ENT-6947 Intern common types to reduce heap footprint (#7239)

ENT-6947: Implement interning for SecureHash, CordaX500Name, PublicKey, AsbtractParty and SignatureAttachmentConstraint, including automatic detection of internable types off companion objects in AMQP & Kyro deserialization.  In some cases, add new factory methods to companion objects, and make main code base use them.

Performance tested in performance cluster with no negative impact visible (so default concurrency setting seems okay).

Testing suggests 5-6x memory saving for tokens in TokensSDK in memory selector.  Should see approx. 1 million tokens per GB or better (1.5 million for the tokens we tested with).

.ci/api-current.txt

@@ -804,7 +804,16 @@ public final class net.corda.core.contracts.PartyAndReference extends java.lang.
 @CordaSerializable
 public final class net.corda.core.contracts.PrivacySalt extends net.corda.core.utilities.OpaqueBytes
   public <init>()
+  public <init>(int)
   public <init>(byte[])
+  @NotNull
+  public static final net.corda.core.contracts.PrivacySalt createFor(String)
+  public static final net.corda.core.contracts.PrivacySalt$Companion Companion
+##
+public static final class net.corda.core.contracts.PrivacySalt$Companion extends java.lang.Object
+  public <init>(kotlin.jvm.internal.DefaultConstructorMarker)
+  @NotNull
+  public final net.corda.core.contracts.PrivacySalt createFor(String)
 ##
 public final class net.corda.core.contracts.ReferencedStateAndRef extends java.lang.Object
   public <init>(net.corda.core.contracts.StateAndRef<? extends T>)
@@ -882,6 +891,14 @@ public final class net.corda.core.contracts.SignatureAttachmentConstraint extend
   public boolean isSatisfiedBy(net.corda.core.contracts.Attachment)
   @NotNull
   public String toString()
+  public static final net.corda.core.contracts.SignatureAttachmentConstraint$Companion Companion
+##
+public static final class net.corda.core.contracts.SignatureAttachmentConstraint$Companion extends java.lang.Object implements net.corda.core.internal.utilities.Internable
+  public <init>(kotlin.jvm.internal.DefaultConstructorMarker)
+  @NotNull
+  public final net.corda.core.contracts.SignatureAttachmentConstraint create(java.security.PublicKey)
+  @NotNull
+  public net.corda.core.internal.utilities.PrivateInterner<net.corda.core.contracts.SignatureAttachmentConstraint> getInterner()
 ##
 public final class net.corda.core.contracts.SourceAndAmount extends java.lang.Object
   public <init>(P, net.corda.core.contracts.Amount<T>, Object)
@@ -999,6 +1016,8 @@ public final class net.corda.core.contracts.Structures extends java.lang.Object
   @NotNull
   public static final net.corda.core.crypto.SecureHash hash(net.corda.core.contracts.ContractState)
   @NotNull
+  public static final net.corda.core.crypto.SecureHash hash(net.corda.core.contracts.ContractState, String)
+  @NotNull
   public static final net.corda.core.contracts.Amount<T> withoutIssuer(net.corda.core.contracts.Amount<net.corda.core.contracts.Issued<T>>)
   public static final int MAX_ISSUER_REF_SIZE = 512
 ##
@@ -1099,6 +1118,10 @@ public abstract class net.corda.core.contracts.TransactionVerificationException
   public final net.corda.core.crypto.SecureHash getTxId()
 ##
 @CordaSerializable
+public static final class net.corda.core.contracts.TransactionVerificationException$AttachmentTooBigException extends net.corda.core.contracts.TransactionVerificationException
+  public <init>(net.corda.core.crypto.SecureHash)
+##
+@CordaSerializable
 public static final class net.corda.core.contracts.TransactionVerificationException$BrokenTransactionException extends net.corda.core.contracts.TransactionVerificationException
   public <init>(net.corda.core.crypto.SecureHash, String)
 ##
@@ -1257,6 +1280,10 @@ public static final class net.corda.core.contracts.TransactionVerificationExcept
   public <init>(net.corda.core.crypto.SecureHash, String, Throwable)
 ##
 @CordaSerializable
+public static final class net.corda.core.contracts.TransactionVerificationException$UnsupportedHashTypeException extends net.corda.core.contracts.TransactionVerificationException
+  public <init>(net.corda.core.crypto.SecureHash)
+##
+@CordaSerializable
 public static final class net.corda.core.contracts.TransactionVerificationException$UntrustedAttachmentsException extends net.corda.core.CordaException
   public <init>(net.corda.core.crypto.SecureHash, java.util.List<? extends net.corda.core.crypto.SecureHash>)
   @NotNull
@@ -1861,6 +1888,53 @@ public interface net.corda.core.crypto.DigestAlgorithm
   public abstract byte[] nonceDigest(byte[])
 ##
 @CordaSerializable
+public final class net.corda.core.crypto.DigestService extends java.lang.Object
+  public <init>(String)
+  @NotNull
+  public final String component1()
+  @NotNull
+  public final net.corda.core.crypto.SecureHash componentHash(net.corda.core.crypto.SecureHash, net.corda.core.utilities.OpaqueBytes)
+  @NotNull
+  public final net.corda.core.crypto.SecureHash componentHash(net.corda.core.utilities.OpaqueBytes, net.corda.core.contracts.PrivacySalt, int, int)
+  @NotNull
+  public final net.corda.core.crypto.SecureHash computeNonce(net.corda.core.contracts.PrivacySalt, int, int)
+  @NotNull
+  public final net.corda.core.crypto.DigestService copy(String)
+  public boolean equals(Object)
+  @NotNull
+  public final net.corda.core.crypto.SecureHash getAllOnesHash()
+  public final int getDigestLength()
+  @NotNull
+  public final String getHashAlgorithm()
+  @NotNull
+  public final net.corda.core.crypto.SecureHash getZeroHash()
+  @NotNull
+  public final net.corda.core.crypto.SecureHash hash(String)
+  @NotNull
+  public final net.corda.core.crypto.SecureHash hash(byte[])
+  public int hashCode()
+  @NotNull
+  public final net.corda.core.crypto.SecureHash serializedHash(T)
+  @NotNull
+  public String toString()
+  public static final net.corda.core.crypto.DigestService$Companion Companion
+##
+public static final class net.corda.core.crypto.DigestService$Companion extends java.lang.Object
+  public <init>(kotlin.jvm.internal.DefaultConstructorMarker)
+  @NotNull
+  public final net.corda.core.crypto.DigestService getDefault()
+  @NotNull
+  public final net.corda.core.crypto.DigestService getSha2_256()
+  @NotNull
+  public final net.corda.core.crypto.DigestService getSha2_384()
+  @NotNull
+  public final net.corda.core.crypto.DigestService getSha2_512()
+##
+public final class net.corda.core.crypto.DigestServiceKt extends java.lang.Object
+  @NotNull
+  public static final net.corda.core.crypto.SecureHash randomHash(net.corda.core.crypto.DigestService)
+##
+@CordaSerializable
 public class net.corda.core.crypto.DigitalSignature extends net.corda.core.utilities.OpaqueBytes
   public <init>(byte[])
 ##
@@ -1888,6 +1962,8 @@ public static final class net.corda.core.crypto.MerkleTree$Companion extends jav
   public <init>(kotlin.jvm.internal.DefaultConstructorMarker)
   @NotNull
   public final net.corda.core.crypto.MerkleTree getMerkleTree(java.util.List<? extends net.corda.core.crypto.SecureHash>)
+  @NotNull
+  public final net.corda.core.crypto.MerkleTree getMerkleTree(java.util.List<? extends net.corda.core.crypto.SecureHash>, net.corda.core.crypto.DigestService)
 ##
 public static final class net.corda.core.crypto.MerkleTree$Leaf extends net.corda.core.crypto.MerkleTree
   public <init>(net.corda.core.crypto.SecureHash)
@@ -1997,14 +2073,23 @@ public static final class net.corda.core.crypto.PartialMerkleTree$PartialTree$Le
 ##
 @CordaSerializable
 public static final class net.corda.core.crypto.PartialMerkleTree$PartialTree$Node extends net.corda.core.crypto.PartialMerkleTree$PartialTree
+  @DeprecatedConstructorForDeserialization
   public <init>(net.corda.core.crypto.PartialMerkleTree$PartialTree, net.corda.core.crypto.PartialMerkleTree$PartialTree)
+  public <init>(net.corda.core.crypto.PartialMerkleTree$PartialTree, net.corda.core.crypto.PartialMerkleTree$PartialTree, String)
+  public <init>(net.corda.core.crypto.PartialMerkleTree$PartialTree, net.corda.core.crypto.PartialMerkleTree$PartialTree, String, int, kotlin.jvm.internal.DefaultConstructorMarker)
   @NotNull
   public final net.corda.core.crypto.PartialMerkleTree$PartialTree component1()
   @NotNull
   public final net.corda.core.crypto.PartialMerkleTree$PartialTree component2()
+  @Nullable
+  public final String component3()
   @NotNull
   public final net.corda.core.crypto.PartialMerkleTree$PartialTree$Node copy(net.corda.core.crypto.PartialMerkleTree$PartialTree, net.corda.core.crypto.PartialMerkleTree$PartialTree)
+  @NotNull
+  public final net.corda.core.crypto.PartialMerkleTree$PartialTree$Node copy(net.corda.core.crypto.PartialMerkleTree$PartialTree, net.corda.core.crypto.PartialMerkleTree$PartialTree, String)
   public boolean equals(Object)
+  @Nullable
+  public final String getHashAlgorithm()
   @NotNull
   public final net.corda.core.crypto.PartialMerkleTree$PartialTree getLeft()
   @NotNull
@@ -2017,36 +2102,86 @@ public static final class net.corda.core.crypto.PartialMerkleTree$PartialTree$No
 public abstract class net.corda.core.crypto.SecureHash extends net.corda.core.utilities.OpaqueBytes
   public <init>(byte[], kotlin.jvm.internal.DefaultConstructorMarker)
   @NotNull
+  public static final net.corda.core.crypto.SecureHash allOnesHashFor(String)
+  @NotNull
+  public static final net.corda.core.crypto.SecureHash componentHashAs(String, byte[])
+  @NotNull
+  public final net.corda.core.crypto.SecureHash concatenate(net.corda.core.crypto.SecureHash)
+  @NotNull
+  public final net.corda.core.crypto.SecureHash concatenateAs(String, net.corda.core.crypto.SecureHash)
+  @NotNull
+  public static final net.corda.core.crypto.SecureHash create(String)
+  @NotNull
+  public static final net.corda.core.crypto.SecureHash$SHA256 createSHA256(byte[])
+  @NotNull
+  protected net.corda.core.crypto.SecureHash generate(byte[])
+  @NotNull
+  public static final net.corda.core.crypto.SecureHash hashAs(String, byte[])
+  @NotNull
   public final net.corda.core.crypto.SecureHash$SHA256 hashConcat(net.corda.core.crypto.SecureHash)
   @NotNull
+  public static final net.corda.core.crypto.SecureHash nonceHashAs(String, byte[])
+  @NotNull
   public static final net.corda.core.crypto.SecureHash$SHA256 parse(String)
   @NotNull
   public final String prefixChars(int)
   @NotNull
+  public static final net.corda.core.crypto.SecureHash random(String)
+  @NotNull
   public static final net.corda.core.crypto.SecureHash$SHA256 randomSHA256()
   @NotNull
+  public final net.corda.core.crypto.SecureHash reHash()
+  @NotNull
   public static final net.corda.core.crypto.SecureHash$SHA256 sha256(String)
   @NotNull
   public static final net.corda.core.crypto.SecureHash$SHA256 sha256(byte[])
   @NotNull
   public static final net.corda.core.crypto.SecureHash$SHA256 sha256Twice(byte[])
   @NotNull
+  public final String toHexString()
+  @NotNull
   public String toString()
+  @NotNull
+  public static final net.corda.core.crypto.SecureHash zeroHashFor(String)
   public static final net.corda.core.crypto.SecureHash$Companion Companion
+  public static final char DELIMITER = ':'
+  @NotNull
+  public static final String SHA2_256 = "SHA-256"
+  @NotNull
+  public static final String SHA2_384 = "SHA-384"
+  @NotNull
+  public static final String SHA2_512 = "SHA-512"
   @NotNull
   public static final net.corda.core.crypto.SecureHash$SHA256 allOnesHash
   @NotNull
   public static final net.corda.core.crypto.SecureHash$SHA256 zeroHash
 ##
-public static final class net.corda.core.crypto.SecureHash$Companion extends java.lang.Object
+public static final class net.corda.core.crypto.SecureHash$Companion extends java.lang.Object implements net.corda.core.internal.utilities.Internable
   public <init>(kotlin.jvm.internal.DefaultConstructorMarker)
   @NotNull
+  public final net.corda.core.crypto.SecureHash allOnesHashFor(String)
+  @NotNull
+  public final net.corda.core.crypto.SecureHash componentHashAs(String, byte[])
+  @NotNull
+  public final net.corda.core.crypto.SecureHash create(String)
+  @NotNull
+  public final net.corda.core.crypto.SecureHash$SHA256 createSHA256(byte[])
+  public final int digestLengthFor(String)
+  @NotNull
   public final net.corda.core.crypto.SecureHash$SHA256 getAllOnesHash()
   @NotNull
+  public net.corda.core.internal.utilities.PrivateInterner<net.corda.core.crypto.SecureHash> getInterner()
+  @NotNull
   public final net.corda.core.crypto.SecureHash$SHA256 getZeroHash()
   @NotNull
+  public final net.corda.core.crypto.SecureHash hashAs(String, byte[])
+  @NotNull
+  public final net.corda.core.crypto.SecureHash nonceHashAs(String, byte[])
+  @NotNull
   public final net.corda.core.crypto.SecureHash$SHA256 parse(String)
   @NotNull
+  public final net.corda.core.crypto.SecureHash random(String)
+  @NotNull
   public final net.corda.core.crypto.SecureHash$SHA256 randomSHA256()
   @NotNull
   public final net.corda.core.crypto.SecureHash$SHA256 sha256(String)
@@ -2054,14 +2189,39 @@ public static final class net.corda.core.crypto.SecureHash$Companion extends jav
   public final net.corda.core.crypto.SecureHash$SHA256 sha256(byte[])
   @NotNull
   public final net.corda.core.crypto.SecureHash$SHA256 sha256Twice(byte[])
+  @NotNull
+  public final net.corda.core.crypto.SecureHash zeroHashFor(String)
+##
+@CordaSerializable
+public static final class net.corda.core.crypto.SecureHash$HASH extends net.corda.core.crypto.SecureHash
+  public <init>(String, byte[])
+  public boolean equals(Object)
+  @NotNull
+  protected net.corda.core.crypto.SecureHash generate(byte[])
+  @NotNull
+  public final String getAlgorithm()
+  public int hashCode()
+  @NotNull
+  public String toString()
 ##
 @CordaSerializable
 public static final class net.corda.core.crypto.SecureHash$SHA256 extends net.corda.core.crypto.SecureHash
   public <init>(byte[])
   public boolean equals(Object)
+  @NotNull
+  protected net.corda.core.crypto.SecureHash generate(byte[])
   public int hashCode()
+  @NotNull
+  public String toString()
 ##
 public final class net.corda.core.crypto.SecureHashKt extends java.lang.Object
+  @NotNull
+  public static final String getAlgorithm(net.corda.core.crypto.SecureHash)
+  @NotNull
+  public static final net.corda.core.crypto.SecureHash hashAs(net.corda.core.utilities.OpaqueBytes, String)
+  @NotNull
+  public static final net.corda.core.crypto.SecureHash hashAs(byte[], String)
+  public static final boolean isZero(net.corda.core.utilities.OpaqueBytes)
   @NotNull
   public static final net.corda.core.crypto.SecureHash$SHA256 sha256(net.corda.core.utilities.OpaqueBytes)
   @NotNull
@@ -3157,6 +3317,24 @@ public static final class net.corda.core.flows.WithReferencedStatesFlow$Companio
 public static final class net.corda.core.flows.WithReferencedStatesFlow$Companion$SUCCESS extends net.corda.core.utilities.ProgressTracker$Step
   public static final net.corda.core.flows.WithReferencedStatesFlow$Companion$SUCCESS INSTANCE
 ##
+@CordaSerializable
+public final class net.corda.core.flows.WrappedFlowExternalAsyncOperation extends java.lang.Object implements net.corda.core.internal.FlowAsyncOperation
