vendor: sync to latest core (#91)

- Implement new methods in db to cache DKG
   private key.
- Implement new methods in db to cache compaction
   chain tip.

9 files changed, 404 insertions, 101 deletions

diff --git a/vendor/github.com/dexon-foundation/dexon-consensus/core/configuration-chain.go b/vendor/github.com/dexon-foundation/dexon-consensus/core/configuration-chain.go
index 364f2c75c..2b3a859ed 100644
--- a/vendor/github.com/dexon-foundation/dexon-consensus/core/configuration-chain.go
+++ b/vendor/github.com/dexon-foundation/dexon-consensus/core/configuration-chain.go
@@ -24,6 +24,7 @@ import (
 
 	"github.com/dexon-foundation/dexon-consensus/common"
 	"github.com/dexon-foundation/dexon-consensus/core/crypto"
+	"github.com/dexon-foundation/dexon-consensus/core/db"
 	"github.com/dexon-foundation/dexon-consensus/core/types"
 	typesDKG "github.com/dexon-foundation/dexon-consensus/core/types/dkg"
 	"github.com/dexon-foundation/dexon-consensus/core/utils"
@@ -53,6 +54,7 @@ type configurationChain struct {
 	tsigTouched     map[common.Hash]struct{}
 	tsigReady       *sync.Cond
 	cache           *utils.NodeSetCache
+	db              db.Database
 	dkgSet          map[types.NodeID]struct{}
 	mpkReady        bool
 	pendingPrvShare map[types.NodeID]*typesDKG.PrivateShare
@@ -66,6 +68,7 @@ func newConfigurationChain(
 	recv dkgReceiver,
 	gov Governance,
 	cache *utils.NodeSetCache,
+	dbInst db.Database,
 	logger common.Logger) *configurationChain {
 	return &configurationChain{
 		ID:          ID,
@@ -78,6 +81,7 @@ func newConfigurationChain(
 		tsigTouched: make(map[common.Hash]struct{}),
 		tsigReady:   sync.NewCond(&sync.Mutex{}),
 		cache:       cache,
+		db:          dbInst,
 		pendingPsig: make(map[common.Hash][]*typesDKG.PartialSignature),
 	}
 }
@@ -104,6 +108,10 @@ func (cc *configurationChain) registerDKG(round uint64, threshold int) {
 }
 
 func (cc *configurationChain) runDKG(round uint64) error {
+	// Check if corresponding DKG signer is ready.
+	if _, _, err := cc.getDKGInfo(round); err == nil {
+		return nil
+	}
 	cc.dkgLock.Lock()
 	defer cc.dkgLock.Unlock()
 	if cc.dkg == nil || cc.dkg.round != round {
@@ -113,20 +121,11 @@ func (cc *configurationChain) runDKG(round uint64) error {
 		}
 		return ErrDKGNotRegistered
 	}
-	if func() bool {
-		cc.dkgResult.RLock()
-		defer cc.dkgResult.RUnlock()
-		_, exist := cc.gpk[round]
-		return exist
-	}() {
-		return nil
-	}
 	cc.logger.Debug("Calling Governance.IsDKGFinal", "round", round)
 	if cc.gov.IsDKGFinal(round) {
 		cc.logger.Warn("DKG already final", "round", round)
 		return nil
 	}
-
 	ticker := newTicker(cc.gov, round, TickerDKG)
 	cc.dkgLock.Unlock()
 	<-ticker.Tick()
@@ -153,7 +152,8 @@ func (cc *configurationChain) runDKG(round uint64) error {
 	cc.dkgLock.Lock()
 	// Phase 5(T = 2λ): Propose Anti nack complaint.
 	cc.logger.Debug("Calling Governance.DKGComplaints", "round", round)
-	cc.dkg.processNackComplaints(cc.gov.DKGComplaints(round))
+	complaints := cc.gov.DKGComplaints(round)
+	cc.dkg.processNackComplaints(complaints)
 	cc.dkgLock.Unlock()
 	<-ticker.Tick()
 	cc.dkgLock.Lock()
@@ -163,8 +163,7 @@ func (cc *configurationChain) runDKG(round uint64) error {
 	<-ticker.Tick()
 	cc.dkgLock.Lock()
 	// Phase 7(T = 4λ): Enforce complaints and nack complaints.
-	cc.logger.Debug("Calling Governance.DKGComplaints", "round", round)
-	cc.dkg.enforceNackComplaints(cc.gov.DKGComplaints(round))
+	cc.dkg.enforceNackComplaints(complaints)
 	// Enforce complaint is done in `processPrivateShare`.
 	// Phase 8(T = 5λ): DKG finalize.
 	cc.dkgLock.Unlock()
@@ -209,6 +208,10 @@ func (cc *configurationChain) runDKG(round uint64) error {
 	if err != nil {
 		return err
 	}
+	// Save private shares to DB.
+	if err = cc.db.PutDKGPrivateKey(round, *signer.privateKey); err != nil {
+		return err
+	}
 	cc.dkgResult.Lock()
 	defer cc.dkgResult.Unlock()
 	cc.dkgSigner[round] = signer
@@ -220,23 +223,74 @@ func (cc *configurationChain) isDKGReady(round uint64) bool {
 	if !cc.gov.IsDKGFinal(round) {
 		return false
 	}
-	return func() bool {
+	_, _, err := cc.getDKGInfo(round)
+	return err == nil
+}
+
+func (cc *configurationChain) getDKGInfo(
+	round uint64) (*DKGGroupPublicKey, *dkgShareSecret, error) {
+	getFromCache := func() (*DKGGroupPublicKey, *dkgShareSecret) {
 		cc.dkgResult.RLock()
 		defer cc.dkgResult.RUnlock()
-		_, exist := cc.gpk[round]
-		return exist
-	}()
+		gpk := cc.gpk[round]
+		signer := cc.dkgSigner[round]
+		return gpk, signer
+	}
+	gpk, signer := getFromCache()
+	if gpk == nil || signer == nil {
+		if err := cc.recoverDKGInfo(round); err != nil {
+			return nil, nil, err
+		}
+		gpk, signer = getFromCache()
+	}
+	if gpk == nil || signer == nil {
+		return nil, nil, ErrDKGNotReady
+	}
+	return gpk, signer, nil
+}
+
+func (cc *configurationChain) recoverDKGInfo(round uint64) error {
+	cc.dkgResult.Lock()
+	defer cc.dkgResult.Unlock()
+	_, signerExists := cc.dkgSigner[round]
+	_, gpkExists := cc.gpk[round]
+	if signerExists && gpkExists {
+		return nil
+	}
+	if !cc.gov.IsDKGFinal(round) {
+		return ErrDKGNotReady
+	}
+
+	threshold := getDKGThreshold(cc.gov.Configuration(round))
+	// Restore group public key.
+	gpk, err := NewDKGGroupPublicKey(round,
+		cc.gov.DKGMasterPublicKeys(round),
+		cc.gov.DKGComplaints(round),
+		threshold)
+	if err != nil {
+		return err
+	}
+	// Restore DKG share secret, this segment of code is copied from
+	// dkgProtocol.recoverShareSecret.
+	if len(gpk.qualifyIDs) < threshold {
+		return ErrNotReachThreshold
+	}
+	// Check if we have private shares in DB.
+	prvKey, err := cc.db.GetDKGPrivateKey(round)
+	if err != nil {
+		return err
+	}
+	cc.gpk[round] = gpk
+	cc.dkgSigner[round] = &dkgShareSecret{
+		privateKey: &prvKey,
+	}
+	return nil
 }
 
