core: General tsig (#177)

14 files changed, 287 insertions, 73 deletions

diff --git a/core/configuration-chain.go b/core/configuration-chain.go
index aca1a84..c9dbab9 100644
--- a/core/configuration-chain.go
+++ b/core/configuration-chain.go
@@ -31,6 +31,8 @@ import (
 var (
 	ErrDKGNotRegistered = fmt.Errorf(
 		"not yet registered in DKG protocol")
+	ErrTSigAlreadyRunning = fmt.Errorf(
+		"tsig is already running")
 	ErrDKGNotReady = fmt.Errorf(
 		"DKG is not ready")
 )
@@ -44,10 +46,10 @@ type configurationChain struct {
 	dkgSigner map[uint64]*dkgShareSecret
 	gpk       map[uint64]*DKGGroupPublicKey
 	dkgResult sync.RWMutex
-	tsig      *tsigProtocol
+	tsig      map[common.Hash]*tsigProtocol
 	tsigReady *sync.Cond
 	// TODO(jimmy-dexon): add timeout to pending psig.
-	pendingPsig []*types.DKGPartialSignature
+	pendingPsig map[common.Hash][]*types.DKGPartialSignature
 	prevHash    common.Hash
 }
 
@@ -56,12 +58,14 @@ func newConfigurationChain(
 	recv dkgReceiver,
 	gov Governance) *configurationChain {
 	return &configurationChain{
-		ID:        ID,
-		recv:      recv,
-		gov:       gov,
-		dkgSigner: make(map[uint64]*dkgShareSecret),
-		gpk:       make(map[uint64]*DKGGroupPublicKey),
-		tsigReady: sync.NewCond(&sync.Mutex{}),
+		ID:          ID,
+		recv:        recv,
+		gov:         gov,
+		dkgSigner:   make(map[uint64]*dkgShareSecret),
+		gpk:         make(map[uint64]*DKGGroupPublicKey),
+		tsig:        make(map[common.Hash]*tsigProtocol),
+		tsigReady:   sync.NewCond(&sync.Mutex{}),
+		pendingPsig: make(map[common.Hash][]*types.DKGPartialSignature),
 	}
 }
 
@@ -148,8 +152,7 @@ func (cc *configurationChain) runDKG(round uint64) error {
 }
 
 func (cc *configurationChain) preparePartialSignature(
-	round uint64, hash common.Hash, psigType types.DKGPartialSignatureType) (
-	*types.DKGPartialSignature, error) {
+	round uint64, hash common.Hash) (*types.DKGPartialSignature, error) {
 	signer, exist := func() (*dkgShareSecret, bool) {
 		cc.dkgResult.RLock()
 		defer cc.dkgResult.RUnlock()
@@ -162,13 +165,13 @@ func (cc *configurationChain) preparePartialSignature(
 	return &types.DKGPartialSignature{
 		ProposerID:       cc.ID,
 		Round:            round,
-		Type:             psigType,
+		Hash:             hash,
 		PartialSignature: signer.sign(hash),
 	}, nil
 }
 
 func (cc *configurationChain) runTSig(
-	round uint64, hash common.Hash, psigType types.DKGPartialSignatureType) (
+	round uint64, hash common.Hash) (
 	crypto.Signature, error) {
 	gpk, exist := func() (*DKGGroupPublicKey, bool) {
 		cc.dkgResult.RLock()
@@ -181,12 +184,12 @@ func (cc *configurationChain) runTSig(
 	}
 	cc.tsigReady.L.Lock()
 	defer cc.tsigReady.L.Unlock()
-	for cc.tsig != nil {
-		cc.tsigReady.Wait()
+	if _, exist := cc.tsig[hash]; exist {
+		return crypto.Signature{}, ErrTSigAlreadyRunning
 	}
-	cc.tsig = newTSigProtocol(gpk, hash, psigType)
-	pendingPsig := cc.pendingPsig
-	cc.pendingPsig = []*types.DKGPartialSignature{}
+	cc.tsig[hash] = newTSigProtocol(gpk, hash)
+	pendingPsig := cc.pendingPsig[hash]
+	delete(cc.pendingPsig, hash)
 	go func() {
 		for _, psig := range pendingPsig {
 			if err := cc.processPartialSignature(psig); err != nil {
@@ -197,13 +200,12 @@ func (cc *configurationChain) runTSig(
 	var signature crypto.Signature
 	var err error
 	for func() bool {
-		signature, err = cc.tsig.signature()
+		signature, err = cc.tsig[hash].signature()
 		return err == ErrNotEnoughtPartialSignatures
 	}() {
 		cc.tsigReady.Wait()
 	}
-	cc.tsig = nil
-	cc.tsigReady.Broadcast()
+	delete(cc.tsig, hash)
 	if err != nil {
 		return crypto.Signature{}, err
 	}
@@ -212,7 +214,7 @@ func (cc *configurationChain) runTSig(
 