+  public <init>(net.corda.core.flows.FlowExternalAsyncOperation<R>)
+  @NotNull
+  public net.corda.core.concurrent.CordaFuture<R> execute(String)
+  @NotNull
+  public final net.corda.core.flows.FlowExternalAsyncOperation<R> getOperation()
+##
+@CordaSerializable
+public final class net.corda.core.flows.WrappedFlowExternalOperation extends java.lang.Object implements net.corda.core.internal.FlowAsyncOperation
+  public <init>(net.corda.core.internal.ServiceHubCoreInternal, net.corda.core.flows.FlowExternalOperation<R>)
+  @NotNull
+  public net.corda.core.concurrent.CordaFuture<R> execute(String)
+  @NotNull
+  public final net.corda.core.flows.FlowExternalOperation<R> getOperation()
+  @NotNull
+  public final net.corda.core.internal.ServiceHubCoreInternal getServiceHub()
+##
 @DoNotImplement
 @CordaSerializable
 public abstract class net.corda.core.identity.AbstractParty extends java.lang.Object implements net.corda.core.flows.Destination
@@ -3171,6 +3349,7 @@ public abstract class net.corda.core.identity.AbstractParty extends java.lang.Ob
   public abstract net.corda.core.contracts.PartyAndReference ref(net.corda.core.utilities.OpaqueBytes)
   @NotNull
   public final net.corda.core.contracts.PartyAndReference ref(byte...)
+  public static final net.corda.core.identity.AbstractParty$Companion Companion
 ##
 @DoNotImplement
 @CordaSerializable
@@ -3182,6 +3361,12 @@ public final class net.corda.core.identity.AnonymousParty extends net.corda.core
   public net.corda.core.contracts.PartyAndReference ref(net.corda.core.utilities.OpaqueBytes)
   @NotNull
   public String toString()
+  public static final net.corda.core.identity.AnonymousParty$Companion Companion
+##
+public static final class net.corda.core.identity.AnonymousParty$Companion extends java.lang.Object
+  public <init>(kotlin.jvm.internal.DefaultConstructorMarker)
+  @NotNull
+  public final net.corda.core.identity.AnonymousParty create(java.security.PublicKey)
 ##
 @CordaSerializable
 public final class net.corda.core.identity.CordaX500Name extends java.lang.Object
@@ -3232,11 +3417,13 @@ public final class net.corda.core.identity.CordaX500Name extends java.lang.Objec
   public static final int MAX_LENGTH_ORGANISATION_UNIT = 64
   public static final int MAX_LENGTH_STATE = 64
 ##
-public static final class net.corda.core.identity.CordaX500Name$Companion extends java.lang.Object
+public static final class net.corda.core.identity.CordaX500Name$Companion extends java.lang.Object implements net.corda.core.internal.utilities.Internable
   public <init>(kotlin.jvm.internal.DefaultConstructorMarker)
   @NotNull
   public final net.corda.core.identity.CordaX500Name build(javax.security.auth.x500.X500Principal)
   @NotNull
+  public net.corda.core.internal.utilities.PrivateInterner<net.corda.core.identity.CordaX500Name> getInterner()
+  @NotNull
   public final net.corda.core.identity.CordaX500Name parse(String)
 ##
 public final class net.corda.core.identity.IdentityUtils extends java.lang.Object
@@ -3262,6 +3449,8 @@ public final class net.corda.core.identity.Party extends net.corda.core.identity
   @NotNull
   public final net.corda.core.identity.AnonymousParty anonymise()
   @NotNull
+  public final String description()
+  @NotNull
   public final net.corda.core.identity.CordaX500Name getName()
   @NotNull
   public net.corda.core.identity.CordaX500Name nameOrNull()
@@ -3269,6 +3458,14 @@ public final class net.corda.core.identity.Party extends net.corda.core.identity
   public net.corda.core.contracts.PartyAndReference ref(net.corda.core.utilities.OpaqueBytes)
   @NotNull
   public String toString()
+  public static final net.corda.core.identity.Party$Companion Companion
+##
+public static final class net.corda.core.identity.Party$Companion extends java.lang.Object
+  public <init>(kotlin.jvm.internal.DefaultConstructorMarker)
+  @NotNull
+  public final net.corda.core.identity.Party create(java.security.cert.X509Certificate)
+  @NotNull
+  public final net.corda.core.identity.Party create(net.corda.core.identity.CordaX500Name, java.security.PublicKey)
 ##
 @CordaSerializable
 public final class net.corda.core.identity.PartyAndCertificate extends java.lang.Object
@@ -3293,6 +3490,8 @@ public final class net.corda.core.identity.PartyAndCertificate extends java.lang
   public String toString()
   @NotNull
   public final java.security.cert.PKIXCertPathValidatorResult verify(java.security.cert.TrustAnchor)
+  @NotNull
+  public final java.security.cert.PKIXCertPathValidatorResult verify(java.util.Set<? extends java.security.cert.TrustAnchor>)
 ##
 @CordaSerializable
 public interface net.corda.core.messaging.AllPossibleRecipients extends net.corda.core.messaging.MessageRecipients
@@ -3330,6 +3529,8 @@ public interface net.corda.core.messaging.CordaRPCOps extends net.corda.core.mes
   @NotNull
   public abstract java.util.Map<String, Boolean> finishedFlowsWithClientIds()
   @NotNull
+  public abstract java.util.Map<String, Boolean> finishedFlowsWithClientIdsAsAdmin()
+  @NotNull
   public abstract net.corda.core.node.NetworkParameters getNetworkParameters()
   @NotNull
   public abstract Iterable<String> getVaultTransactionNotes(net.corda.core.crypto.SecureHash)
@@ -3374,6 +3575,7 @@ public interface net.corda.core.messaging.CordaRPCOps extends net.corda.core.mes
   @NotNull
   public abstract java.util.List<String> registeredFlows()
   public abstract boolean removeClientId(String)
+  public abstract boolean removeClientIdAsAdmin(String)
   public abstract void setFlowsDrainingModeEnabled(boolean)
   public abstract void shutdown()
   @RPCReturnsObservables
@@ -3691,6 +3893,11 @@ public static final class net.corda.core.messaging.StateMachineUpdate$Removed ex
   public String toString()
 ##
 @DoNotImplement
+public interface net.corda.core.messaging.flows.FlowManagerRPCOps extends net.corda.core.messaging.RPCOps
+  public abstract void debugCheckpoints()
+  public abstract void dumpCheckpoints()
+##
+@DoNotImplement
 public interface net.corda.core.node.AppServiceHub extends net.corda.core.node.ServiceHub
   @NotNull
   public abstract net.corda.core.node.services.vault.CordaTransactionSupport getDatabase()
@@ -3756,8 +3963,12 @@ public final class net.corda.core.node.NetworkParameters extends java.lang.Objec
   public final java.util.Map<String, java.util.List<net.corda.core.crypto.SecureHash>> getWhitelistedContractImplementations()
   public int hashCode()
   @NotNull
+  public final net.corda.core.node.NetworkParameters toImmutable()
+  @NotNull
   public String toString()
 ##
+public final class net.corda.core.node.NetworkParametersKt extends java.lang.Object
+##
 @CordaSerializable
 public final class net.corda.core.node.NodeDiagnosticInfo extends java.lang.Object
   public <init>(String, String, int, String, java.util.List<net.corda.core.cordapp.CordappInfo>)
@@ -5990,6 +6201,11 @@ public final class net.corda.core.serialization.SerializationAPIKt extends java.
   public static final net.corda.core.serialization.SerializedBytes<T> serialize(T, net.corda.core.serialization.SerializationFactory, net.corda.core.serialization.SerializationContext)
   @NotNull
   public static final net.corda.core.serialization.SerializationContext withWhitelist(net.corda.core.serialization.SerializationContext, java.util.List<? extends Class<?>>)
+  public static final int AMQP_ENVELOPE_CACHE_INITIAL_CAPACITY = 256
+  @NotNull
+  public static final String AMQP_ENVELOPE_CACHE_PROPERTY = "AMQP_ENVELOPE_CACHE"
+  @NotNull
+  public static final String DESERIALIZATION_CACHE_PROPERTY = "DESERIALIZATION_CACHE"
 ##
 @DoNotImplement
 public interface net.corda.core.serialization.SerializationContext
@@ -6030,6 +6246,8 @@ public interface net.corda.core.serialization.SerializationContext
   @NotNull
   public abstract net.corda.core.serialization.SerializationContext withPreventDataLoss()
   @NotNull
+  public abstract net.corda.core.serialization.SerializationContext withProperties(java.util.Map<Object, ?>)
+  @NotNull
   public abstract net.corda.core.serialization.SerializationContext withProperty(Object, Object)
   @NotNull
   public abstract net.corda.core.serialization.SerializationContext withWhitelisted(Class<?>)
@@ -6090,6 +6308,8 @@ public interface net.corda.core.serialization.SerializationSchemeContext
   @NotNull
   public abstract ClassLoader getDeserializationClassLoader()
   @NotNull
+  public abstract java.util.Map<Object, Object> getProperties()
+  @NotNull
   public abstract net.corda.core.serialization.ClassWhitelist getWhitelist()
 ##
 public interface net.corda.core.serialization.SerializationToken
@@ -6206,15 +6426,23 @@ public final class net.corda.core.transactions.ComponentVisibilityException exte
 @DoNotImplement
 @CordaSerializable
 public final class net.corda.core.transactions.ContractUpgradeFilteredTransaction extends net.corda.core.transactions.CoreTransaction
+  @DeprecatedConstructorForDeserialization
   public <init>(java.util.Map<Integer, net.corda.core.transactions.ContractUpgradeFilteredTransaction$FilteredComponent>, java.util.Map<Integer, ? extends net.corda.core.crypto.SecureHash>)
+  public <init>(java.util.Map<Integer, net.corda.core.transactions.ContractUpgradeFilteredTransaction$FilteredComponent>, java.util.Map<Integer, ? extends net.corda.core.crypto.SecureHash>, net.corda.core.crypto.DigestService)
   @NotNull
   public final java.util.Map<Integer, net.corda.core.transactions.ContractUpgradeFilteredTransaction$FilteredComponent> component1()
   @NotNull
   public final java.util.Map<Integer, net.corda.core.crypto.SecureHash> component2()
   @NotNull
+  public final net.corda.core.crypto.DigestService component3()
+  @NotNull
   public final net.corda.core.transactions.ContractUpgradeFilteredTransaction copy(java.util.Map<Integer, net.corda.core.transactions.ContractUpgradeFilteredTransaction$FilteredComponent>, java.util.Map<Integer, ? extends net.corda.core.crypto.SecureHash>)
+  @NotNull
+  public final net.corda.core.transactions.ContractUpgradeFilteredTransaction copy(java.util.Map<Integer, net.corda.core.transactions.ContractUpgradeFilteredTransaction$FilteredComponent>, java.util.Map<Integer, ? extends net.corda.core.crypto.SecureHash>, net.corda.core.crypto.DigestService)
   public boolean equals(Object)
   @NotNull
+  public final net.corda.core.crypto.DigestService getDigestService()
+  @NotNull
   public final java.util.Map<Integer, net.corda.core.crypto.SecureHash> getHiddenComponents()
   @NotNull
   public net.corda.core.crypto.SecureHash getId()
@@ -6304,8 +6532,11 @@ public static final class net.corda.core.transactions.ContractUpgradeLedgerTrans
 @DoNotImplement
 @CordaSerializable
 public final class net.corda.core.transactions.ContractUpgradeWireTransaction extends net.corda.core.transactions.CoreTransaction
+  @DeprecatedConstructorForDeserialization
   public <init>(java.util.List<? extends net.corda.core.utilities.OpaqueBytes>, net.corda.core.contracts.PrivacySalt)
+  @DeprecatedConstructorForDeserialization
   public <init>(java.util.List, net.corda.core.contracts.PrivacySalt, int, kotlin.jvm.internal.DefaultConstructorMarker)
+  public <init>(java.util.List<? extends net.corda.core.utilities.OpaqueBytes>, net.corda.core.contracts.PrivacySalt, net.corda.core.crypto.DigestService)
   @NotNull
   public final net.corda.core.transactions.ContractUpgradeFilteredTransaction buildFilteredTransaction()
   @NotNull
@@ -6313,9 +6544,15 @@ public final class net.corda.core.transactions.ContractUpgradeWireTransaction ex
   @NotNull
   public final net.corda.core.contracts.PrivacySalt component2()
   @NotNull
+  public final net.corda.core.crypto.DigestService component3()
+  @NotNull
   public final net.corda.core.transactions.ContractUpgradeWireTransaction copy(java.util.List<? extends net.corda.core.utilities.OpaqueBytes>, net.corda.core.contracts.PrivacySalt)
+  @NotNull
+  public final net.corda.core.transactions.ContractUpgradeWireTransaction copy(java.util.List<? extends net.corda.core.utilities.OpaqueBytes>, net.corda.core.contracts.PrivacySalt, net.corda.core.crypto.DigestService)
   public boolean equals(Object)
   @NotNull
+  public final net.corda.core.crypto.DigestService getDigestService()
+  @NotNull
   public net.corda.core.crypto.SecureHash getId()
   @NotNull
   public java.util.List<net.corda.core.contracts.StateRef> getInputs()
@@ -6389,7 +6626,9 @@ public final class net.corda.core.transactions.FilteredComponentGroup extends ne
 @DoNotImplement
 @CordaSerializable
 public final class net.corda.core.transactions.FilteredTransaction extends net.corda.core.transactions.TraversableTransaction
+  @DeprecatedConstructorForDeserialization
   public <init>(net.corda.core.crypto.SecureHash, java.util.List<net.corda.core.transactions.FilteredComponentGroup>, java.util.List<? extends net.corda.core.crypto.SecureHash>)
+  public <init>(net.corda.core.crypto.SecureHash, java.util.List<net.corda.core.transactions.FilteredComponentGroup>, java.util.List<? extends net.corda.core.crypto.SecureHash>, net.corda.core.crypto.DigestService)
   @NotNull
   public static final net.corda.core.transactions.FilteredTransaction buildFilteredTransaction(net.corda.core.transactions.WireTransaction, java.util.function.Predicate<Object>)
   public final void checkAllComponentsVisible(net.corda.core.contracts.ComponentGroupEnum)
@@ -6433,6 +6672,7 @@ public abstract class net.corda.core.transactions.FullTransaction extends net.co
 public final class net.corda.core.transactions.LedgerTransaction extends net.corda.core.transactions.FullTransaction
   public <init>(java.util.List<? extends net.corda.core.contracts.StateAndRef<? extends net.corda.core.contracts.ContractState>>, java.util.List<? extends net.corda.core.contracts.TransactionState<? extends net.corda.core.contracts.ContractState>>, java.util.List<? extends net.corda.core.contracts.CommandWithParties<? extends net.corda.core.contracts.CommandData>>, java.util.List<? extends net.corda.core.contracts.Attachment>, net.corda.core.crypto.SecureHash, net.corda.core.identity.Party, net.corda.core.contracts.TimeWindow, net.corda.core.contracts.PrivacySalt)
   public <init>(java.util.List<? extends net.corda.core.contracts.StateAndRef<? extends net.corda.core.contracts.ContractState>>, java.util.List<? extends net.corda.core.contracts.TransactionState<? extends net.corda.core.contracts.ContractState>>, java.util.List<? extends net.corda.core.contracts.CommandWithParties<? extends net.corda.core.contracts.CommandData>>, java.util.List<? extends net.corda.core.contracts.Attachment>, net.corda.core.crypto.SecureHash, net.corda.core.identity.Party, net.corda.core.contracts.TimeWindow, net.corda.core.contracts.PrivacySalt, net.corda.core.node.NetworkParameters)
+  public <init>(java.util.List, java.util.List, java.util.List, java.util.List, net.corda.core.crypto.SecureHash, net.corda.core.identity.Party, net.corda.core.contracts.TimeWindow, net.corda.core.contracts.PrivacySalt, net.corda.core.node.NetworkParameters, java.util.List, java.util.List, java.util.List, java.util.List, kotlin.jvm.functions.Function1, kotlin.jvm.functions.Function2, net.corda.core.serialization.internal.AttachmentsClassLoaderCache, net.corda.core.crypto.DigestService, kotlin.jvm.internal.DefaultConstructorMarker)