 func (cc *configurationChain) preparePartialSignature(
 	round uint64, hash common.Hash) (*typesDKG.PartialSignature, error) {
-	signer, exist := func() (*dkgShareSecret, bool) {
-		cc.dkgResult.RLock()
-		defer cc.dkgResult.RUnlock()
-		signer, exist := cc.dkgSigner[round]
-		return signer, exist
-	}()
-	if !exist {
+	_, signer, _ := cc.getDKGInfo(round)
+	if signer == nil {
 		return nil, ErrDKGNotReady
 	}
 	return &typesDKG.PartialSignature{
@@ -264,13 +318,8 @@ func (cc *configurationChain) untouchTSigHash(hash common.Hash) {
 func (cc *configurationChain) runTSig(
 	round uint64, hash common.Hash) (
 	crypto.Signature, error) {
-	gpk, exist := func() (*DKGGroupPublicKey, bool) {
-		cc.dkgResult.RLock()
-		defer cc.dkgResult.RUnlock()
-		gpk, exist := cc.gpk[round]
-		return gpk, exist
-	}()
-	if !exist {
+	gpk, _, _ := cc.getDKGInfo(round)
+	if gpk == nil {
 		return crypto.Signature{}, ErrDKGNotReady
 	}
 	cc.tsigReady.L.Lock()
diff --git a/vendor/github.com/dexon-foundation/dexon-consensus/core/consensus.go b/vendor/github.com/dexon-foundation/dexon-consensus/core/consensus.go
index a6d80371d..5beaf546a 100644
--- a/vendor/github.com/dexon-foundation/dexon-consensus/core/consensus.go
+++ b/vendor/github.com/dexon-foundation/dexon-consensus/core/consensus.go
@@ -424,6 +424,7 @@ func NewConsensus(
 		recv,
 		gov,
 		nodeSetCache,
+		db,
 		logger)
 	recv.cfgModule = cfgModule
 	// Construct Consensus instance.
@@ -490,6 +491,7 @@ func NewConsensusFromSyncer(
 		recv,
 		gov,
 		nodeSetCache,
+		db,
 		logger)
 	recv.cfgModule = cfgModule
 	// Setup Consensus instance.
@@ -576,7 +578,7 @@ func (con *Consensus) prepare(initBlock *types.Block) error {
 	}
 	if _, exist := dkgSet[con.ID]; exist {
 		con.logger.Info("Selected as DKG set", "round", initRound)
-		con.cfgModule.registerDKG(initRound, int(initConfig.DKGSetSize)/3+1)
+		con.cfgModule.registerDKG(initRound, getDKGThreshold(initConfig))
 		con.event.RegisterTime(con.dMoment.Add(initConfig.RoundInterval/4),
 			func(time.Time) {
 				con.runDKG(initRound, initConfig)
@@ -742,8 +744,7 @@ func (con *Consensus) initialRound(
 					return
 				}
 				con.logger.Info("Selected as DKG set", "round", nextRound)
-				con.cfgModule.registerDKG(
-					nextRound, int(config.DKGSetSize/3)+1)
+				con.cfgModule.registerDKG(nextRound, getDKGThreshold(config))
 				con.event.RegisterTime(
 					startTime.Add(config.RoundInterval*2/3),
 					func(time.Time) {
@@ -1003,6 +1004,14 @@ func (con *Consensus) preProcessBlock(b *types.Block) (err error) {
 