 func (cc *configurationChain) runBlockTSig(
 	round uint64, hash common.Hash) (crypto.Signature, error) {
-	sig, err := cc.runTSig(round, hash, types.TSigConfigurationBlock)
+	sig, err := cc.runTSig(round, hash)
 	if err != nil {
 		return crypto.Signature{}, err
 	}
@@ -222,7 +224,7 @@ func (cc *configurationChain) runBlockTSig(
 
 func (cc *configurationChain) runCRSTSig(
 	round uint64, crs common.Hash) ([]byte, error) {
-	sig, err := cc.runTSig(round, crs, types.TSigCRS)
+	sig, err := cc.runTSig(round, crs)
 	log.Printf("[%s] CRS(%d): %s\n", cc.ID, round+1, sig)
 	return sig.Signature[:], err
 }
@@ -241,7 +243,7 @@ func (cc *configurationChain) processPartialSignature(
 	psig *types.DKGPartialSignature) error {
 	cc.tsigReady.L.Lock()
 	defer cc.tsigReady.L.Unlock()
-	if cc.tsig == nil || psig.Type != cc.tsig.psigType {
+	if _, exist := cc.tsig[psig.Hash]; !exist {
 		ok, err := verifyDKGPartialSignatureSignature(psig)
 		if err != nil {
 			return err
@@ -249,10 +251,10 @@ func (cc *configurationChain) processPartialSignature(
 		if !ok {
 			return ErrIncorrectPartialSignatureSignature
 		}
-		cc.pendingPsig = append(cc.pendingPsig, psig)
+		cc.pendingPsig[psig.Hash] = append(cc.pendingPsig[psig.Hash], psig)
 		return nil
 	}
-	if err := cc.tsig.processPartialSignature(psig); err != nil {
+	if err := cc.tsig[psig.Hash].processPartialSignature(psig); err != nil {
 		return err
 	}
 	cc.tsigReady.Broadcast()
diff --git a/core/configuration-chain_test.go b/core/configuration-chain_test.go
index 7ebc502..45120b4 100644
--- a/core/configuration-chain_test.go
+++ b/core/configuration-chain_test.go
@@ -25,6 +25,7 @@ import (
 
 	"github.com/stretchr/testify/suite"
 
+	"github.com/dexon-foundation/dexon-consensus-core/common"
 	"github.com/dexon-foundation/dexon-consensus-core/core/crypto"
 	"github.com/dexon-foundation/dexon-consensus-core/core/crypto/dkg"
 	"github.com/dexon-foundation/dexon-consensus-core/core/crypto/ecdsa"
@@ -141,14 +142,8 @@ func (s *ConfigurationChainTestSuite) setupNodes(n int) {
 	}
 }
 
-// TestConfigurationChain will test the entire DKG+TISG protocol including
-// exchanging private shares, recovering share secret, creating partial sign and
-// recovering threshold signature.
-// All participants are good people in this test.
-func (s *ConfigurationChainTestSuite) TestConfigurationChain() {
-	k := 3
-	n := 10
-	round := uint64(1)
+func (s *ConfigurationChainTestSuite) runDKG(
+	k, n int, round uint64) map[types.NodeID]*configurationChain {
 	s.setupNodes(n)
 
 	cfgChains := make(map[types.NodeID]*configurationChain)
@@ -183,14 +178,20 @@ func (s *ConfigurationChainTestSuite) TestConfigurationChain() {
 	for range cfgChains {
 		s.Require().NoError(<-errs)
 	}
+	return cfgChains
+}
 