   @NotNull
   public final java.util.List<net.corda.core.contracts.Command<T>> commandsOfType(Class<T>)
   @NotNull
@@ -6491,6 +6731,8 @@ public final class net.corda.core.transactions.LedgerTransaction extends net.cor
   @NotNull
   public final java.util.List<net.corda.core.contracts.CommandWithParties<net.corda.core.contracts.CommandData>> getCommands()
   @NotNull
+  public final net.corda.core.crypto.DigestService getDigestService()
+  @NotNull
   public net.corda.core.crypto.SecureHash getId()
   @NotNull
   public final net.corda.core.contracts.ContractState getInput(int)
@@ -6629,14 +6871,22 @@ public static final class net.corda.core.transactions.NotaryChangeLedgerTransact
 @DoNotImplement
 @CordaSerializable
 public final class net.corda.core.transactions.NotaryChangeWireTransaction extends net.corda.core.transactions.CoreTransaction
+  @DeprecatedConstructorForDeserialization
   public <init>(java.util.List<? extends net.corda.core.utilities.OpaqueBytes>)
+  public <init>(java.util.List<? extends net.corda.core.utilities.OpaqueBytes>, net.corda.core.crypto.DigestService)
   public <init>(java.util.List<net.corda.core.contracts.StateRef>, net.corda.core.identity.Party, net.corda.core.identity.Party)
   @NotNull
   public final java.util.List<net.corda.core.utilities.OpaqueBytes> component1()
   @NotNull
+  public final net.corda.core.crypto.DigestService component2()
+  @NotNull
   public final net.corda.core.transactions.NotaryChangeWireTransaction copy(java.util.List<? extends net.corda.core.utilities.OpaqueBytes>)
+  @NotNull
+  public final net.corda.core.transactions.NotaryChangeWireTransaction copy(java.util.List<? extends net.corda.core.utilities.OpaqueBytes>, net.corda.core.crypto.DigestService)
   public boolean equals(Object)
   @NotNull
+  public final net.corda.core.crypto.DigestService getDigestService()
+  @NotNull
   public net.corda.core.crypto.SecureHash getId()
   @NotNull
   public java.util.List<net.corda.core.contracts.StateRef> getInputs()
@@ -6851,6 +7101,10 @@ public class net.corda.core.transactions.TransactionBuilder extends java.lang.Ob
   public final net.corda.core.transactions.SignedTransaction toSignedTransaction(net.corda.core.node.services.KeyManagementService, java.security.PublicKey, net.corda.core.crypto.SignatureMetadata, net.corda.core.node.ServicesForResolution)
   @NotNull
   public final net.corda.core.transactions.WireTransaction toWireTransaction(net.corda.core.node.ServicesForResolution)
+  @NotNull
+  public final net.corda.core.transactions.WireTransaction toWireTransaction(net.corda.core.node.ServicesForResolution, int)
+  @NotNull
+  public final net.corda.core.transactions.WireTransaction toWireTransaction(net.corda.core.node.ServicesForResolution, int, java.util.Map<Object, ?>)
   public final void verify(net.corda.core.node.ServiceHub)
   @NotNull
   public final net.corda.core.transactions.TransactionBuilder withItems(Object...)
@@ -6874,7 +7128,9 @@ public interface net.corda.core.transactions.TransactionWithSignatures extends n
 @DoNotImplement
 @CordaSerializable
 public abstract class net.corda.core.transactions.TraversableTransaction extends net.corda.core.transactions.CoreTransaction
+  @DeprecatedConstructorForDeserialization
   public <init>(java.util.List<? extends net.corda.core.transactions.ComponentGroup>)
+  public <init>(java.util.List<? extends net.corda.core.transactions.ComponentGroup>, net.corda.core.crypto.DigestService)
   @NotNull
   public final java.util.List<net.corda.core.crypto.SecureHash> getAttachments()
   @NotNull
@@ -6884,6 +7140,8 @@ public abstract class net.corda.core.transactions.TraversableTransaction extends
   @NotNull
   public java.util.List<net.corda.core.transactions.ComponentGroup> getComponentGroups()
   @NotNull
+  public final net.corda.core.crypto.DigestService getDigestService()
+  @NotNull
   public java.util.List<net.corda.core.contracts.StateRef> getInputs()
   @Nullable
   public net.corda.core.crypto.SecureHash getNetworkParametersHash()
@@ -6903,8 +7161,11 @@ public final class net.corda.core.transactions.WireTransaction extends net.corda
   public <init>(java.util.List<net.corda.core.contracts.StateRef>, java.util.List<? extends net.corda.core.crypto.SecureHash>, java.util.List<? extends net.corda.core.contracts.TransactionState<? extends net.corda.core.contracts.ContractState>>, java.util.List<? extends net.corda.core.contracts.Command<?>>, net.corda.core.identity.Party, net.corda.core.contracts.TimeWindow)
   public <init>(java.util.List<net.corda.core.contracts.StateRef>, java.util.List<? extends net.corda.core.crypto.SecureHash>, java.util.List<? extends net.corda.core.contracts.TransactionState<? extends net.corda.core.contracts.ContractState>>, java.util.List<? extends net.corda.core.contracts.Command<?>>, net.corda.core.identity.Party, net.corda.core.contracts.TimeWindow, net.corda.core.contracts.PrivacySalt)
   public <init>(java.util.List, java.util.List, java.util.List, java.util.List, net.corda.core.identity.Party, net.corda.core.contracts.TimeWindow, net.corda.core.contracts.PrivacySalt, int, kotlin.jvm.internal.DefaultConstructorMarker)
+  @DeprecatedConstructorForDeserialization
   public <init>(java.util.List<? extends net.corda.core.transactions.ComponentGroup>, net.corda.core.contracts.PrivacySalt)
+  @DeprecatedConstructorForDeserialization
   public <init>(java.util.List, net.corda.core.contracts.PrivacySalt, int, kotlin.jvm.internal.DefaultConstructorMarker)
+  public <init>(java.util.List<? extends net.corda.core.transactions.ComponentGroup>, net.corda.core.contracts.PrivacySalt, net.corda.core.crypto.DigestService)
   @NotNull
   public final net.corda.core.transactions.FilteredTransaction buildFilteredTransaction(java.util.function.Predicate<Object>)
   public final void checkSignature(net.corda.core.crypto.TransactionSignature)
@@ -7290,6 +7551,12 @@ public final class net.corda.core.utilities.SgxSupport extends java.lang.Object
   public static final boolean isInsideEnclave()
   public static final net.corda.core.utilities.SgxSupport INSTANCE
 ##
+public final class net.corda.core.utilities.ThreadDumpUtilsKt extends java.lang.Object
+  @NotNull
+  public static final String asString(management.ThreadInfo, int)
+  @NotNull
+  public static final String threadDumpAsString()
+##
 @CordaSerializable
 public abstract class net.corda.core.utilities.Try extends java.lang.Object
   public <init>(kotlin.jvm.internal.DefaultConstructorMarker)
@@ -7709,6 +7976,8 @@ public final class net.corda.testing.core.TestConstants extends java.lang.Object
   @NotNull
   public static final net.corda.core.identity.CordaX500Name CHARLIE_NAME
   @NotNull
+  public static final net.corda.core.identity.CordaX500Name DAVE_NAME
+  @NotNull
   public static final net.corda.core.identity.CordaX500Name DUMMY_BANK_A_NAME
   @NotNull
   public static final net.corda.core.identity.CordaX500Name DUMMY_BANK_B_NAME
@@ -7752,6 +8021,7 @@ public static final class net.corda.testing.core.TestIdentity$Companion extends
   public final net.corda.testing.core.TestIdentity fresh(String, net.corda.core.crypto.SignatureScheme)
 ##
 public final class net.corda.testing.core.TestUtils extends java.lang.Object
+  public static final T executeTest(java.time.Duration, kotlin.jvm.functions.Function0<kotlin.Unit>, java.time.Duration, kotlin.jvm.functions.Function0<? extends T>)
   @NotNull
   public static final net.corda.core.utilities.NetworkHostAndPort freeLocalHostAndPort()
   public static final int freePort()
@@ -8085,6 +8355,8 @@ public final class net.corda.testing.driver.DriverParameters extends java.lang.O
   public <init>(boolean, java.nio.file.Path, net.corda.testing.driver.PortAllocation, net.corda.testing.driver.PortAllocation, java.util.Map, boolean, boolean, boolean, java.util.List, java.util.List, net.corda.testing.driver.JmxPolicy, net.corda.core.node.NetworkParameters, java.util.Map, boolean, java.util.Collection, int, kotlin.jvm.internal.DefaultConstructorMarker)
   public <init>(boolean, java.nio.file.Path, net.corda.testing.driver.PortAllocation, net.corda.testing.driver.PortAllocation, java.util.Map<String, String>, boolean, boolean, boolean, java.util.List<net.corda.testing.node.NotarySpec>, java.util.List<String>, net.corda.testing.driver.JmxPolicy, net.corda.core.node.NetworkParameters, java.util.Map<String, ?>, boolean, java.util.Collection<? extends net.corda.testing.node.TestCordapp>, java.nio.file.Path, java.util.List<? extends java.nio.file.Path>, java.util.Map<String, String>, boolean)
   public <init>(boolean, java.nio.file.Path, net.corda.testing.driver.PortAllocation, net.corda.testing.driver.PortAllocation, java.util.Map, boolean, boolean, boolean, java.util.List, java.util.List, net.corda.testing.driver.JmxPolicy, net.corda.core.node.NetworkParameters, java.util.Map, boolean, java.util.Collection, java.nio.file.Path, java.util.List, java.util.Map, boolean, int, kotlin.jvm.internal.DefaultConstructorMarker)
+  public <init>(boolean, java.nio.file.Path, net.corda.testing.driver.PortAllocation, net.corda.testing.driver.PortAllocation, java.util.Map<String, String>, boolean, boolean, boolean, java.util.List<net.corda.testing.node.NotarySpec>, java.util.List<String>, net.corda.testing.driver.JmxPolicy, net.corda.core.node.NetworkParameters, java.util.Map<String, ?>, boolean, java.util.Collection<? extends net.corda.testing.node.TestCordapp>, java.nio.file.Path, java.util.List<? extends java.nio.file.Path>, java.util.Map<String, String>, boolean, boolean)
+  public <init>(boolean, java.nio.file.Path, net.corda.testing.driver.PortAllocation, net.corda.testing.driver.PortAllocation, java.util.Map, boolean, boolean, boolean, java.util.List, java.util.List, net.corda.testing.driver.JmxPolicy, net.corda.core.node.NetworkParameters, java.util.Map, boolean, java.util.Collection, java.nio.file.Path, java.util.List, java.util.Map, boolean, boolean, int, kotlin.jvm.internal.DefaultConstructorMarker)
   public <init>(boolean, java.nio.file.Path, net.corda.testing.driver.PortAllocation, net.corda.testing.driver.PortAllocation, java.util.Map<String, String>, boolean, boolean, boolean, java.util.List<net.corda.testing.node.NotarySpec>, java.util.List<String>, net.corda.testing.driver.JmxPolicy, net.corda.core.node.NetworkParameters, boolean)
   public final boolean component1()
   @NotNull
@@ -8107,6 +8379,7 @@ public final class net.corda.testing.driver.DriverParameters extends java.lang.O
   public final boolean component19()
   @NotNull
   public final java.nio.file.Path component2()
+  public final boolean component20()
   @NotNull
   public final net.corda.testing.driver.PortAllocation component3()
   @NotNull
@@ -8125,6 +8398,8 @@ public final class net.corda.testing.driver.DriverParameters extends java.lang.O
   @NotNull
   public final net.corda.testing.driver.DriverParameters copy(boolean, java.nio.file.Path, net.corda.testing.driver.PortAllocation, net.corda.testing.driver.PortAllocation, java.util.Map<String, String>, boolean, boolean, boolean, java.util.List<net.corda.testing.node.NotarySpec>, java.util.List<String>, net.corda.testing.driver.JmxPolicy, net.corda.core.node.NetworkParameters, java.util.Map<String, ?>, boolean, java.util.Collection<? extends net.corda.testing.node.TestCordapp>, java.nio.file.Path, java.util.List<? extends java.nio.file.Path>, java.util.Map<String, String>, boolean)
   @NotNull
+  public final net.corda.testing.driver.DriverParameters copy(boolean, java.nio.file.Path, net.corda.testing.driver.PortAllocation, net.corda.testing.driver.PortAllocation, java.util.Map<String, String>, boolean, boolean, boolean, java.util.List<net.corda.testing.node.NotarySpec>, java.util.List<String>, net.corda.testing.driver.JmxPolicy, net.corda.core.node.NetworkParameters, java.util.Map<String, ?>, boolean, java.util.Collection<? extends net.corda.testing.node.TestCordapp>, java.nio.file.Path, java.util.List<? extends java.nio.file.Path>, java.util.Map<String, String>, boolean, boolean)
+  @NotNull
   public final net.corda.testing.driver.DriverParameters copy(boolean, java.nio.file.Path, net.corda.testing.driver.PortAllocation, net.corda.testing.driver.PortAllocation, java.util.Map<String, String>, boolean, boolean, boolean, java.util.List<net.corda.testing.node.NotarySpec>, java.util.List<String>, net.corda.testing.driver.JmxPolicy, net.corda.core.node.NetworkParameters, java.util.Set<? extends net.corda.testing.node.TestCordapp>)
   public boolean equals(Object)
   public final boolean getAllowHibernateToManageAppSchema()
@@ -8153,6 +8428,7 @@ public final class net.corda.testing.driver.DriverParameters extends java.lang.O
   public final java.util.List<net.corda.testing.node.NotarySpec> getNotarySpecs()
   @NotNull
   public final net.corda.testing.driver.PortAllocation getPortAllocation()
+  public final boolean getPremigrateH2Database()
   public final boolean getStartNodesInProcess()
   @NotNull
   public final java.util.Map<String, String> getSystemProperties()
@@ -8265,6 +8541,8 @@ public final class net.corda.testing.driver.NodeParameters extends java.lang.Obj
   public <init>(net.corda.core.identity.CordaX500Name, java.util.List, net.corda.testing.driver.VerifierType, java.util.Map, Boolean, String, java.util.Collection, java.util.Map, String, net.corda.core.utilities.NetworkHostAndPort, int, kotlin.jvm.internal.DefaultConstructorMarker)
   @Nullable
   public final net.corda.core.identity.CordaX500Name component1()
+  @Nullable
+  public final net.corda.core.utilities.NetworkHostAndPort component10()
   @NotNull
   public final java.util.List<net.corda.testing.node.User> component2()
   @NotNull
@@ -8300,6 +8578,8 @@ public final class net.corda.testing.driver.NodeParameters extends java.lang.Obj
   public final String getMaximumHeapSize()
   @Nullable
   public final net.corda.core.identity.CordaX500Name getProvidedName()
+  @Nullable
+  public final net.corda.core.utilities.NetworkHostAndPort getRpcAddress()
   @NotNull
   public final java.util.List<net.corda.testing.node.User> getRpcUsers()
   @Nullable
@@ -8435,6 +8715,11 @@ public static final class net.corda.testing.node.ClusterSpec$Raft extends net.co
   @NotNull
   public String toString()
 ##
+public final class net.corda.testing.node.DatabaseSnapshot extends java.lang.Object
+  public final void copyDatabaseSnapshot(java.nio.file.Path)
+  public final java.nio.file.Path databaseFilename(java.nio.file.Path)
+  public static final net.corda.testing.node.DatabaseSnapshot INSTANCE
+##
 @ThreadSafe
 public final class net.corda.testing.node.InMemoryMessagingNetwork extends net.corda.core.serialization.SingletonSerializeAsToken
   public <init>(boolean, net.corda.testing.node.InMemoryMessagingNetwork$ServicePeerAllocationStrategy, org.apache.activemq.artemis.utils.ReusableLatch, kotlin.jvm.internal.DefaultConstructorMarker)