 // deliverBlock deliver a block to application layer.
 func (con *Consensus) deliverBlock(b *types.Block) {
+	if err := con.db.UpdateBlock(*b); err != nil {
+		panic(err)
+	}
+	if err := con.db.PutCompactionChainTipInfo(
+		b.Hash, b.Finalization.Height); err != nil {
+		panic(err)
+	}
+	con.cfgModule.untouchTSigHash(b.Hash)
 	con.logger.Debug("Calling Application.BlockDelivered", "block", b)
 	con.app.BlockDelivered(b.Hash, b.Position, b.Finalization.Clone())
 	if b.Position.Round == con.roundToNotify {
@@ -1032,6 +1041,9 @@ func (con *Consensus) deliverBlock(b *types.Block) {
 			con.roundToNotify, b.Finalization.Height)
 		con.roundToNotify++
 	}
+	if con.debugApp != nil {
+		con.debugApp.BlockReady(b.Hash)
+	}
 }
 
 // processBlock is the entry point to submit one block to a Consensus instance.
@@ -1072,14 +1084,7 @@ func (con *Consensus) processBlock(block *types.Block) (err error) {
 		"delivered", con.ccModule.lastDeliveredBlock(),
 		"pending", con.ccModule.lastPendingBlock())
 	for _, b := range deliveredBlocks {
-		if err = con.db.UpdateBlock(*b); err != nil {
-			panic(err)
-		}
-		con.cfgModule.untouchTSigHash(b.Hash)
 		con.deliverBlock(b)
-		if con.debugApp != nil {
-			con.debugApp.BlockReady(b.Hash)
-		}
 	}
 	if err = con.lattice.PurgeBlocks(deliveredBlocks); err != nil {
 		return
diff --git a/vendor/github.com/dexon-foundation/dexon-consensus/core/crypto/dkg/utils.go b/vendor/github.com/dexon-foundation/dexon-consensus/core/crypto/dkg/utils.go
index fa4ad9f05..9e470f0cf 100644
--- a/vendor/github.com/dexon-foundation/dexon-consensus/core/crypto/dkg/utils.go
+++ b/vendor/github.com/dexon-foundation/dexon-consensus/core/crypto/dkg/utils.go
@@ -18,7 +18,9 @@
 package dkg
 
 import (
+	"encoding/binary"
 	"fmt"
+	"math/rand"
 
 	"github.com/dexon-foundation/bls/ffi/go/bls"
 
@@ -69,3 +71,22 @@ func RecoverGroupPublicKey(pubShares []*PublicKeyShares) *PublicKey {
 	}
 	return pub
 }
+
+// NewRandomPrivateKeyShares constructs a private key shares randomly.
+func NewRandomPrivateKeyShares() *PrivateKeyShares {
+	// Generate IDs.
+	rndIDs := make(IDs, 0, 10)
+	for i := range rndIDs {
+		id := make([]byte, 8)
+		binary.LittleEndian.PutUint64(id, rand.Uint64())
+		rndIDs[i] = NewID(id)
+	}
+	prvShares := NewEmptyPrivateKeyShares()
+	prvShares.SetParticipants(rndIDs)
+	for _, id := range rndIDs {
+		if err := prvShares.AddShare(id, NewPrivateKey()); err != nil {
+			panic(err)
+		}
+	}
+	return prvShares
+}
diff --git a/vendor/github.com/dexon-foundation/dexon-consensus/core/db/interfaces.go b/vendor/github.com/dexon-foundation/dexon-consensus/core/db/interfaces.go
index 5e13dc604..ebbbbd475 100644
--- a/vendor/github.com/dexon-foundation/dexon-consensus/core/db/interfaces.go
+++ b/vendor/github.com/dexon-foundation/dexon-consensus/core/db/interfaces.go
@@ -22,6 +22,7 @@ import (
 	"fmt"
 
 	"github.com/dexon-foundation/dexon-consensus/common"
+	"github.com/dexon-foundation/dexon-consensus/core/crypto/dkg"
 	"github.com/dexon-foundation/dexon-consensus/core/types"
 )
 