-	psigs := make([]*types.DKGPartialSignature, 0, n)
-	hash := crypto.Keccak256Hash([]byte("🌚🌝"))
+func (s *ConfigurationChainTestSuite) preparePartialSignature(
+	hash common.Hash,
+	round uint64,
+	cfgChains map[types.NodeID]*configurationChain) (
+	psigs []*types.DKGPartialSignature) {
+	psigs = make([]*types.DKGPartialSignature, 0, len(cfgChains))
 	for nID, cc := range cfgChains {
 		if _, exist := cc.gpk[round].qualifyNodeIDs[nID]; !exist {
 			continue
 		}
-		psig, err := cc.preparePartialSignature(round, hash, types.TSigCRS)
+		psig, err := cc.preparePartialSignature(round, hash)
 		s.Require().NoError(err)
 		prvKey, exist := s.prvKeys[cc.ID]
 		s.Require().True(exist)
@@ -198,16 +199,31 @@ func (s *ConfigurationChainTestSuite) TestConfigurationChain() {
 		s.Require().NoError(err)
 		psigs = append(psigs, psig)
 	}
+	return
+}
+
+// TestConfigurationChain will test the entire DKG+TISG protocol including
+// exchanging private shares, recovering share secret, creating partial sign and
+// recovering threshold signature.
+// All participants are good people in this test.
+func (s *ConfigurationChainTestSuite) TestConfigurationChain() {
+	k := 3
+	n := 10
+	round := uint64(1)
+	cfgChains := s.runDKG(k, n, round)
+
+	hash := crypto.Keccak256Hash([]byte("🌚🌝"))
+	psigs := s.preparePartialSignature(hash, round, cfgChains)
 
 	tsigs := make([]crypto.Signature, 0, n)
-	errs = make(chan error, n)
+	errs := make(chan error, n)
 	tsigChan := make(chan crypto.Signature, n)
 	for nID, cc := range cfgChains {
 		if _, exist := cc.gpk[round].qualifyNodeIDs[nID]; !exist {
 			continue
 		}
 		go func(cc *configurationChain) {
-			tsig, err := cc.runTSig(round, hash, types.TSigCRS)
+			tsig, err := cc.runTSig(round, hash)
 			// Prevent racing by collecting errors and check in main thread.
 			errs <- err
 			tsigChan <- tsig
@@ -229,6 +245,66 @@ func (s *ConfigurationChainTestSuite) TestConfigurationChain() {
 	}
 }
 