.idea/codeStyles/Project.xml

@@ -14,9 +14,8 @@
     <JetCodeStyleSettings>
       <option name="PACKAGES_TO_USE_STAR_IMPORTS">
         <value>
-          <package name="java.util" withSubpackages="false" static="false" />
+          <package name="kotlinx.android.synthetic" alias="false" withSubpackages="true" />
-          <package name="kotlinx.android.synthetic" withSubpackages="true" static="false" />
+          <package name="tornadofx" alias="false" withSubpackages="false" />
-          <package name="tornadofx" withSubpackages="false" static="false" />
         </value>
       </option>
       <option name="NAME_COUNT_TO_USE_STAR_IMPORT" value="2147483647" />

.idea/codeStyles/codeStyleConfig.xml

@@ -1,6 +1,5 @@
 <component name="ProjectCodeStyleConfiguration">
   <state>
     <option name="USE_PER_PROJECT_SETTINGS" value="true" />
-    <option name="PREFERRED_PROJECT_CODE_STYLE" value="Default" />
   </state>
 </component>

client/rpc/src/smoke-test/kotlin/net/corda/kotlin/rpc/StandaloneCordaRPClientTest.kt

@@ -118,7 +118,7 @@ class StandaloneCordaRPClientTest {
 
         val hash = HashingInputStream(Hashing.sha256(), rpcProxy.openAttachment(id)).use { it ->
             it.copyTo(NULL_OUTPUT_STREAM)
-            SecureHash.SHA256(it.hash().asBytes())
+            SecureHash.createSHA256(it.hash().asBytes())
         }
         assertEquals(attachment.sha256, hash)
     }
@@ -133,7 +133,7 @@ class StandaloneCordaRPClientTest {
 
         val hash = HashingInputStream(Hashing.sha256(), rpcProxy.openAttachment(id)).use { it ->
             it.copyTo(NULL_OUTPUT_STREAM)
-            SecureHash.SHA256(it.hash().asBytes())
+            SecureHash.createSHA256(it.hash().asBytes())
         }
         assertEquals(attachment.sha256, hash)
     }

common/logging/src/main/kotlin/net/corda/common/logging/Constants.kt

@@ -9,4 +9,4 @@ package net.corda.common.logging
  * (originally added to source control for ease of use)
  */
 