@@ -38,6 +39,17 @@ var (
 	ErrClosed = fmt.Errorf("db closed")
 	// ErrNotImplemented is the error that some interface is not implemented.
 	ErrNotImplemented = fmt.Errorf("not implemented")
+	// ErrInvalidCompactionChainTipHeight means the newly updated height of
+	// the tip of compaction chain is invalid, usually means it's smaller than
+	// current cached one.
+	ErrInvalidCompactionChainTipHeight = fmt.Errorf(
+		"invalid compaction chain tip height")
+	// ErrDKGPrivateKeyExists raised when attempting to save DKG private key
+	// that already saved.
+	ErrDKGPrivateKeyExists = errors.New("dkg private key exists")
+	// ErrDKGPrivateKeyDoesNotExist raised when the DKG private key of the
+	// requested round does not exists.
+	ErrDKGPrivateKeyDoesNotExist = errors.New("dkg private key does not exists")
 )
 
 // Database is the interface for a Database.
@@ -55,12 +67,23 @@ type Reader interface {
 	HasBlock(hash common.Hash) bool
 	GetBlock(hash common.Hash) (types.Block, error)
 	GetAllBlocks() (BlockIterator, error)
+
+	// GetCompactionChainTipInfo returns the block hash and finalization height
+	// of the tip block of compaction chain. Empty hash and zero height means
+	// the compaction chain is empty.
+	GetCompactionChainTipInfo() (common.Hash, uint64)
+
+	// DKG Private Key related methods.
+	HasDKGPrivateKey(round uint64) (bool, error)
+	GetDKGPrivateKey(round uint64) (dkg.PrivateKey, error)
 }
 
 // Writer defines the interface for writing blocks into DB.
 type Writer interface {
 	UpdateBlock(block types.Block) error
 	PutBlock(block types.Block) error
+	PutCompactionChainTipInfo(common.Hash, uint64) error
+	PutDKGPrivateKey(uint64, dkg.PrivateKey) error
 }
 
 // BlockIterator defines an iterator on blocks hold
diff --git a/vendor/github.com/dexon-foundation/dexon-consensus/core/db/level-db.go b/vendor/github.com/dexon-foundation/dexon-consensus/core/db/level-db.go
index 6983d3a5e..3b5994b26 100644
--- a/vendor/github.com/dexon-foundation/dexon-consensus/core/db/level-db.go
+++ b/vendor/github.com/dexon-foundation/dexon-consensus/core/db/level-db.go
@@ -18,14 +18,27 @@
 package db
 
 import (
-	"encoding/json"
+	"encoding/binary"
 
 	"github.com/syndtr/goleveldb/leveldb"
 
 	"github.com/dexon-foundation/dexon-consensus/common"
+	"github.com/dexon-foundation/dexon-consensus/core/crypto/dkg"
 	"github.com/dexon-foundation/dexon-consensus/core/types"
+	"github.com/dexon-foundation/dexon/rlp"
 )
 
+var (
+	blockKeyPrefix            = []byte("b-")
+	compactionChainTipInfoKey = []byte("cc-tip")
+	dkgPrivateKeyKeyPrefix    = []byte("dkg-prvs")
+)
+
+type compactionChainTipInfo struct {
+	Height uint64      `json:"height"`
+	Hash   common.Hash `json:"hash"`
+}
+
 // LevelDBBackedDB is a leveldb backed DB implementation.
 type LevelDBBackedDB struct {
 	db *leveldb.DB
@@ -50,7 +63,7 @@ func (lvl *LevelDBBackedDB) Close() error {
 
 // HasBlock implements the Reader.Has method.
 func (lvl *LevelDBBackedDB) HasBlock(hash common.Hash) bool {
-	exists, err := lvl.db.Has([]byte(hash[:]), nil)
+	exists, err := lvl.internalHasBlock(lvl.getBlockKey(hash))
 	if err != nil {
 		// TODO(missionliao): Modify the interface to return error.
 		panic(err)
@@ -58,18 +71,25 @@ func (lvl *LevelDBBackedDB) HasBlock(hash common.Hash) bool {
 	return exists
 }
 
+func (lvl *LevelDBBackedDB) internalHasBlock(key []byte) (bool, error) {
+	exists, err := lvl.db.Has(key, nil)
+	if err != nil {
+		return false, err
+	}
+	return exists, nil
+}
+
 // GetBlock implements the Reader.GetBlock method.
 func (lvl *LevelDBBackedDB) GetBlock(
 	hash common.Hash) (block types.Block, err error) {
-
-	queried, err := lvl.db.Get([]byte(hash[:]), nil)
+	queried, err := lvl.db.Get(lvl.getBlockKey(hash), nil)
 	if err != nil {
 		if err == leveldb.ErrNotFound {
 			err = ErrBlockDoesNotExist
 		}
 		return
 	}
-	err = json.Unmarshal(queried, &block)
+	err = rlp.DecodeBytes(queried, &block)
 	if err != nil {
 		return
 	}
@@ -80,20 +100,20 @@ func (lvl *LevelDBBackedDB) GetBlock(
 func (lvl *LevelDBBackedDB) UpdateBlock(block types.Block) (err error) {
 	// NOTE: we didn't handle changes of block hash (and it
 	//       should not happen).
-	marshaled, err := json.Marshal(&block)
+	marshaled, err := rlp.EncodeToBytes(&block)
 	if err != nil {
 		return
 	}
-
-	if !lvl.HasBlock(block.Hash) {
+	blockKey := lvl.getBlockKey(block.Hash)
+	exists, err := lvl.internalHasBlock(blockKey)
+	if err != nil {
+		return
+	}
+	if !exists {
 		err = ErrBlockDoesNotExist
 		return
 	}
-	err = lvl.db.Put(
-		[]byte(block.Hash[:]),
-		marshaled,
-		nil)
-	if err != nil {
+	if err = lvl.db.Put(blockKey, marshaled, nil); err != nil {
 		return
 	}
 	return
@@ -101,19 +121,20 @@ func (lvl *LevelDBBackedDB) UpdateBlock(block types.Block) (err error) {
 