+func (s *ConfigurationChainTestSuite) TestMultipleTSig() {
+	k := 2
+	n := 7
+	round := uint64(1)
+	cfgChains := s.runDKG(k, n, round)
+
+	hash1 := crypto.Keccak256Hash([]byte("Hash1"))
+	hash2 := crypto.Keccak256Hash([]byte("Hash2"))
+
+	psigs1 := s.preparePartialSignature(hash1, round, cfgChains)
+	psigs2 := s.preparePartialSignature(hash2, round, cfgChains)
+
+	tsigs1 := make([]crypto.Signature, 0, n)
+	tsigs2 := make([]crypto.Signature, 0, n)
+
+	errs := make(chan error, n*2)
+	tsigChan1 := make(chan crypto.Signature, n)
+	tsigChan2 := make(chan crypto.Signature, n)
+	for nID, cc := range cfgChains {
+		if _, exist := cc.gpk[round].qualifyNodeIDs[nID]; !exist {
+			continue
+		}
+		go func(cc *configurationChain) {
+			tsig1, err := cc.runTSig(round, hash1)
+			// Prevent racing by collecting errors and check in main thread.
+			errs <- err
+			tsigChan1 <- tsig1
+		}(cc)
+		go func(cc *configurationChain) {
+			tsig2, err := cc.runTSig(round, hash2)
+			// Prevent racing by collecting errors and check in main thread.
+			errs <- err
+			tsigChan2 <- tsig2
+		}(cc)
+		for _, psig := range psigs1 {
+			err := cc.processPartialSignature(psig)
+			s.Require().NoError(err)
+		}
+		for _, psig := range psigs2 {
+			err := cc.processPartialSignature(psig)
+			s.Require().NoError(err)
+		}
+	}
+	for nID, cc := range cfgChains {
+		if _, exist := cc.gpk[round].qualifyNodeIDs[nID]; !exist {
+			continue
+		}
+		s.Require().NoError(<-errs)
+		tsig1 := <-tsigChan1
+		for _, prevTsig := range tsigs1 {
+			s.Equal(prevTsig, tsig1)
+		}
+		s.Require().NoError(<-errs)
+		tsig2 := <-tsigChan2
+		for _, prevTsig := range tsigs2 {
+			s.Equal(prevTsig, tsig2)
+		}
+	}
+}
+
 func TestConfigurationChain(t *testing.T) {
 	suite.Run(t, new(ConfigurationChainTestSuite))
 }
diff --git a/core/consensus.go b/core/consensus.go
index b1615a2..c53d151 100644
--- a/core/consensus.go
+++ b/core/consensus.go
@@ -44,6 +44,12 @@ var (
 		"unknown block is proposed")
 	ErrUnknownBlockConfirmed = fmt.Errorf(
 		"unknown block is confirmed")
+	ErrIncorrectAgreementResultPosition = fmt.Errorf(
+		"incorrect agreement result position")
+	ErrNotEnoughVotes = fmt.Errorf(
+		"not enought votes")
+	ErrIncorrectVoteProposer = fmt.Errorf(
+		"incorrect vote proposer")
 )
 
 // consensusBAReceiver implements agreementReceiver.
@@ -385,7 +391,7 @@ func (con *Consensus) runDKGTSIG() {
 			common.Hash{},
 			con.cfgModule.prevHash)
 		psig, err := con.cfgModule.preparePartialSignature(
-			round, hash, types.TSigConfigurationBlock)
+			round, hash)
 		if err != nil {
 			panic(err)
 		}
@@ -405,7 +411,7 @@ func (con *Consensus) runDKGTSIG() {
 func (con *Consensus) runCRS() {
 	// Start running next round CRS.
 	psig, err := con.cfgModule.preparePartialSignature(
-		con.round, con.gov.CRS(con.round), types.TSigCRS)
+		con.round, con.gov.CRS(con.round))
 	if err != nil {
 		log.Println(err)
 	} else if err = con.authModule.SignDKGPartialSignature(psig); err != nil {
@@ -471,6 +477,14 @@ func (con *Consensus) processMsg(msgChan <-chan interface{}) {
 			if err := con.ProcessVote(val); err != nil {
 				log.Println(err)
 			}
+		case *types.AgreementResult:
+			if err := con.ProcessAgreementResult(val); err != nil {
+				log.Println(err)
+			}
+		case *types.BlockRandomnessResult:
+			if err := con.ProcessBlockRandomnessResult(val); err != nil {
+				log.Println(err)
+			}
 		case *types.DKGPrivateShare:
 			if err := con.cfgModule.processPrivateShare(val); err != nil {
 				log.Println(err)
@@ -504,6 +518,51 @@ func (con *Consensus) ProcessVote(vote *types.Vote) (err error) {
 	return err
 }
 