-internal const val CURRENT_MAJOR_RELEASE = "4.10-SNAPSHOT"
+internal const val CURRENT_MAJOR_RELEASE = "4.10-SNAPSHOT"

core-deterministic/build.gradle

@@ -1,6 +1,7 @@
 import net.corda.gradle.jarfilter.JarFilterTask
 import net.corda.gradle.jarfilter.MetaFixerTask
 import proguard.gradle.ProGuardTask
+
 import static org.gradle.api.JavaVersion.VERSION_1_8
 
 plugins {
@@ -77,6 +78,7 @@ def patchCore = tasks.register('patchCore', Zip) {
         exclude 'net/corda/core/serialization/internal/AttachmentsHolderImpl.class'
         exclude 'net/corda/core/serialization/internal/CheckpointSerializationFactory*.class'
         exclude 'net/corda/core/internal/rules/*.class'
+        exclude 'net/corda/core/internal/utilities/PrivateInterner*.class'
     }
 
     reproducibleFileOrder = true

core-deterministic/src/main/kotlin/net/corda/core/internal/utilities/PrivateInterner.kt

@@ -0,0 +1,16 @@
+package net.corda.core.internal.utilities
+
+import net.corda.core.KeepForDJVM
+
+@KeepForDJVM
+class PrivateInterner<T>(val verifier: IternabilityVerifier<T> = AlwaysInternableVerifier()) {
+    // DJVM implementation does not intern and does not use Guava
+    fun <S : T> intern(sample: S): S = sample
+
+    @KeepForDJVM
+    companion object {
+        @Suppress("UNUSED_PARAMETER")
+        fun findFor(clazz: Class<*>?): PrivateInterner<Any>? = null
+    }
+}
+

core/build.gradle

@@ -58,7 +58,7 @@ dependencies {
     testCompile "org.assertj:assertj-core:${assertj_version}"
 
     // Guava: Google utilities library.
-    testCompile "com.google.guava:guava:$guava_version"
+    compile "com.google.guava:guava:$guava_version"
 
     // For caches rather than guava
     compile "com.github.ben-manes.caffeine:caffeine:$caffeine_version"

core/src/main/kotlin/net/corda/core/contracts/AttachmentConstraint.kt

@@ -1,5 +1,6 @@
 package net.corda.core.contracts
 
+import net.corda.core.CordaInternal
 import net.corda.core.DoNotImplement
 import net.corda.core.KeepForDJVM
 import net.corda.core.contracts.AlwaysAcceptAttachmentConstraint.isSatisfiedBy
@@ -7,6 +8,8 @@ import net.corda.core.crypto.SecureHash
 import net.corda.core.crypto.isFulfilledBy
 import net.corda.core.internal.AttachmentWithContext
 import net.corda.core.internal.isUploaderTrusted
+import net.corda.core.internal.utilities.Internable
+import net.corda.core.internal.utilities.PrivateInterner
 import net.corda.core.serialization.CordaSerializable
 import net.corda.core.transactions.TransactionBuilder
 import net.corda.core.utilities.loggerFor
@@ -119,7 +122,16 @@ data class SignatureAttachmentConstraint(val key: PublicKey) : AttachmentConstra
         return if (!key.isFulfilledBy(attachment.signerKeys.map { it })) {
             log.warn("Untrusted signing key: expected $key. but contract attachment contains ${attachment.signerKeys}")
             false
-        }
+        } else true
-        else true
+    }
+
+    companion object : Internable<SignatureAttachmentConstraint> {
+        @CordaInternal
+        override val interner = PrivateInterner<SignatureAttachmentConstraint>()
+
+        /**
+         * Factory method to be used in preference to the constructor.
+         */
+        fun create(key: PublicKey) = interner.intern(SignatureAttachmentConstraint(key))
     }
 }

core/src/main/kotlin/net/corda/core/crypto/CompositeSignature.kt

@@ -3,7 +3,13 @@ package net.corda.core.crypto
 import net.corda.core.KeepForDJVM
 import net.corda.core.serialization.deserialize
 import java.io.ByteArrayOutputStream
-import java.security.*
+import java.security.InvalidAlgorithmParameterException
+import java.security.InvalidKeyException
+import java.security.PrivateKey
+import java.security.Provider
+import java.security.PublicKey
+import java.security.Signature
+import java.security.SignatureException
 import java.security.spec.AlgorithmParameterSpec
 
 /**
@@ -80,7 +86,7 @@ class CompositeSignature : Signature(SIGNATURE_ALGORITHM) {
         fun engineVerify(sigBytes: ByteArray): Boolean {
             val sig = sigBytes.deserialize<CompositeSignaturesWithKeys>()
             return if (verifyKey.isFulfilledBy(sig.sigs.map { it.by })) {
-                val clearData = SecureHash.SHA256(buffer.toByteArray())
+                val clearData = SecureHash.createSHA256(buffer.toByteArray())
                 sig.sigs.all { it.isValid(clearData) }
             } else {
                 false

core/src/main/kotlin/net/corda/core/crypto/Crypto.kt

@@ -5,11 +5,12 @@ import net.corda.core.DeleteForDJVM
 import net.corda.core.KeepForDJVM
 import net.corda.core.crypto.internal.AliasPrivateKey
 import net.corda.core.crypto.internal.Instances.withSignature
-import net.corda.core.crypto.internal.`id-Curve25519ph`
 import net.corda.core.crypto.internal.bouncyCastlePQCProvider
 import net.corda.core.crypto.internal.cordaBouncyCastleProvider
 import net.corda.core.crypto.internal.cordaSecurityProvider
+import net.corda.core.crypto.internal.`id-Curve25519ph`
 import net.corda.core.crypto.internal.providerMap
+import net.corda.core.internal.utilities.PrivateInterner
 import net.corda.core.serialization.serialize
 import net.i2p.crypto.eddsa.EdDSAEngine
 import net.i2p.crypto.eddsa.EdDSAPrivateKey
@@ -710,7 +711,8 @@ object Crypto {
             keyPairGenerator.initialize(signatureScheme.algSpec, newSecureRandom())
         else
             keyPairGenerator.initialize(signatureScheme.keySize!!, newSecureRandom())
-        return keyPairGenerator.generateKeyPair()
+        val newKeyPair = keyPairGenerator.generateKeyPair()
+        return KeyPair(internPublicKey(newKeyPair.public), newKeyPair.private)
     }
 
     /**
@@ -840,7 +842,7 @@ object Crypto {
         val publicKeySpec = ECPublicKeySpec(pointQ, parameterSpec)
         val publicKeyD = BCECPublicKey(privateKey.algorithm, publicKeySpec, BouncyCastleProvider.CONFIGURATION)
 
-        return KeyPair(publicKeyD, privateKeyD)
+        return KeyPair(internPublicKey(publicKeyD), privateKeyD)
     }
 
     // Deterministically generate an EdDSA key.
@@ -853,7 +855,7 @@ object Crypto {
         val bytes = macBytes.copyOf(params.curve.field.getb() / 8) // Need to pad the entropy to the valid seed length.
         val privateKeyD = EdDSAPrivateKeySpec(bytes, params)
         val publicKeyD = EdDSAPublicKeySpec(privateKeyD.a, params)
-        return KeyPair(EdDSAPublicKey(publicKeyD), EdDSAPrivateKey(privateKeyD))
+        return KeyPair(internPublicKey(EdDSAPublicKey(publicKeyD)), EdDSAPrivateKey(privateKeyD))
     }
 
     /**
@@ -892,7 +894,7 @@ object Crypto {
         val bytes = entropy.toByteArray().copyOf(params.curve.field.getb() / 8) // Need to pad the entropy to the valid seed length.
         val priv = EdDSAPrivateKeySpec(bytes, params)
         val pub = EdDSAPublicKeySpec(priv.a, params)
-        return KeyPair(EdDSAPublicKey(pub), EdDSAPrivateKey(priv))
+        return KeyPair(internPublicKey(EdDSAPublicKey(pub)), EdDSAPrivateKey(priv))
     }
 
     // Custom key pair generator from an entropy required for various tests. It is similar to deriveKeyPairECDSA,
@@ -918,7 +920,7 @@ object Crypto {
         val publicKeySpec = ECPublicKeySpec(pointQ, parameterSpec)
         val pub = BCECPublicKey("EC", publicKeySpec, BouncyCastleProvider.CONFIGURATION)
 
-        return KeyPair(pub, priv)
+        return KeyPair(internPublicKey(pub), priv)
     }
 
     // Compute the HMAC-SHA512 using a privateKey as the MAC_key and a seed ByteArray.
@@ -990,11 +992,14 @@ object Crypto {
         }
     }
 
+    private val interner = PrivateInterner<PublicKey>()
+    private fun internPublicKey(key: PublicKey): PublicKey = interner.intern(key)
+
     private fun convertIfBCEdDSAPublicKey(key: PublicKey): PublicKey {
-        return when (key) {
+        return internPublicKey(when (key) {
             is BCEdDSAPublicKey -> EdDSAPublicKey(X509EncodedKeySpec(key.encoded))
             else -> key
-        }
+        })
     }
 
     private fun convertIfBCEdDSAPrivateKey(key: PrivateKey): PrivateKey {
@@ -1026,11 +1031,11 @@ object Crypto {
     @JvmStatic
     fun toSupportedPublicKey(key: PublicKey): PublicKey {
         return when (key) {
-            is BCECPublicKey -> key
+            is BCECPublicKey -> internPublicKey(key)
-            is BCRSAPublicKey -> key
+            is BCRSAPublicKey -> internPublicKey(key)
-            is BCSphincs256PublicKey -> key
+            is BCSphincs256PublicKey -> internPublicKey(key)
-            is EdDSAPublicKey -> key
+            is EdDSAPublicKey -> internPublicKey(key)
-            is CompositeKey -> key
+            is CompositeKey -> internPublicKey(key)
             is BCEdDSAPublicKey -> convertIfBCEdDSAPublicKey(key)
             else -> decodePublicKey(key.encoded)
         }

core/src/main/kotlin/net/corda/core/crypto/SecureHash.kt

@@ -3,9 +3,12 @@
 package net.corda.core.crypto
 
 import io.netty.util.concurrent.FastThreadLocal
+import net.corda.core.CordaInternal
 import net.corda.core.DeleteForDJVM
 import net.corda.core.KeepForDJVM
 import net.corda.core.crypto.internal.DigestAlgorithmFactory
+import net.corda.core.internal.utilities.Internable
+import net.corda.core.internal.utilities.PrivateInterner
 import net.corda.core.serialization.CordaSerializable
 import net.corda.core.utilities.OpaqueBytes
 import net.corda.core.utilities.parseAsHex
@@ -66,7 +69,7 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
         }
 
         override fun generate(data: ByteArray): SecureHash {
-            return HASH(algorithm, digestAs(algorithm, data))
+            return interner.intern(HASH(algorithm, digestAs(algorithm, data)))
         }
     }
 
@@ -110,7 +113,7 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
         return if(concatAlgorithm == SHA2_256) {
             concatBytes.sha256()
         } else {
-            HASH(concatAlgorithm, digestAs(concatAlgorithm, concatBytes))
+            interner.intern(HASH(concatAlgorithm, digestAs(concatAlgorithm, concatBytes)))
         }
     }
 
@@ -121,12 +124,15 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
     fun reHash() : SecureHash = hashAs(algorithm, bytes)
 
     // Like static methods in Java, except the 'companion' is a singleton that can have state.
-    companion object {
+    companion object : Internable<SecureHash> {
         const val SHA2_256 = "SHA-256"
         const val SHA2_384 = "SHA-384"
         const val SHA2_512 = "SHA-512"
         const val DELIMITER = ':'
 
+        @CordaInternal
+        override val interner = PrivateInterner<SecureHash>()
+
         /**
          * Converts a SecureHash hash value represented as a {algorithm:}hexadecimal [String] into a [SecureHash].
          * @param str An optional algorithm id followed by a delimiter and the sequence of hexadecimal digits that represents a hash value.
@@ -157,7 +163,7 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
             val digestLength = digestFor(algorithm).digestLength
             val data = value.parseAsHex()
             return when (data.size) {
-                digestLength -> HASH(algorithm, data)
+                digestLength -> interner.intern(HASH(algorithm, data))
                 else -> throw IllegalArgumentException("Provided string is ${data.size} bytes not $digestLength bytes in hex: $value")
             }
         }
@@ -171,12 +177,18 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
         fun parse(str: String?): SHA256 {
             return str?.toUpperCase()?.parseAsHex()?.let {
                 when (it.size) {
-                    32 -> SHA256(it)
+                    32 -> interner.intern(SHA256(it))
                     else -> throw IllegalArgumentException("Provided string is ${it.size} bytes not 32 bytes in hex: $str")
                 }
             } ?: throw IllegalArgumentException("Provided string is null")
         }
 