 // PutBlock implements the Writer.PutBlock method.
 func (lvl *LevelDBBackedDB) PutBlock(block types.Block) (err error) {
-	marshaled, err := json.Marshal(&block)
+	marshaled, err := rlp.EncodeToBytes(&block)
 	if err != nil {
 		return
 	}
-	if lvl.HasBlock(block.Hash) {
+	blockKey := lvl.getBlockKey(block.Hash)
+	exists, err := lvl.internalHasBlock(blockKey)
+	if err != nil {
+		return
+	}
+	if exists {
 		err = ErrBlockExists
 		return
 	}
-	err = lvl.db.Put(
-		[]byte(block.Hash[:]),
-		marshaled,
-		nil)
-	if err != nil {
+	if err = lvl.db.Put(blockKey, marshaled, nil); err != nil {
 		return
 	}
 	return
@@ -125,3 +146,118 @@ func (lvl *LevelDBBackedDB) GetAllBlocks() (BlockIterator, error) {
 	// TODO (mission): Implement this part via goleveldb's iterator.
 	return nil, ErrNotImplemented
 }
+
+// PutCompactionChainTipInfo saves tip of compaction chain into the database.
+func (lvl *LevelDBBackedDB) PutCompactionChainTipInfo(
+	blockHash common.Hash, height uint64) error {
+	marshaled, err := rlp.EncodeToBytes(&compactionChainTipInfo{
+		Hash:   blockHash,
+		Height: height,
+	})
+	if err != nil {
+		return err
+	}
+	// Check current cached tip info to make sure the one to be updated is
+	// valid.
+	info, err := lvl.internalGetCompactionChainTipInfo()
+	if err != nil {
+		return err
+	}
+	if info.Height >= height {
+		return ErrInvalidCompactionChainTipHeight
+	}
+	if err = lvl.db.Put(compactionChainTipInfoKey, marshaled, nil); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (lvl *LevelDBBackedDB) internalGetCompactionChainTipInfo() (
+	info compactionChainTipInfo, err error) {
+	queried, err := lvl.db.Get(compactionChainTipInfoKey, nil)
+	if err != nil {
+		if err == leveldb.ErrNotFound {
+			err = nil
+		}
+		return
+	}
+	if err = rlp.DecodeBytes(queried, &info); err != nil {
+		return
+	}
+	return
+}
+
+// GetCompactionChainTipInfo get the tip info of compaction chain into the
+// database.
+func (lvl *LevelDBBackedDB) GetCompactionChainTipInfo() (
+	hash common.Hash, height uint64) {
+	info, err := lvl.internalGetCompactionChainTipInfo()
+	if err != nil {
+		panic(err)
+	}
+	hash, height = info.Hash, info.Height
+	return
+}
+
+// HasDKGPrivateKey check existence of DKG private key of one round.
+func (lvl *LevelDBBackedDB) HasDKGPrivateKey(round uint64) (bool, error) {
+	exists, err := lvl.db.Has(lvl.getDKGPrivateKeyKey(round), nil)
+	if err != nil {
+		return false, err
+	}
+	return exists, nil
+}
+
+// GetDKGPrivateKey get DKG private key of one round.
+func (lvl *LevelDBBackedDB) GetDKGPrivateKey(round uint64) (
+	prv dkg.PrivateKey, err error) {
+	queried, err := lvl.db.Get(lvl.getDKGPrivateKeyKey(round), nil)
+	if err != nil {
+		if err == leveldb.ErrNotFound {
+			err = ErrDKGPrivateKeyDoesNotExist
+		}
+		return
+	}
+	if err = rlp.DecodeBytes(queried, &prv); err != nil {
+		return
+	}
+	return
+}
+
+// PutDKGPrivateKey save DKG private key of one round.
+func (lvl *LevelDBBackedDB) PutDKGPrivateKey(
+	round uint64, prv dkg.PrivateKey) error {
+	// Check existence.
+	exists, err := lvl.HasDKGPrivateKey(round)
+	if err != nil {
+		return err
+	}
+	if exists {
+		return ErrDKGPrivateKeyExists
+	}
+	marshaled, err := rlp.EncodeToBytes(&prv)
+	if err != nil {
+		return err
+	}
+	if err := lvl.db.Put(
+		lvl.getDKGPrivateKeyKey(round), marshaled, nil); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (lvl *LevelDBBackedDB) getBlockKey(hash common.Hash) (ret []byte) {
+	ret = make([]byte, len(blockKeyPrefix)+len(hash[:]))
+	copy(ret, blockKeyPrefix)
+	copy(ret[len(blockKeyPrefix):], hash[:])
+	return
+}
+
+func (lvl *LevelDBBackedDB) getDKGPrivateKeyKey(
+	round uint64) (ret []byte) {
+	ret = make([]byte, len(dkgPrivateKeyKeyPrefix)+8)
+	copy(ret, dkgPrivateKeyKeyPrefix)
+	binary.LittleEndian.PutUint64(
+		ret[len(dkgPrivateKeyKeyPrefix):], round)
+	return
+}
diff --git a/vendor/github.com/dexon-foundation/dexon-consensus/core/db/memory.go b/vendor/github.com/dexon-foundation/dexon-consensus/core/db/memory.go
index 4246e4fe1..7393de9db 100644
--- a/vendor/github.com/dexon-foundation/dexon-consensus/core/db/memory.go
+++ b/vendor/github.com/dexon-foundation/dexon-consensus/core/db/memory.go
@@ -24,6 +24,7 @@ import (
 	"sync"
 