+// ProcessAgreementResult processes the randomness request.
+func (con *Consensus) ProcessAgreementResult(
+	rand *types.AgreementResult) error {
+	if con.round != rand.Round {
+		return nil
+	}
+	dkgSet, err := con.nodeSetCache.GetDKGSet(rand.Round)
+	if err != nil {
+		return err
+	}
+	if _, exist := dkgSet[con.ID]; !exist {
+		return nil
+	}
+	if len(rand.Votes) <= con.currentConfig.NumNotarySet/3*2 {
+		return ErrNotEnoughVotes
+	}
+	if rand.Position.ChainID >= con.currentConfig.NumChains {
+		return ErrIncorrectAgreementResultPosition
+	}
+	notarySet, err := con.nodeSetCache.GetNotarySet(
+		rand.Round, rand.Position.ChainID)
+	if err != nil {
+		return err
+	}
+	for _, vote := range rand.Votes {
+		if _, exist := notarySet[vote.ProposerID]; !exist {
+			return ErrIncorrectVoteProposer
+		}
+		ok, err := verifyVoteSignature(&vote)
+		if err != nil {
+			return nil
+		}
+		if !ok {
+			return ErrIncorrectVoteSignature
+		}
+	}
+	return nil
+}
+
+// ProcessBlockRandomnessResult processes the randomness result.
+func (con *Consensus) ProcessBlockRandomnessResult(
+	rand *types.BlockRandomnessResult) error {
+	return nil
+}
+
 // preProcessBlock performs Byzantine Agreement on the block.
 func (con *Consensus) preProcessBlock(b *types.Block) (err error) {
 	if err = con.lattice.SanityCheck(b); err != nil {
diff --git a/core/consensus_test.go b/core/consensus_test.go
index e8615a2..6827352 100644
--- a/core/consensus_test.go
+++ b/core/consensus_test.go
@@ -47,6 +47,18 @@ func (n *network) BroadcastBlock(block *types.Block) {
 	n.conn.broadcast(n.nID, block)
 }
 
+// BroadcastRandomnessRequest broadcasts rand request to DKG set.
+func (n *network) BroadcastRandomnessRequest(
+	randRequest *types.AgreementResult) {
+	n.conn.broadcast(n.nID, randRequest)
+}
+
+// BroadcastRandomnessResult broadcasts rand request to Notary set.
+func (n *network) BroadcastRandomnessResult(
+	randResult *types.BlockRandomnessResult) {
+	n.conn.broadcast(n.nID, randResult)
+}
+
 // SendDKGPrivateShare sends PrivateShare to a DKG participant.
 func (n *network) SendDKGPrivateShare(
 	recv crypto.PublicKey, prvShare *types.DKGPrivateShare) {
diff --git a/core/crypto.go b/core/crypto.go
index 6fc0d1b..bc6463f 100644
--- a/core/crypto.go
+++ b/core/crypto.go
@@ -217,13 +217,10 @@ func hashDKGPartialSignature(psig *types.DKGPartialSignature) common.Hash {
 	binaryRound := make([]byte, 8)
 	binary.LittleEndian.PutUint64(binaryRound, psig.Round)
 
-	binaryType := make([]byte, 4)
-	binary.LittleEndian.PutUint32(binaryType, uint32(psig.Type))
-
 	return crypto.Keccak256Hash(
 		psig.ProposerID.Hash[:],
 		binaryRound,
-		binaryType,
+		psig.Hash[:],
 		psig.PartialSignature.Signature[:],
 	)
 }
diff --git a/core/dkg-tsig-protocol.go b/core/dkg-tsig-protocol.go
index 9c0c476..3853468 100644
--- a/core/dkg-tsig-protocol.go
+++ b/core/dkg-tsig-protocol.go
@@ -38,8 +38,8 @@ var (
 		"threshold not reach")
 	ErrIncorrectPrivateShareSignature = fmt.Errorf(
 		"incorrect private share signature")
-	ErrMismatchPartialSignatureType = fmt.Errorf(
-		"mismatch partialSignature type")
+	ErrMismatchPartialSignatureHash = fmt.Errorf(
+		"mismatch partialSignature hash")
 	ErrIncorrectPartialSignatureSignature = fmt.Errorf(
 		"incorrect partialSignature signature")
 	ErrIncorrectPartialSignature = fmt.Errorf(
@@ -95,7 +95,6 @@ type DKGGroupPublicKey struct {
 type tsigProtocol struct {
 	groupPublicKey *DKGGroupPublicKey
 	hash           common.Hash
-	psigType       types.DKGPartialSignatureType
 	sigs           map[dkg.ID]dkg.PartialSignature
 	threshold      int
 }
@@ -398,12 +397,10 @@ func (gpk *DKGGroupPublicKey) VerifySignature(
 
