zone: ZoneId): Clock {
+        throw UnsupportedOperationException("Tokenized clock does not support withZone()")
     }
 
     @Synchronized override fun getZone(): ZoneId {