 	"github.com/dexon-foundation/dexon-consensus/common"
+	"github.com/dexon-foundation/dexon-consensus/core/crypto/dkg"
 	"github.com/dexon-foundation/dexon-consensus/core/types"
 )
 
@@ -41,10 +42,15 @@ func (seq *blockSeqIterator) NextBlock() (types.Block, error) {
 
 // MemBackedDB is a memory backed DB implementation.
 type MemBackedDB struct {
-	blocksMutex        sync.RWMutex
-	blockHashSequence  common.Hashes
-	blocksByHash       map[common.Hash]*types.Block
-	persistantFilePath string
+	blocksLock               sync.RWMutex
+	blockHashSequence        common.Hashes
+	blocksByHash             map[common.Hash]*types.Block
+	compactionChainTipLock   sync.RWMutex
+	compactionChainTipHash   common.Hash
+	compactionChainTipHeight uint64
+	dkgPrivateKeysLock       sync.RWMutex
+	dkgPrivateKeys           map[uint64]*dkg.PrivateKey
+	persistantFilePath       string
 }
 
 // NewMemBackedDB initialize a memory-backed database.
@@ -53,6 +59,7 @@ func NewMemBackedDB(persistantFilePath ...string) (
 	dbInst = &MemBackedDB{
 		blockHashSequence: common.Hashes{},
 		blocksByHash:      make(map[common.Hash]*types.Block),
+		dkgPrivateKeys:    make(map[uint64]*dkg.PrivateKey),
 	}
 	if len(persistantFilePath) == 0 || len(persistantFilePath[0]) == 0 {
 		return
@@ -87,8 +94,8 @@ func NewMemBackedDB(persistantFilePath ...string) (
 
 // HasBlock returns wheter or not the DB has a block identified with the hash.
 func (m *MemBackedDB) HasBlock(hash common.Hash) bool {
-	m.blocksMutex.RLock()
-	defer m.blocksMutex.RUnlock()
+	m.blocksLock.RLock()
+	defer m.blocksLock.RUnlock()
 
 	_, ok := m.blocksByHash[hash]
 	return ok
@@ -96,8 +103,8 @@ func (m *MemBackedDB) HasBlock(hash common.Hash) bool {
 
 // GetBlock returns a block given a hash.
 func (m *MemBackedDB) GetBlock(hash common.Hash) (types.Block, error) {
-	m.blocksMutex.RLock()
-	defer m.blocksMutex.RUnlock()
+	m.blocksLock.RLock()
+	defer m.blocksLock.RUnlock()
 
 	return m.internalGetBlock(hash)
 }
@@ -116,8 +123,8 @@ func (m *MemBackedDB) PutBlock(block types.Block) error {
 		return ErrBlockExists
 	}
 
-	m.blocksMutex.Lock()
-	defer m.blocksMutex.Unlock()
+	m.blocksLock.Lock()
+	defer m.blocksLock.Unlock()
 
 	m.blockHashSequence = append(m.blockHashSequence, block.Hash)
 	m.blocksByHash[block.Hash] = &block
@@ -130,13 +137,66 @@ func (m *MemBackedDB) UpdateBlock(block types.Block) error {
 		return ErrBlockDoesNotExist
 	}
 
-	m.blocksMutex.Lock()
-	defer m.blocksMutex.Unlock()
+	m.blocksLock.Lock()
+	defer m.blocksLock.Unlock()
 