 func newTSigProtocol(
 	gpk *DKGGroupPublicKey,
-	hash common.Hash,
-	psigType types.DKGPartialSignatureType) *tsigProtocol {
+	hash common.Hash) *tsigProtocol {
 	return &tsigProtocol{
 		groupPublicKey: gpk,
 		hash:           hash,
-		psigType:       psigType,
 		sigs:           make(map[dkg.ID]dkg.PartialSignature, gpk.threshold+1),
 	}
 }
@@ -420,8 +417,8 @@ func (tsig *tsigProtocol) sanityCheck(psig *types.DKGPartialSignature) error {
 	if !ok {
 		return ErrIncorrectPartialSignatureSignature
 	}
-	if psig.Type != tsig.psigType {
-		return ErrMismatchPartialSignatureType
+	if psig.Hash != tsig.hash {
+		return ErrMismatchPartialSignatureHash
 	}
 	return nil
 }
diff --git a/core/dkg-tsig-protocol_test.go b/core/dkg-tsig-protocol_test.go
index 9743531..a3a0acc 100644
--- a/core/dkg-tsig-protocol_test.go
+++ b/core/dkg-tsig-protocol_test.go
@@ -211,12 +211,12 @@ func (s *DKGTSIGProtocolTestSuite) TestDKGTSIGProtocol() {
 	}
 
 	msgHash := crypto.Keccak256Hash([]byte("🏖🍹"))
-	tsig := newTSigProtocol(gpk, msgHash, types.TSigConfigurationBlock)
+	tsig := newTSigProtocol(gpk, msgHash)
 	for nID, shareSecret := range shareSecrets {
 		psig := &types.DKGPartialSignature{
 			ProposerID:       nID,
 			Round:            round,
-			Type:             types.TSigConfigurationBlock,
+			Hash:             msgHash,
 			PartialSignature: shareSecret.sign(msgHash),
 		}
 		var err error
@@ -578,14 +578,14 @@ func (s *DKGTSIGProtocolTestSuite) TestPartialSignature() {
 	}
 
 	msgHash := crypto.Keccak256Hash([]byte("🏖🍹"))
-	tsig := newTSigProtocol(gpk, msgHash, types.TSigConfigurationBlock)
+	tsig := newTSigProtocol(gpk, msgHash)
 	byzantineID2 := s.nIDs[1]
 	byzantineID3 := s.nIDs[2]
 	for nID, shareSecret := range shareSecrets {
 		psig := &types.DKGPartialSignature{
 			ProposerID:       nID,
 			Round:            round,
-			Type:             types.TSigConfigurationBlock,
+			Hash:             msgHash,
 			PartialSignature: shareSecret.sign(msgHash),
 		}
 		switch nID {
@@ -593,7 +593,7 @@ func (s *DKGTSIGProtocolTestSuite) TestPartialSignature() {
 			psig.PartialSignature = shareSecret.sign(
 				crypto.Keccak256Hash([]byte("💣")))
 		case byzantineID3:
-			psig.Type = types.TSigNotaryAck
+			psig.Hash = common.NewRandomHash()
 		}
 		var err error
 		psig.Signature, err = s.prvKeys[nID].Sign(hashDKGPartialSignature(psig))
@@ -605,7 +605,7 @@ func (s *DKGTSIGProtocolTestSuite) TestPartialSignature() {
 		case byzantineID2:
 			s.Require().Equal(ErrIncorrectPartialSignature, err)
 		case byzantineID3:
-			s.Require().Equal(ErrMismatchPartialSignatureType, err)
+			s.Require().Equal(ErrMismatchPartialSignatureHash, err)
 		default:
 			s.Require().NoError(err)
 		}
diff --git a/core/interfaces.go b/core/interfaces.go
index c367933..710550f 100644
--- a/core/interfaces.go
+++ b/core/interfaces.go
@@ -64,6 +64,12 @@ type Network interface {
 	// BroadcastBlock broadcasts block to all nodes in DEXON network.
 	BroadcastBlock(block *types.Block)
 