+        /**
+         * Factory method for SHA256 to be used in preference to the constructor.
+         */
+        @JvmStatic
+        fun createSHA256(bytes: ByteArray): SHA256 = interner.intern(SHA256(bytes))
+
         private val messageDigests: ConcurrentMap<String, DigestSupplier> = ConcurrentHashMap()
 
         private fun digestFor(algorithm: String): DigestSupplier {
@@ -202,9 +214,9 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
         fun hashAs(algorithm: String, bytes: ByteArray): SecureHash {
             val hashBytes = digestAs(algorithm, bytes)
             return if (algorithm == SHA2_256) {
-                SHA256(hashBytes)
+                interner.intern(SHA256(hashBytes))
             } else {
-                HASH(algorithm, hashBytes)
+                interner.intern(HASH(algorithm, hashBytes))
             }
         }
 
@@ -222,7 +234,7 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
             } else {
                 val digest = digestFor(algorithm).get()
                 val hash = digest.componentDigest(bytes)
-                HASH(algorithm, hash)
+                interner.intern(HASH(algorithm, hash))
             }
         }
 
@@ -240,7 +252,7 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
             } else {
                 val digest = digestFor(algorithm).get()
                 val hash = digest.nonceDigest(bytes)
-                HASH(algorithm, hash)
+                interner.intern(HASH(algorithm, hash))
             }
         }
 
@@ -249,7 +261,7 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
          * @param bytes The [ByteArray] to hash.
          */
         @JvmStatic
-        fun sha256(bytes: ByteArray) = SHA256(digestAs(SHA2_256, bytes))
+        fun sha256(bytes: ByteArray) = interner.intern(SHA256(digestAs(SHA2_256, bytes)))
 
         /**
          * Computes the SHA-256 hash of the [ByteArray], and then computes the SHA-256 hash of the hash.
@@ -282,7 +294,7 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
                 randomSHA256()
             } else {
                 val digest = digestFor(algorithm)
-                HASH(algorithm, digest.get().digest(secureRandomBytes(digest.digestLength)))
+                interner.intern(HASH(algorithm, digest.get().digest(secureRandomBytes(digest.digestLength))))
             }
         }
 
@@ -291,7 +303,7 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
          * This field provides more intuitive access from Java.
          */
         @JvmField
-        val zeroHash: SHA256 = SHA256(ByteArray(32) { 0.toByte() })
+        val zeroHash: SHA256 = interner.intern(SHA256(ByteArray(32) { 0.toByte() }))
 
         /**
          * A SHA-256 hash value consisting of 32 0x00 bytes.
@@ -305,7 +317,7 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
          * This field provides more intuitive access from Java.
          */
         @JvmField
-        val allOnesHash: SHA256 = SHA256(ByteArray(32) { 255.toByte() })
+        val allOnesHash: SHA256 = interner.intern(SHA256(ByteArray(32) { 255.toByte() }))
 
         /**
          * A SHA-256 hash value consisting of 32 0xFF bytes.
@@ -323,8 +335,8 @@ sealed class SecureHash(bytes: ByteArray) : OpaqueBytes(bytes) {
             return hashConstants.getOrPut(algorithm) {
                 val digestLength = digestFor(algorithm).digestLength
                 HashConstants(
-                        zero = HASH(algorithm, ByteArray(digestLength)),
+                        zero = interner.intern(HASH(algorithm, ByteArray(digestLength))),
-                        allOnes = HASH(algorithm, ByteArray(digestLength) { 255.toByte() })
+                        allOnes = interner.intern(HASH(algorithm, ByteArray(digestLength) { 255.toByte() }))
                 )
             }
         }

core/src/main/kotlin/net/corda/core/identity/AbstractParty.kt

@@ -1,8 +1,12 @@
 package net.corda.core.identity
 
+import net.corda.core.CordaInternal
 import net.corda.core.DoNotImplement
 import net.corda.core.contracts.PartyAndReference
 import net.corda.core.flows.Destination
+import net.corda.core.internal.utilities.Internable
+import net.corda.core.internal.utilities.IternabilityVerifier
+import net.corda.core.internal.utilities.PrivateInterner
 import net.corda.core.serialization.CordaSerializable
 import net.corda.core.utilities.OpaqueBytes
 import java.security.PublicKey
@@ -31,4 +35,15 @@ abstract class AbstractParty(val owningKey: PublicKey): Destination {
      * ledger.
      */
     fun ref(vararg bytes: Byte) = ref(OpaqueBytes.of(*bytes))
+
+    @CordaInternal
+    companion object : Internable<AbstractParty> {
+        @CordaInternal
+        override val interner = PrivateInterner<AbstractParty>(object : IternabilityVerifier<AbstractParty> {
+            override fun choose(original: AbstractParty, interned: AbstractParty): AbstractParty {
+                // Because Party does not compare name in equals(), don't intern if there's a clash
+                return if (original.nameOrNull() != interned.nameOrNull()) original else interned
+            }
+        })
+    }
 }

core/src/main/kotlin/net/corda/core/identity/AnonymousParty.kt

@@ -22,4 +22,11 @@ class AnonymousParty(owningKey: PublicKey) : Destination, AbstractParty(owningKe
     override fun nameOrNull(): CordaX500Name? = null
     override fun ref(bytes: OpaqueBytes): PartyAndReference = PartyAndReference(this, bytes)
     override fun toString() = "Anonymous(${owningKey.toStringShort()})"
+
+    companion object {
+        /**
+         * Factory method to be used in preference to the constructor.
+         */
+        fun create(owningKey: PublicKey): AnonymousParty = interner.intern(AnonymousParty(owningKey))
+    }
 }

core/src/main/kotlin/net/corda/core/identity/CordaX500Name.kt

@@ -1,10 +1,13 @@
 package net.corda.core.identity
 
+import net.corda.core.CordaInternal
 import net.corda.core.KeepForDJVM
 import net.corda.core.internal.LegalNameValidator
 import net.corda.core.internal.toAttributesMap
 import net.corda.core.internal.toX500Name
 import net.corda.core.internal.unspecifiedCountry
+import net.corda.core.internal.utilities.Internable
+import net.corda.core.internal.utilities.PrivateInterner
 import net.corda.core.serialization.CordaSerializable
 import org.bouncycastle.asn1.x500.style.BCStyle
 import java.util.*
@@ -68,7 +71,7 @@ data class CordaX500Name(val commonName: String?,
         }
     }
 
-    companion object {
+    companion object : Internable<CordaX500Name> {
         @Deprecated("Not Used")
         const val LENGTH_COUNTRY = 2
         const val MAX_LENGTH_ORGANISATION = 128
@@ -80,6 +83,9 @@ data class CordaX500Name(val commonName: String?,
         private val supportedAttributes = setOf(BCStyle.O, BCStyle.C, BCStyle.L, BCStyle.CN, BCStyle.ST, BCStyle.OU)
         private val countryCodes: Set<String> = setOf(*Locale.getISOCountries(), unspecifiedCountry)
 
+        @CordaInternal
+        override val interner = PrivateInterner<CordaX500Name>()
+
         @JvmStatic
         fun build(principal: X500Principal): CordaX500Name {
             val attrsMap = principal.toAttributesMap(supportedAttributes)
@@ -89,7 +95,7 @@ data class CordaX500Name(val commonName: String?,
             val L = requireNotNull(attrsMap[BCStyle.L]) { "Corda X.500 names must include an L attribute" }
             val ST = attrsMap[BCStyle.ST]
             val C = requireNotNull(attrsMap[BCStyle.C]) { "Corda X.500 names must include an C attribute" }
-            return CordaX500Name(CN, OU, O, L, ST, C)
+            return interner.intern(CordaX500Name(CN, OU, O, L, ST, C))
         }
 
         @JvmStatic

core/src/main/kotlin/net/corda/core/identity/Party.kt

@@ -45,4 +45,16 @@ class Party(val name: CordaX500Name, owningKey: PublicKey) : Destination, Abstra
     override fun ref(bytes: OpaqueBytes): PartyAndReference = PartyAndReference(this, bytes)
     override fun toString() = name.toString()
     fun description() = "$name (owningKey = ${owningKey.toStringShort()})"
+
+    companion object {
+        /**
+         * Factory method to be used in preference to the constructor.
+         */
+        fun create(name: CordaX500Name, owningKey: PublicKey): Party = interner.intern(Party(name, owningKey))
+
+        /**
+         * Factory method to be used in preference to the constructor.
+         */
+        fun create(certificate: X509Certificate): Party = interner.intern(Party(certificate))
+    }
 }

core/src/main/kotlin/net/corda/core/identity/PartyAndCertificate.kt

@@ -6,7 +6,11 @@ import net.corda.core.internal.uncheckedCast
 import net.corda.core.internal.validate
 import net.corda.core.serialization.CordaSerializable
 import java.security.PublicKey
-import java.security.cert.*
+import java.security.cert.CertPath
+import java.security.cert.CertPathValidatorException
+import java.security.cert.PKIXCertPathValidatorResult
+import java.security.cert.TrustAnchor
+import java.security.cert.X509Certificate
 
 /**
  * A full party plus the X.509 certificate and path linking the party back to a trust root. Equality of
@@ -29,7 +33,7 @@ class PartyAndCertificate(val certPath: CertPath) {
     }
 
     @Transient
-    val party: Party = Party(certificate)
+    val party: Party = Party.create(certificate)
 
     val owningKey: PublicKey get() = party.owningKey
     val name: CordaX500Name get() = party.name

core/src/main/kotlin/net/corda/core/internal/InternalUtils.kt

@@ -77,7 +77,6 @@ import java.util.stream.StreamSupport
 import java.util.zip.Deflater
 import java.util.zip.ZipEntry
 import java.util.zip.ZipOutputStream
-import kotlin.collections.LinkedHashSet
 import kotlin.math.roundToLong
 import kotlin.reflect.KClass
 import kotlin.reflect.full.createInstance
@@ -165,7 +164,7 @@ fun InputStream.hash(): SecureHash {
             }
             md.update(buffer, 0, count)
         }
-        SecureHash.SHA256(md.digest())
+        SecureHash.createSHA256(md.digest())
     }
 }
 

core/src/main/kotlin/net/corda/core/internal/utilities/Internable.kt

@@ -0,0 +1,24 @@
+package net.corda.core.internal.utilities
+
+import net.corda.core.CordaInternal
+import net.corda.core.KeepForDJVM
+
+@KeepForDJVM
+interface Internable<T> {
+    @CordaInternal
+    val interner: PrivateInterner<T>
+}
+
+@KeepForDJVM
+@CordaInternal
+interface IternabilityVerifier<T> {
+    // If a type being interned has a slightly dodgy equality check, the more strict rules you probably
+    // want to apply to interning can be enforced here.
+    fun choose(original: T, interned: T): T
+}
+
+@KeepForDJVM
+@CordaInternal
+class AlwaysInternableVerifier<T> : IternabilityVerifier<T> {
+    override fun choose(original: T, interned: T): T = interned
+}

core/src/main/kotlin/net/corda/core/internal/utilities/PrivateInterner.kt

@@ -0,0 +1,69 @@
+package net.corda.core.internal.utilities
+
+import com.google.common.collect.Interners
+import net.corda.core.CordaInternal
+import net.corda.core.internal.packageNameOrNull
+import net.corda.core.internal.uncheckedCast
+import net.corda.core.serialization.CordaSerializable
+import kotlin.reflect.full.companionObjectInstance
+
+/**
+ * This class converts instances supplied to [intern] to a common instance within the JVM, amongst all those
+ * instances that have been submitted.  It uses weak references to avoid memory leaks.
+ *
+ * NOTE: the Guava interners are Beta, so upgrading Guava may result in us having to adapt this code.
+ *
+ * System properties allow disabling, in the event an issue is uncovered in a live environment.  The
+ * correct default for the concurrency setting is the result of performance evaluation.
+ */
+@CordaInternal
+class PrivateInterner<T>(val verifier: IternabilityVerifier<T> = AlwaysInternableVerifier()) {
+    companion object {
+        // This value is the default in Guava, and performance testing didn't reveal a need to change
+        private const val DEFAULT_CONCURRENCY_LEVEL = 4
+        private val CONCURRENCY_LEVEL = Integer.getInteger("net.corda.core.intern.concurrency", DEFAULT_CONCURRENCY_LEVEL).toInt()
+        private val DISABLE = java.lang.Boolean.getBoolean("net.corda.core.intern.disable")
+
+        /**
+         * This will look at the companion object of a class, and on the super class companion object,
+         * to see if they implement [Internable], in which case there is a [PrivateInterner] instance
+         * available to do interning.  Tolerant of null class references and a lack of companion objects.
+         */
+        @Suppress("ComplexMethod")
+        fun findFor(clazz: Class<*>?): PrivateInterner<Any>? {
+            fun hasCordaSerializable(type: Class<*>): Boolean {
+                return type.isAnnotationPresent(CordaSerializable::class.java)
+                        || type.interfaces.any(::hasCordaSerializable)
+                        || (type.superclass != null && hasCordaSerializable(type.superclass))
+            }
+
+            fun isSerializableCore(clazz: Class<*>): Boolean {
+                if (!(clazz.packageNameOrNull?.startsWith("net.corda.core") ?: false)) return false
+                return hasCordaSerializable(clazz)
+            }
+
+            fun findInterner(clazz: Class<*>?): PrivateInterner<Any>? {
+                // Kotlin reflection has a habit of throwing exceptions, so protect just in case.
+                try {
+                    return clazz?.kotlin?.companionObjectInstance?.let {
+                        (it as? Internable<*>)?.let {
+                            uncheckedCast(it.interner)
+                        }
+                    }
+                } catch (_: Throwable) {
+                    return null
+                }
+            }
+            return if (clazz != null) {
+                // We try not to ruffle the feathers of kotlin reflection by avoiding throwing all types at it.
+                if (!isSerializableCore(clazz)) return null
+                findInterner(clazz) ?: findInterner(clazz.superclass)
+            } else null
+        }
+    }
+
+    private val interner = Interners.newBuilder().weak().concurrencyLevel(CONCURRENCY_LEVEL).build<T>()
+
+    fun <S : T> intern(sample: S): S = if (DISABLE) sample else uncheckedCast(verifier.choose(sample, interner.intern(sample)))
+}
+

core/src/main/kotlin/net/corda/core/node/services/VaultService.kt

@@ -176,7 +176,7 @@ class Vault<out T : ContractState>(val states: Iterable<StateAndRef<T>>) {
                     Type.ALWAYS_ACCEPT -> ConstraintInfo(AlwaysAcceptAttachmentConstraint)
                     Type.HASH -> ConstraintInfo(HashAttachmentConstraint(SecureHash.create(data!!.toHexString())))
                     Type.CZ_WHITELISTED -> ConstraintInfo(WhitelistedByZoneAttachmentConstraint)
-                    Type.SIGNATURE -> ConstraintInfo(SignatureAttachmentConstraint(Crypto.decodePublicKey(data!!)))
+                    Type.SIGNATURE -> ConstraintInfo(SignatureAttachmentConstraint.create(Crypto.decodePublicKey(data!!)))
                 }
             }
         }

core/src/main/kotlin/net/corda/core/serialization/internal/AttachmentsClassLoader.kt

@@ -47,6 +47,9 @@ import java.util.Locale
 import java.util.ServiceLoader
 import java.util.WeakHashMap
 import java.util.function.Function
+import kotlin.collections.component1
+import kotlin.collections.component2
+import kotlin.collections.set
 
 /**
  * A custom ClassLoader that knows how to load classes from a set of attachments. The attachments themselves only
@@ -164,7 +167,7 @@ class AttachmentsClassLoader(attachments: List<Attachment>,
             if(read <= 0) break
             md.update(ctx.buffer, 0, read)
         }
-        return SecureHash.SHA256(md.digest())
+        return SecureHash.createSHA256(md.digest())
     }
 
     private fun isZipOrJar(attachment: Attachment) = attachment.openAsJAR().use { jar ->

core/src/main/kotlin/net/corda/core/transactions/TransactionBuilder.kt

@@ -650,7 +650,8 @@ open class TransactionBuilder(
     }
 
     private fun makeSignatureAttachmentConstraint(attachmentSigners: List<PublicKey>) =
-            SignatureAttachmentConstraint(CompositeKey.Builder().addKeys(attachmentSigners).build())
+            SignatureAttachmentConstraint.create(CompositeKey.Builder().addKeys(attachmentSigners)
+                    .build())
 
     private fun getInstalledContractAttachmentId(
             contractClassName: String,

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/kryo/CordaClassResolver.kt

@@ -1,17 +1,23 @@
 package net.corda.nodeapi.internal.serialization.kryo
 
-import com.esotericsoftware.kryo.*
+import com.esotericsoftware.kryo.DefaultSerializer
+import com.esotericsoftware.kryo.Kryo
+import com.esotericsoftware.kryo.KryoException
+import com.esotericsoftware.kryo.KryoSerializable
+import com.esotericsoftware.kryo.Registration
+import com.esotericsoftware.kryo.Serializer
 import com.esotericsoftware.kryo.io.Input
 import com.esotericsoftware.kryo.io.Output
 import com.esotericsoftware.kryo.serializers.FieldSerializer
 import com.esotericsoftware.kryo.util.DefaultClassResolver
 import com.esotericsoftware.kryo.util.Util
 import net.corda.core.internal.kotlinObjectInstance
+import net.corda.core.internal.utilities.PrivateInterner
 import net.corda.core.internal.writer
-import net.corda.core.serialization.internal.CheckpointSerializationContext
 import net.corda.core.serialization.ClassWhitelist
-import net.corda.core.utilities.contextLogger
 import net.corda.core.serialization.internal.AttachmentsClassLoader
+import net.corda.core.serialization.internal.CheckpointSerializationContext
+import net.corda.core.utilities.contextLogger
 import net.corda.serialization.internal.MutableClassWhitelist
 import net.corda.serialization.internal.TransientClassWhiteList
 import net.corda.serialization.internal.amqp.hasCordaSerializable
@@ -19,8 +25,11 @@ import java.io.PrintWriter
 import java.lang.reflect.Modifier.isAbstract
 import java.nio.charset.StandardCharsets.UTF_8
 import java.nio.file.Paths
-import java.nio.file.StandardOpenOption.*
+import java.nio.file.StandardOpenOption.APPEND
-import java.util.*
+import java.nio.file.StandardOpenOption.CREATE
+import java.nio.file.StandardOpenOption.WRITE
+import java.util.ArrayList
+import java.util.Collections
 
 /**
  * Corda specific class resolver which enables extra customisation for the purposes of serialization using Kryo
@@ -86,7 +95,7 @@ class CordaClassResolver(serializationContext: CheckpointSerializationContext) :
                 kotlin.jvm.internal.Lambda::class.java.isAssignableFrom(targetType) -> // Kotlin lambdas extend this class and any captured variables are stored in synthetic fields
                     FieldSerializer<Any>(kryo, targetType).apply { setIgnoreSyntheticFields(false) }
                 Throwable::class.java.isAssignableFrom(targetType) -> ThrowableSerializer(kryo, targetType)
-                else -> kryo.getDefaultSerializer(targetType)
+                else -> maybeWrapForInterning(kryo.getDefaultSerializer(targetType), targetType)
             }
             return register(Registration(targetType, serializer, NAME.toInt()))
         } finally {
@@ -94,6 +103,11 @@ class CordaClassResolver(serializationContext: CheckpointSerializationContext) :
         }
     }
 
+    private fun maybeWrapForInterning(serializer: Serializer<Any>, targetType: Class<*>): Serializer<Any> {
+        val interner = PrivateInterner.findFor(targetType)
+        return if (interner != null) InterningSerializer(serializer, interner) else serializer
+    }
+
     override fun writeName(output: Output, type: Class<*>, registration: Registration) {
         super.writeName(output, registration.type ?: type, registration)
     }
@@ -104,6 +118,11 @@ class CordaClassResolver(serializationContext: CheckpointSerializationContext) :
         override fun write(kryo: Kryo, output: Output, obj: Any) = Unit
     }
 
+    private class InterningSerializer(private val delegate: Serializer<Any>, private val interner: PrivateInterner<Any>) : Serializer<Any>() {
+        override fun read(kryo: Kryo, input: Input, type: Class<Any>): Any = interner.intern(delegate.read(kryo, input, type))
+        override fun write(kryo: Kryo, output: Output, obj: Any) = delegate.write(kryo, output, obj)
+    }
+
     // We don't allow the annotation for classes in attachments for now.  The class will be on the main classpath if we have the CorDapp installed.
     // We also do not allow extension of KryoSerializable for annotated classes, or combination with @DefaultSerializer for custom serialisation.
     // TODO: Later we can support annotations on attachment classes and spin up a proxy via bytecode that we know is harmless.

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/kryo/DefaultKryoCustomizer.kt

@@ -59,9 +59,8 @@ import java.security.PrivateKey
 import java.security.PublicKey
 import java.security.cert.CertPath
 import java.security.cert.X509Certificate
-import java.util.Arrays
+import java.util.*
-import java.util.BitSet
+import kotlin.collections.ArrayList
-import java.util.ServiceLoader
 
 object DefaultKryoCustomizer {
     private val serializationWhitelists: List<SerializationWhitelist> by lazy {
@@ -233,7 +232,7 @@ object DefaultKryoCustomizer {
         @Suppress("UNCHECKED_CAST")
         override fun read(kryo: Kryo, input: Input, type: Class<ContractAttachment>): ContractAttachment {
             if (kryo.serializationContext() != null) {
-                val attachmentHash = SecureHash.SHA256(input.readBytes(32))
+                val attachmentHash = SecureHash.createSHA256(input.readBytes(32))
                 val contract = input.readString()
                 val additionalContracts = kryo.readClassAndObject(input) as Set<ContractClassName>
                 val uploader = input.readString()

node-api/src/test/kotlin/net/corda/nodeapi/internal/serialization/kryo/KryoTests.kt

@@ -9,22 +9,38 @@ import com.google.common.primitives.Ints
 import com.nhaarman.mockito_kotlin.doReturn
 import com.nhaarman.mockito_kotlin.whenever
 import net.corda.core.contracts.PrivacySalt
-import net.corda.core.crypto.*
+import net.corda.core.contracts.SignatureAttachmentConstraint
+import net.corda.core.crypto.Crypto
+import net.corda.core.crypto.SecureHash
+import net.corda.core.crypto.SignableData
+import net.corda.core.crypto.SignatureMetadata
+import net.corda.core.crypto.generateKeyPair
+import net.corda.core.crypto.sha256
+import net.corda.core.crypto.sign
+import net.corda.core.identity.AnonymousParty
+import net.corda.core.identity.CordaX500Name
+import net.corda.core.identity.Party
 import net.corda.core.internal.FetchDataFlow
-import net.corda.core.serialization.*
+import net.corda.core.serialization.CordaSerializable
+import net.corda.core.serialization.EncodingWhitelist
 import net.corda.core.serialization.internal.CheckpointSerializationContext
 import net.corda.core.serialization.internal.checkpointDeserialize
 import net.corda.core.serialization.internal.checkpointSerialize
 import net.corda.core.utilities.ByteSequence
 import net.corda.core.utilities.ProgressTracker
 import net.corda.core.utilities.sequence
-import net.corda.serialization.internal.*
+import net.corda.coretesting.internal.rigorousMock
+import net.corda.serialization.internal.AllWhitelist
+import net.corda.serialization.internal.CheckpointSerializationContextImpl
+import net.corda.serialization.internal.CordaSerializationEncoding
+import net.corda.serialization.internal.encodingNotPermittedFormat
 import net.corda.testing.core.ALICE_NAME
 import net.corda.testing.core.TestIdentity
 import net.corda.testing.core.internal.CheckpointSerializationEnvironmentRule
-import net.corda.coretesting.internal.rigorousMock
 import org.apache.commons.lang3.SystemUtils
-import org.assertj.core.api.Assertions.*
+import org.assertj.core.api.Assertions.assertThat
+import org.assertj.core.api.Assertions.assertThatThrownBy
+import org.assertj.core.api.Assertions.catchThrowable
 import org.junit.Assert.assertArrayEquals
 import org.junit.Assert.assertEquals
 import org.junit.Before
@@ -36,9 +52,13 @@ import org.junit.runners.Parameterized.Parameters
 import org.slf4j.LoggerFactory
 import java.io.InputStream
 import java.time.Instant
-import java.util.*
+import java.util.Collections
-import kotlin.collections.ArrayList
+import java.util.Random
-import kotlin.test.*
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertNotNull
+import kotlin.test.assertSame
+import kotlin.test.assertTrue
 
 @RunWith(Parameterized::class)
 class KryoTests(private val compression: CordaSerializationEncoding?) {
@@ -129,6 +149,7 @@ class KryoTests(private val compression: CordaSerializationEncoding?) {
         val deserialisedSignature = deserialisedKeyPair.sign(bitsToSign)
         deserialisedSignature.verify(bitsToSign)
         assertThatThrownBy { deserialisedSignature.verify(wrongBits) }
+        assertSame(keyPair.public, deserialisedKeyPair.public)
     }
 
     @Test(timeout=300_000)
@@ -178,7 +199,7 @@ class KryoTests(private val compression: CordaSerializationEncoding?) {
     }
 
     @Test(timeout=300_000)
-	fun `serialize - deserialize SignableData`() {
+    fun `serialize - deserialize SignableData`() {
         val testString = "Hello World"
         val testBytes = testString.toByteArray()
 
@@ -186,15 +207,33 @@ class KryoTests(private val compression: CordaSerializationEncoding?) {
         val serializedMetaData = meta.checkpointSerialize(context).bytes
         val meta2 = serializedMetaData.checkpointDeserialize<SignableData>(context)
         assertEquals(meta2, meta)
+        assertSame(meta.txId, meta2.txId)
     }
 
-    @Test(timeout=300_000)
+    @Test(timeout = 300_000)
-	fun `serialize - deserialize Logger`() {
+    fun `serialize - deserialize internables`() {
+        val list: List<Any> = listOf(
+                SecureHash.randomSHA256(),
+                CordaX500Name.parse("O=bank A, L=New York, C=DE, OU=Org Unit, CN=Service Name"),
+                Party.create(CordaX500Name.parse("O=bank A, L=New York, C=DE, OU=Org Unit, CN=Service Name"), Crypto.generateKeyPair().public),
+                AnonymousParty.create(Crypto.generateKeyPair().public),
+                SignatureAttachmentConstraint.create(Crypto.generateKeyPair().public)
+        )
+
+        val serializedList = list.checkpointSerialize(context).bytes
+        val list2 = serializedList.checkpointDeserialize<List<Any>>(context)
+        list.zip(list2).forEach { (original, deserialized) ->
+            assertSame(original, deserialized, "${original.javaClass} not interned")
+        }
+    }
+
+    @Test(timeout = 300_000)
+    fun `serialize - deserialize Logger`() {
         val storageContext: CheckpointSerializationContext = context
         val logger = LoggerFactory.getLogger("aName")
         val logger2 = logger.checkpointSerialize(storageContext).checkpointDeserialize(storageContext)
         assertEquals(logger.name, logger2.name)
-        assertTrue(logger === logger2)
+        assertSame(logger, logger2)
     }
 
     @CordaSerializable

node/src/main/kotlin/net/corda/node/services/persistence/NodeAttachmentService.kt

@@ -12,10 +12,21 @@ import net.corda.core.contracts.ContractAttachment
 import net.corda.core.contracts.ContractClassName
 import net.corda.core.crypto.SecureHash
 import net.corda.core.crypto.sha256
-import net.corda.core.internal.*
+import net.corda.core.internal.AbstractAttachment
+import net.corda.core.internal.DEPLOYED_CORDAPP_UPLOADER
+import net.corda.core.internal.FetchAttachmentsFlow
+import net.corda.core.internal.JarSignatureCollector
+import net.corda.core.internal.NamedCacheFactory
+import net.corda.core.internal.P2P_UPLOADER
+import net.corda.core.internal.RPC_UPLOADER
+import net.corda.core.internal.TRUSTED_UPLOADERS
+import net.corda.core.internal.UNKNOWN_UPLOADER
 import net.corda.core.internal.Version
+import net.corda.core.internal.VisibleForTesting
 import net.corda.core.internal.cordapp.CordappImpl.Companion.CORDAPP_CONTRACT_VERSION
 import net.corda.core.internal.cordapp.CordappImpl.Companion.DEFAULT_CORDAPP_VERSION
+import net.corda.core.internal.isUploaderTrusted
+import net.corda.core.internal.readFully
 import net.corda.core.internal.utilities.ZipBombDetector
 import net.corda.core.node.ServicesForResolution
 import net.corda.core.node.services.AttachmentId
@@ -23,7 +34,11 @@ import net.corda.core.node.services.vault.AttachmentQueryCriteria
 import net.corda.core.node.services.vault.AttachmentSort
 import net.corda.core.node.services.vault.Builder
 import net.corda.core.node.services.vault.Sort
-import net.corda.core.serialization.*
+import net.corda.core.serialization.CordaSerializable
+import net.corda.core.serialization.SerializationToken
+import net.corda.core.serialization.SerializeAsToken
+import net.corda.core.serialization.SerializeAsTokenContext
+import net.corda.core.serialization.SingletonSerializeAsToken
 import net.corda.core.utilities.contextLogger
 import net.corda.node.services.vault.HibernateAttachmentQueryCriteriaParser
 import net.corda.node.utilities.InfrequentlyMutatedCache
@@ -46,7 +61,17 @@ import java.util.jar.JarEntry
 import java.util.jar.JarInputStream
 import java.util.stream.Stream
 import javax.annotation.concurrent.ThreadSafe
-import javax.persistence.*
+import javax.persistence.CollectionTable
+import javax.persistence.Column
+import javax.persistence.ElementCollection
+import javax.persistence.Entity
+import javax.persistence.FetchType
+import javax.persistence.ForeignKey
+import javax.persistence.Id
+import javax.persistence.Index
+import javax.persistence.JoinColumn
+import javax.persistence.Lob
+import javax.persistence.Table
 
 /**
  * Stores attachments using Hibernate to database.
@@ -211,7 +236,7 @@ class NodeAttachmentService @JvmOverloads constructor(
         private fun validate() {
             if (counter.count != expectedSize.toLong()) return
 
-            val actual = SecureHash.SHA256(hash.asBytes())
+            val actual = SecureHash.createSHA256(hash.asBytes())
             if (actual != expected)
                 throw HashMismatchException(expected, actual)
         }

serialization-tests/src/test/kotlin/net/corda/serialization/internal/SecureHashSerializationTest.kt

@@ -12,6 +12,7 @@ import org.junit.Assert.assertArrayEquals
 import org.junit.Rule
 import org.junit.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertSame
 import kotlin.test.assertTrue
 
 class SecureHashSerializationTest {
@@ -29,6 +30,7 @@ class SecureHashSerializationTest {
         assertEquals(before.algorithm, after.algorithm)
         assertEquals(after.algorithm, SHA2_256)
         assertTrue(after is SecureHash.SHA256)
+        assertSame(before, after)
     }
 
     @Test(timeout = 300_000)
@@ -41,5 +43,6 @@ class SecureHashSerializationTest {
         assertEquals(before.algorithm, after.algorithm)
         assertEquals(after.algorithm, SHA2_512)
         assertTrue(after is SecureHash.HASH)
+        assertSame(before, after)
     }
 }

serialization/src/main/kotlin/net/corda/serialization/internal/amqp/InterningSerializer.kt

@@ -0,0 +1,24 @@
+package net.corda.serialization.internal.amqp
+
+import net.corda.core.internal.utilities.PrivateInterner
+import net.corda.core.serialization.SerializationContext
+import org.apache.qpid.proton.codec.Data
+import java.lang.reflect.Type
+
+class InterningSerializer(private val delegate: ObjectSerializer, private val interner: PrivateInterner<Any>) : ObjectSerializer by delegate {
+    companion object {
+        fun maybeWrapForInterning(candidate: ObjectSerializer): ObjectSerializer {
+            val clazz = candidate.type as? Class<*>
+            val interner: PrivateInterner<Any>? = PrivateInterner.findFor(clazz)
+            return if (interner != null) InterningSerializer(candidate, interner) else candidate
+        }
+    }
+
+    override fun writeObject(obj: Any, data: Data, type: Type, output: SerializationOutput, context: SerializationContext, debugIndent: Int) {
+        delegate.writeObject(obj, data, type, output, context, debugIndent)
+    }
+
+    override fun readObject(obj: Any, schemas: SerializationSchemas, input: DeserializationInput, context: SerializationContext): Any {
+        return interner.intern(delegate.readObject(obj, schemas, input, context))
+    }
+}

serialization/src/main/kotlin/net/corda/serialization/internal/amqp/ObjectSerializer.kt

@@ -71,7 +71,7 @@ interface ObjectSerializer : AMQPSerializer<Any> {
         private fun makeForComposable(typeInformation: LocalTypeInformation.Composable,
                                       typeNotation: CompositeType,
                                       typeDescriptor: Symbol,
-                                      factory: LocalSerializerFactory): ComposableObjectSerializer {
+                                      factory: LocalSerializerFactory): ObjectSerializer {
             val propertySerializers = makePropertySerializers(typeInformation.properties, factory)
             val reader = ComposableObjectReader(
                     typeInformation.typeIdentifier,
@@ -83,13 +83,13 @@ interface ObjectSerializer : AMQPSerializer<Any> {
                     typeInformation.interfaces,
                     propertySerializers)
 
-            return ComposableObjectSerializer(
+            return InterningSerializer.maybeWrapForInterning(ComposableObjectSerializer(
                     typeInformation.observedType,
                     typeDescriptor,
                     propertySerializers,
                     typeNotation.fields,
                     reader,
-                    writer)
+                    writer))
         }
 
         private fun makePropertySerializers(properties: Map<PropertyName, LocalPropertyInformation>,

serialization/src/test/kotlin/net/corda/serialization/internal/amqp/RoundTripTests.kt

@@ -1,6 +1,7 @@
 package net.corda.serialization.internal.amqp
 
 import net.corda.core.contracts.ContractState
+import net.corda.core.contracts.SignatureAttachmentConstraint
 import net.corda.core.contracts.StateAndRef
 import net.corda.core.contracts.StateRef
 import net.corda.core.contracts.TransactionState
@@ -20,6 +21,8 @@ import org.assertj.core.api.Assertions.assertThatThrownBy
 import org.junit.Test
 import java.math.BigInteger
 import kotlin.test.assertEquals
+import kotlin.test.assertNotSame
+import kotlin.test.assertSame
 
 class RoundTripTests {
 
@@ -145,6 +148,42 @@ class RoundTripTests {
 	fun canSerializeClassesWithUntypedProperties() {
         val data = MembershipState<Any>(mapOf("foo" to "bar"))
         val party = Party(
+                CordaX500Name.interner.intern(CordaX500Name(organisation = "Test Corp", locality = "Madrid", country = "ES")),
+                entropyToKeyPair(BigInteger.valueOf(83)).public)
+        val transactionState = TransactionState(
+                data,
+                "foo",
+                party
+        )
+        val ref = StateRef(SecureHash.zeroHash, 0)
+        val instance = OnMembershipChanged(StateAndRef(
+                transactionState,
+                ref
+        ))
+
+        val factory = testDefaultFactoryNoEvolution().apply { register(PublicKeySerializer) }
+        val bytes = SerializationOutput(factory).serialize(instance)
+        val deserialized = DeserializationInput(factory).deserialize(bytes)
+        assertEquals(mapOf("foo" to "bar"), deserialized.changedMembership.state.data.metadata)
+        assertNotSame(instance.changedMembership.state.notary, deserialized.changedMembership.state.notary)
+        assertSame(instance.changedMembership.state.notary.name, deserialized.changedMembership.state.notary.name)
+        assertSame(instance.changedMembership.state.notary.owningKey, deserialized.changedMembership.state.notary.owningKey)
+    }
+
+    @Test(timeout = 300_000)
+    fun sigConstraintsInterned() {
+        val instance = SignatureAttachmentConstraint.create(entropyToKeyPair(BigInteger.valueOf(83)).public)
+
+        val factory = testDefaultFactoryNoEvolution().apply { register(PublicKeySerializer) }
+        val bytes = SerializationOutput(factory).serialize(instance)
+        val deserialized = DeserializationInput(factory).deserialize(bytes)
+        assertSame(instance, deserialized)
+    }
+
+    @Test(timeout = 300_000)
+    fun canSerializeClassesWithUntypedPropertiesWithInternedParty() {
+        val data = MembershipState<Any>(mapOf("foo" to "bar"))
+        val party = Party.create(
                 CordaX500Name(organisation = "Test Corp", locality = "Madrid", country = "ES"),
                 entropyToKeyPair(BigInteger.valueOf(83)).public)
         val transactionState = TransactionState(
@@ -162,6 +201,7 @@ class RoundTripTests {
         val bytes = SerializationOutput(factory).serialize(instance)
         val deserialized = DeserializationInput(factory).deserialize(bytes)
         assertEquals(mapOf("foo" to "bar"), deserialized.changedMembership.state.data.metadata)
+        assertSame(instance.changedMembership.state.notary, deserialized.changedMembership.state.notary)
     }
 
     interface I2<T> {
@@ -170,8 +210,8 @@ class RoundTripTests {
 
     data class C<A, B : A>(override val t: B) : I2<B>
 
-    @Test(timeout=300_000)
+    @Test(timeout = 300_000)
-	fun recursiveTypeVariableResolution() {
+    fun recursiveTypeVariableResolution() {
         val factory = testDefaultFactoryNoEvolution()
         val instance = C<Collection<String>, List<String>>(emptyList())