 	m.blocksByHash[block.Hash] = &block
 	return nil
 }
 
+// PutCompactionChainTipInfo saves tip of compaction chain into the database.
+func (m *MemBackedDB) PutCompactionChainTipInfo(
+	blockHash common.Hash, height uint64) error {
+	m.compactionChainTipLock.Lock()
+	defer m.compactionChainTipLock.Unlock()
+	if m.compactionChainTipHeight >= height {
+		return ErrInvalidCompactionChainTipHeight
+	}
+	m.compactionChainTipHeight = height
+	m.compactionChainTipHash = blockHash
+	return nil
+}
+
+// GetCompactionChainTipInfo get the tip info of compaction chain into the
+// database.
+func (m *MemBackedDB) GetCompactionChainTipInfo() (
+	hash common.Hash, height uint64) {
+	m.compactionChainTipLock.RLock()
+	defer m.compactionChainTipLock.RUnlock()
+	return m.compactionChainTipHash, m.compactionChainTipHeight
+}
+
+// HasDKGPrivateKey check existence of DKG private key of one round.
+func (m *MemBackedDB) HasDKGPrivateKey(round uint64) (bool, error) {
+	m.dkgPrivateKeysLock.RLock()
+	defer m.dkgPrivateKeysLock.RUnlock()
+	_, exists := m.dkgPrivateKeys[round]
+	return exists, nil
+}
+
+// GetDKGPrivateKey get DKG private key of one round.
+func (m *MemBackedDB) GetDKGPrivateKey(round uint64) (
+	dkg.PrivateKey, error) {
+	m.dkgPrivateKeysLock.RLock()
+	defer m.dkgPrivateKeysLock.RUnlock()
+	if prv, exists := m.dkgPrivateKeys[round]; exists {
+		return *prv, nil
+	}
+	return dkg.PrivateKey{}, ErrDKGPrivateKeyDoesNotExist
+}
+
+// PutDKGPrivateKey save DKG private key of one round.
+func (m *MemBackedDB) PutDKGPrivateKey(
+	round uint64, prv dkg.PrivateKey) error {
+	m.dkgPrivateKeysLock.Lock()
+	defer m.dkgPrivateKeysLock.Unlock()
+	if _, exists := m.dkgPrivateKeys[round]; exists {
+		return ErrDKGPrivateKeyExists
+	}
+	m.dkgPrivateKeys[round] = &prv
+	return nil
+}
+
 // Close implement Closer interface, which would release allocated resource.
 func (m *MemBackedDB) Close() (err error) {
 	// Save internal state to a pretty-print json file. It's a temporary way
@@ -145,8 +205,8 @@ func (m *MemBackedDB) Close() (err error) {
 		return
 	}
 
-	m.blocksMutex.RLock()
-	defer m.blocksMutex.RUnlock()
+	m.blocksLock.RLock()
+	defer m.blocksLock.RUnlock()
 
 	toDump := struct {
 		Sequence common.Hashes
@@ -167,8 +227,8 @@ func (m *MemBackedDB) Close() (err error) {
 }
 
 func (m *MemBackedDB) getBlockByIndex(idx int) (types.Block, error) {
-	m.blocksMutex.RLock()
-	defer m.blocksMutex.RUnlock()
+	m.blocksLock.RLock()
+	defer m.blocksLock.RUnlock()
 
 	if idx >= len(m.blockHashSequence) {
 		return types.Block{}, ErrIterationFinished
diff --git a/vendor/github.com/dexon-foundation/dexon-consensus/core/dkg-tsig-protocol.go b/vendor/github.com/dexon-foundation/dexon-consensus/core/dkg-tsig-protocol.go
index 6645ecbae..8e03cbbda 100644
--- a/vendor/github.com/dexon-foundation/dexon-consensus/core/dkg-tsig-protocol.go
+++ b/vendor/github.com/dexon-foundation/dexon-consensus/core/dkg-tsig-protocol.go
@@ -378,16 +378,21 @@ func NewDKGGroupPublicKey(
 