+	// BroadcastRandomnessRequest broadcasts rand request to DKG set.
+	BroadcastRandomnessRequest(randRequest *types.AgreementResult)
+
+	// BroadcastRandomnessResult broadcasts rand request to Notary set.
+	BroadcastRandomnessResult(randResult *types.BlockRandomnessResult)
+
 	// SendDKGPrivateShare sends PrivateShare to a DKG participant.
 	SendDKGPrivateShare(pub crypto.PublicKey, prvShare *types.DKGPrivateShare)
 
diff --git a/core/types/block-randomness.go b/core/types/block-randomness.go
new file mode 100644
index 0000000..896904a
--- /dev/null
+++ b/core/types/block-randomness.go
@@ -0,0 +1,37 @@
+// Copyright 2018 The dexon-consensus-core Authors
+// This file is part of the dexon-consensus-core library.
+//
+// The dexon-consensus-core library is free software: you can redistribute it
+// and/or modify it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation, either version 3 of the License,
+// or (at your option) any later version.
+//
+// The dexon-consensus-core library is distributed in the hope that it will be
+// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+// General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the dexon-consensus-core library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+package types
+
+import (
+	"github.com/dexon-foundation/dexon-consensus-core/common"
+)
+
+// AgreementResult describes an agremeent result.
+type AgreementResult struct {
+	BlockHash common.Hash `json:"block_hash"`
+	Round     uint64      `json:"round"`
+	Position  Position    `json:"position"`
+	Votes     []Vote      `json:"votes"`
+}
+
+// BlockRandomnessResult describes a block randomness result
+type BlockRandomnessResult struct {
+	BlockHash  common.Hash `json:"block_hash"`
+	Round      uint64      `json:"round"`
+	Randomness []byte      `json:"randomness"`
+}
diff --git a/core/types/block.go b/core/types/block.go
index 297f479..fc69481 100644
--- a/core/types/block.go
+++ b/core/types/block.go
@@ -68,6 +68,7 @@ type Block struct {
 	Timestamp          time.Time           `json:"timestamps"`
 	Acks               common.SortedHashes `json:"acks"`
 	Payload            []byte              `json:"payload"`
+	Randomness         []byte              `json:"randomness"`
 	ConsensusTimestamp time.Time           `json:"consensus_timestamp"`
 	ConsensusHeight    uint64              `json:"consensus_height"`
 	Witness            Witness             `json:"witness"`
@@ -102,6 +103,8 @@ func (b *Block) Clone() (bcopy *Block) {
 	copy(bcopy.Acks, b.Acks)
 	bcopy.Payload = make([]byte, len(b.Payload))
 	copy(bcopy.Payload, b.Payload)
+	bcopy.Randomness = make([]byte, len(b.Randomness))
+	copy(bcopy.Randomness, b.Randomness)
 	return
 }
 
diff --git a/core/types/block_test.go b/core/types/block_test.go
index 3e601b6..07d27ab 100644
--- a/core/types/block_test.go
+++ b/core/types/block_test.go
@@ -60,6 +60,7 @@ func (s *BlockTestSuite) createRandomBlock() *Block {
 		ConsensusHeight:    rand.Uint64(),
 		ConsensusTimestamp: time.Now().Add(time.Duration(rand.Int())),
 		Payload:            s.randomBytes(),
+		Randomness:         s.randomBytes(),
 		Signature:          crypto.Signature{Signature: s.randomBytes()},
 		CRSSignature:       crypto.Signature{Signature: s.randomBytes()},
 	}
diff --git a/core/types/dkg.go b/core/types/dkg.go
index df9d8e3..a4c6bf1 100644
--- a/core/types/dkg.go
+++ b/core/types/dkg.go
@@ -20,6 +20,7 @@ package types
 import (
 	"fmt"
 