 	// Calculate qualify members.
 	disqualifyIDs := map[types.NodeID]struct{}{}
-	complaintsByID := map[types.NodeID]int{}
+	complaintsByID := map[types.NodeID]map[types.NodeID]struct{}{}
 	for _, complaint := range complaints {
 		if complaint.IsNack() {
-			complaintsByID[complaint.PrivateShare.ProposerID]++
+			if _, exist := complaintsByID[complaint.PrivateShare.ProposerID]; !exist {
+				complaintsByID[complaint.PrivateShare.ProposerID] =
+					make(map[types.NodeID]struct{})
+			}
+			complaintsByID[complaint.PrivateShare.ProposerID][complaint.ProposerID] =
+				struct{}{}
 		} else {
 			disqualifyIDs[complaint.PrivateShare.ProposerID] = struct{}{}
 		}
 	}
-	for nID, num := range complaintsByID {
-		if num > threshold {
+	for nID, complaints := range complaintsByID {
+		if len(complaints) > threshold {
 			disqualifyIDs[nID] = struct{}{}
 		}
 	}
diff --git a/vendor/github.com/dexon-foundation/dexon-consensus/core/utils.go b/vendor/github.com/dexon-foundation/dexon-consensus/core/utils.go
index 2ef243757..671d68018 100644
--- a/vendor/github.com/dexon-foundation/dexon-consensus/core/utils.go
+++ b/vendor/github.com/dexon-foundation/dexon-consensus/core/utils.go
@@ -231,3 +231,7 @@ func isCircleCI() bool {
 func isTravisCI() bool {
 	return isCI() && os.Getenv("TRAVIS") == "true"
 }
+
+func getDKGThreshold(config *types.Config) int {
+	return int(config.DKGSetSize/3) + 1
+}
diff --git a/vendor/vendor.json b/vendor/vendor.json
index 81119dc09..add9ce181 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -105,14 +105,14 @@
 		{
 			"checksumSHA1": "65L1yf+f0OCiLFniljqfRxVdsQA=",
 			"path": "github.com/dexon-foundation/dexon-consensus/common",
-			"revision": "0ead4a7c012af9ddaa4a934729e216539d2caeb1",
-			"revisionTime": "2018-12-13T03:01:43Z"
+			"revision": "99d72382687196fb15ea6ab0fcf297b9ab10ac46",
+			"revisionTime": "2018-12-16T06:44:15Z"
 		},
 		{
-			"checksumSHA1": "7Oa+i0v4Xtpk+mA1ANSwPzOZrZo=",
+			"checksumSHA1": "jZLh+ZsuMIiMuksK9c/5QpMQ2IM=",
 			"path": "github.com/dexon-foundation/dexon-consensus/core",
-			"revision": "0ead4a7c012af9ddaa4a934729e216539d2caeb1",
-			"revisionTime": "2018-12-13T03:01:43Z"
+			"revision": "99d72382687196fb15ea6ab0fcf297b9ab10ac46",
+			"revisionTime": "2018-12-16T06:44:15Z"
 		},
 		{
 			"checksumSHA1": "v4fKR7uhoyufi6hAVO44cFEb+tY=",
@@ -123,44 +123,44 @@
 		{
 			"checksumSHA1": "tQSbYCu5P00lUhKsx3IbBZCuSLY=",
 			"path": "github.com/dexon-foundation/dexon-consensus/core/crypto",
-			"revision": "0ead4a7c012af9ddaa4a934729e216539d2caeb1",
-			"revisionTime": "2018-12-13T03:01:43Z"
+			"revision": "99d72382687196fb15ea6ab0fcf297b9ab10ac46",
+			"revisionTime": "2018-12-16T06:44:15Z"
 		},
 		{
-			"checksumSHA1": "p2jOAulavUU2xyj018pYPHlj8XA=",
+			"checksumSHA1": "W2P7pkuJ+26BpJg03K4Y0nB5obI=",
 			"path": "github.com/dexon-foundation/dexon-consensus/core/crypto/dkg",
-			"revision": "0ead4a7c012af9ddaa4a934729e216539d2caeb1",
-			"revisionTime": "2018-12-13T03:01:43Z"
+			"revision": "99d72382687196fb15ea6ab0fcf297b9ab10ac46",
+			"revisionTime": "2018-12-16T06:44:15Z"
 		},
 		{
 			"checksumSHA1": "6Pf6caC8LTNCI7IflFmglKYnxYo=",
 			"path": "github.com/dexon-foundation/dexon-consensus/core/crypto/ecdsa",
-			"revision": "0ead4a7c012af9ddaa4a934729e216539d2caeb1",
-			"revisionTime": "2018-12-13T03:01:43Z"
+			"revision": "99d72382687196fb15ea6ab0fcf297b9ab10ac46",
+			"revisionTime": "2018-12-16T06:44:15Z"
 		},
 		{
-			"checksumSHA1": "oE4WEMp92OrJrujzd3XdQEkPiDI=",
+			"checksumSHA1": "trkFVPLd7UFFUzL8bn6KuvFU9gE=",
 			"path": "github.com/dexon-foundation/dexon-consensus/core/db",
-			"revision": "0ead4a7c012af9ddaa4a934729e216539d2caeb1",
-			"revisionTime": "2018-12-13T03:01:43Z"
+			"revision": "99d72382687196fb15ea6ab0fcf297b9ab10ac46",
+			"revisionTime": "2018-12-16T06:44:15Z"
 		},
 		{
 			"checksumSHA1": "Z079qQV+aQV9A3kSJ0LbFjx5VO4=",
 			"path": "github.com/dexon-foundation/dexon-consensus/core/types",
-			"revision": "0ead4a7c012af9ddaa4a934729e216539d2caeb1",
-			"revisionTime": "2018-12-13T03:01:43Z"
+			"revision": "99d72382687196fb15ea6ab0fcf297b9ab10ac46",
+			"revisionTime": "2018-12-16T06:44:15Z"
 		},
 		{
 			"checksumSHA1": "Sn3PAYsblIXmr7gVKDzxnoBPku4=",
 			"path": "github.com/dexon-foundation/dexon-consensus/core/types/dkg",
-			"revision": "0ead4a7c012af9ddaa4a934729e216539d2caeb1",
-			"revisionTime": "2018-12-13T03:01:43Z"
+			"revision": "99d72382687196fb15ea6ab0fcf297b9ab10ac46",
+			"revisionTime": "2018-12-16T06:44:15Z"
 		},
 		{
 			"checksumSHA1": "A7UQ+7rv9FuElmFBEn/ZdhBqFKI=",
 			"path": "github.com/dexon-foundation/dexon-consensus/core/utils",
-			"revision": "0ead4a7c012af9ddaa4a934729e216539d2caeb1",
-			"revisionTime": "2018-12-13T03:01:43Z"
+			"revision": "99d72382687196fb15ea6ab0fcf297b9ab10ac46",
+			"revisionTime": "2018-12-16T06:44:15Z"
 		},
 		{
 			"checksumSHA1": "TAkwduKZqLyimyTPPWIllZWYFuE=",