+	"github.com/dexon-foundation/dexon-consensus-core/common"
 	"github.com/dexon-foundation/dexon-consensus-core/core/crypto"
 	"github.com/dexon-foundation/dexon-consensus-core/core/crypto/dkg"
 )
@@ -66,23 +67,13 @@ type DKGComplaint struct {
 	Signature    crypto.Signature `json:"signature"`
 }
 
-// DKGPartialSignatureType specifies ths threshold signature type.
-type DKGPartialSignatureType uint32
-
-// TSig enums.
-const (
-	TSigConfigurationBlock DKGPartialSignatureType = iota
-	TSigNotaryAck
-	TSigCRS
-)
-
 // DKGPartialSignature describe a partial signature in DKG protocol.
 type DKGPartialSignature struct {
-	ProposerID       NodeID                  `json:"proposerID"`
-	Round            uint64                  `json:"round"`
-	Type             DKGPartialSignatureType `json:"type"`
-	PartialSignature dkg.PartialSignature    `json:"partial_signature"`
-	Signature        crypto.Signature        `json:"signature"`
+	ProposerID       NodeID               `json:"proposerID"`
+	Round            uint64               `json:"round"`
+	Hash             common.Hash          `json:"hash"`
+	PartialSignature dkg.PartialSignature `json:"partial_signature"`
+	Signature        crypto.Signature     `json:"signature"`
 }
 
 // IsNack returns true if it's a nack complaint in DKG protocol.
diff --git a/simulation/marshaller.go b/simulation/marshaller.go
index cdf080b..d677c1f 100644
--- a/simulation/marshaller.go
+++ b/simulation/marshaller.go
@@ -63,6 +63,18 @@ func (m *jsonMarshaller) Unmarshal(
 			break
 		}
 		msg = vote
+	case "block-randomness-request":
+		request := &types.AgreementResult{}
+		if err = json.Unmarshal(payload, request); err != nil {
+			break
+		}
+		msg = request
+	case "block-randomness-result":
+		result := &types.BlockRandomnessResult{}
+		if err = json.Unmarshal(payload, result); err != nil {
+			break
+		}
+		msg = result
 	case "dkg-private-share":
 		privateShare := &types.DKGPrivateShare{}
 		if err = json.Unmarshal(payload, privateShare); err != nil {
@@ -111,6 +123,10 @@ func (m *jsonMarshaller) Marshal(msg interface{}) (
 		msgType = "block"
 	case *types.Vote:
 		msgType = "vote"
+	case *types.AgreementResult:
+		msgType = "block-randomness-request"
+	case *types.BlockRandomnessResult:
+		msgType = "block-randomness-result"
 	case *types.DKGPrivateShare:
 		msgType = "dkg-private-share"
 	case *types.DKGMasterPublicKey:
diff --git a/simulation/network.go b/simulation/network.go
index 0faacf7..ab3b4fa 100644
--- a/simulation/network.go
+++ b/simulation/network.go
@@ -132,6 +132,22 @@ func (n *network) BroadcastBlock(block *types.Block) {
 	}
 }
 
+// BroadcastRandomnessRequest implements core.Network interface.
+func (n *network) BroadcastRandomnessRequest(
+	randRequest *types.AgreementResult) {
+	if err := n.trans.Broadcast(randRequest); err != nil {
+		panic(err)
+	}
+}
+
+// BroadcastRandomnessResult implements core.Network interface.
+func (n *network) BroadcastRandomnessResult(
+	randResult *types.BlockRandomnessResult) {
+	if err := n.trans.Broadcast(randResult); err != nil {
+		panic(err)
+	}
+}
+
 // broadcast message to all other nodes in the network.
 func (n *network) broadcast(message interface{}) {
 	if err := n.trans.Broadcast(message); err != nil {
@@ -199,6 +215,7 @@ func (n *network) run() {
 	disp := func(e *test.TransportEnvelope) {
 		switch e.Msg.(type) {
 		case *types.Block, *types.Vote,
+			*types.AgreementResult, *types.BlockRandomnessResult,
 			*types.DKGPrivateShare, *types.DKGPartialSignature:
 			n.toConsensus <- e.Msg
 		default: