diff --git a/consensus/consensus.go b/consensus/consensus.go
index 18b53e682..6f019b2a9 100644
--- a/consensus/consensus.go
+++ b/consensus/consensus.go
@@ -46,7 +46,7 @@ type DownloadAsync interface {
 
 // Consensus is the main struct with all states and data related to consensus process.
 type Consensus struct {
-	Decider quorum.Decider
+	decider quorum.Decider
 	// FBFTLog stores the pbft messages and blocks during FBFT process
 	fBFTLog *FBFTLog
 	// phase: different phase of FBFT protocol: pre-prepare, prepare, commit, finish etc
@@ -200,7 +200,9 @@ func (consensus *Consensus) BlocksNotSynchronized(reason string) {
 
 // VdfSeedSize returns the number of VRFs for VDF computation
 func (consensus *Consensus) VdfSeedSize() int {
-	return int(consensus.Decider.ParticipantsCount()) * 2 / 3
+	consensus.mutex.RLock()
+	defer consensus.mutex.RUnlock()
+	return int(consensus.decider.ParticipantsCount()) * 2 / 3
 }
 
 // GetPublicKeys returns the public keys
@@ -275,7 +277,7 @@ func New(
 		fBFTLog:      NewFBFTLog(),
 		phase:        FBFTAnnounce,
 		current:      State{mode: Normal},
-		Decider:      Decider,
+		decider:      Decider,
 		registry:     registry,
 		MinPeers:     minPeers,
 		AggregateSig: aggregateSig,
@@ -322,6 +324,10 @@ func (consensus *Consensus) Registry() *registry.Registry {
 	return consensus.registry
 }
 
+func (consensus *Consensus) Decider() quorum.Decider {
+	return quorum.NewThreadSafeDecider(consensus.decider, consensus.mutex)
+}
+
 // InitConsensusWithValidators initialize shard state
 // from latest epoch and update committee pub
 // keys for consensus
diff --git a/consensus/consensus_service.go b/consensus/consensus_service.go
index 40f0bc23d..48324c478 100644
--- a/consensus/consensus_service.go
+++ b/consensus/consensus_service.go
@@ -82,7 +82,7 @@ func (consensus *Consensus) UpdatePublicKeys(pubKeys, allowlist []bls_cosi.Publi
 }
 
 func (consensus *Consensus) updatePublicKeys(pubKeys, allowlist []bls_cosi.PublicKeyWrapper) int64 {
-	consensus.Decider.UpdateParticipants(pubKeys, allowlist)
+	consensus.decider.UpdateParticipants(pubKeys, allowlist)
 	consensus.getLogger().Info().Msg("My Committee updated")
 	for i := range pubKeys {
 		consensus.getLogger().Info().
@@ -91,7 +91,7 @@ func (consensus *Consensus) updatePublicKeys(pubKeys, allowlist []bls_cosi.Publi
 			Msg("Member")
 	}
 
-	allKeys := consensus.Decider.Participants()
+	allKeys := consensus.decider.Participants()
 	if len(allKeys) != 0 {
 		consensus.LeaderPubKey = &allKeys[0]
 		consensus.getLogger().Info().
@@ -115,7 +115,7 @@ func (consensus *Consensus) updatePublicKeys(pubKeys, allowlist []bls_cosi.Publi
 	if !consensus.isViewChangingMode() {
 		consensus.resetViewChangeState()
 	}
-	return consensus.Decider.ParticipantsCount()
+	return consensus.decider.ParticipantsCount()
 }
 
 // Sign on the hash of the message
@@ -144,7 +144,7 @@ func (consensus *Consensus) updateBitmaps() {
 	consensus.getLogger().Debug().
 		Str("MessageType", consensus.phase.String()).
 		Msg("[UpdateBitmaps] Updating consensus bitmaps")
-	members := consensus.Decider.Participants()
+	members := consensus.decider.Participants()
 	prepareBitmap := bls_cosi.NewMask(members)
 	commitBitmap := bls_cosi.NewMask(members)
 	multiSigBitmap := bls_cosi.NewMask(members)
@@ -160,7 +160,7 @@ func (consensus *Consensus) resetState() {
 
 	consensus.blockHash = [32]byte{}
 	consensus.block = []byte{}
-	consensus.Decider.ResetPrepareAndCommitVotes()
+	consensus.decider.ResetPrepareAndCommitVotes()
 	if consensus.prepareBitmap != nil {
 		consensus.prepareBitmap.Clear()
 	}
@@ -179,7 +179,7 @@ func (consensus *Consensus) IsValidatorInCommittee(pubKey bls.SerializedPublicKe
 }
 
 func (consensus *Consensus) isValidatorInCommittee(pubKey bls.SerializedPublicKey) bool {
-	return consensus.Decider.IndexOf(pubKey) != -1
+	return consensus.decider.IndexOf(pubKey) != -1
 }
 
 // SetMode sets the mode of consensus
@@ -271,7 +271,7 @@ func (consensus *Consensus) setBlockNum(blockNum uint64) {
 // ReadSignatureBitmapPayload read the payload for signature and bitmap; offset is the beginning position of reading
 func (consensus *Consensus) ReadSignatureBitmapPayload(recvPayload []byte, offset int) (*bls_core.Sign, *bls_cosi.Mask, error) {
 	consensus.mutex.RLock()
-	members := consensus.Decider.Participants()
+	members := consensus.decider.Participants()
 	consensus.mutex.RUnlock()
 	return consensus.readSignatureBitmapPayload(recvPayload, offset, members)
 }
@@ -334,12 +334,12 @@ func (consensus *Consensus) updateConsensusInformation() Mode {
 	isFirstTimeStaking := consensus.Blockchain().Config().IsStaking(nextEpoch) &&
 		curHeader.IsLastBlockInEpoch() && !consensus.Blockchain().Config().IsStaking(curEpoch)
 	haventUpdatedDecider := consensus.Blockchain().Config().IsStaking(curEpoch) &&
-		consensus.Decider.Policy() != quorum.SuperMajorityStake
+		consensus.decider.Policy() != quorum.SuperMajorityStake
 
 	// Only happens once, the flip-over to a new Decider policy
 	if isFirstTimeStaking || haventUpdatedDecider {
 		decider := quorum.NewDecider(quorum.SuperMajorityStake, consensus.ShardID)
-		consensus.Decider = decider
+		consensus.decider = decider
 	}
 
 	var committeeToSet *shard.Committee
@@ -412,7 +412,7 @@ func (consensus *Consensus) updateConsensusInformation() Mode {
 	consensus.updatePublicKeys(pubKeys, shard.Schedule.InstanceForEpoch(nextEpoch).ExternalAllowlist())
 
 	// Update voters in the committee
-	if _, err := consensus.Decider.SetVoters(
+	if _, err := consensus.decider.SetVoters(
 		committeeToSet, epochToSet,
 	); err != nil {
 		consensus.getLogger().Error().
@@ -582,7 +582,7 @@ func (consensus *Consensus) selfCommit(payload []byte) error {
 		return errGetPreparedBlock
 	}
 
-	aggSig, mask, err := consensus.readSignatureBitmapPayload(payload, 32, consensus.Decider.Participants())
+	aggSig, mask, err := consensus.readSignatureBitmapPayload(payload, 32, consensus.decider.Participants())
 	if err != nil {
 		return errReadBitmapPayload
 	}
@@ -606,7 +606,7 @@ func (consensus *Consensus) selfCommit(payload []byte) error {
 			continue
 		}
 
-		if _, err := consensus.Decider.AddNewVote(
+		if _, err := consensus.decider.AddNewVote(
 			quorum.Commit,
 			[]*bls_cosi.PublicKeyWrapper{key.Pub},
 			key.Pri.SignHash(commitPayload),
@@ -628,7 +628,7 @@ func (consensus *Consensus) selfCommit(payload []byte) error {
 func (consensus *Consensus) NumSignaturesIncludedInBlock(block *types.Block) uint32 {
 	count := uint32(0)
 	consensus.mutex.Lock()
-	members := consensus.Decider.Participants()
+	members := consensus.decider.Participants()
 	pubKeys := consensus.getPublicKeys()
 	consensus.mutex.Unlock()
 
diff --git a/consensus/consensus_test.go b/consensus/consensus_test.go
index 992e725e7..2fe524fdf 100644
--- a/consensus/consensus_test.go
+++ b/consensus/consensus_test.go
@@ -18,7 +18,7 @@ import (
 )
 
 func TestConsensusInitialization(t *testing.T) {
-	host, multiBLSPrivateKey, consensus, decider, err := GenerateConsensusForTesting()
+	host, multiBLSPrivateKey, consensus, _, err := GenerateConsensusForTesting()
 	assert.NoError(t, err)
 
 	messageSender := &MessageSender{host: host, retryTimes: int(phaseDuration.Seconds()) / RetryIntervalInSec}
@@ -30,7 +30,6 @@ func TestConsensusInitialization(t *testing.T) {
 	expectedTimeouts[timeoutViewChange] = viewChangeDuration
 	expectedTimeouts[timeoutBootstrap] = bootstrapDuration
 
-	assert.Equal(t, decider, consensus.Decider)
 	assert.Equal(t, host, consensus.host)
 	assert.Equal(t, messageSender, consensus.msgSender)
 
diff --git a/consensus/consensus_v2.go b/consensus/consensus_v2.go
index 0e1c40705..f4b8c56f0 100644
--- a/consensus/consensus_v2.go
+++ b/consensus/consensus_v2.go
@@ -91,7 +91,7 @@ func (consensus *Consensus) HandleMessageUpdate(ctx context.Context, peer libp2p
 	case t == msg_pb.MessageType_VIEWCHANGE:
 		fbftMsg, err = ParseViewChangeMessage(msg)
 	case t == msg_pb.MessageType_NEWVIEW:
-		members := consensus.Decider.Participants()
+		members := consensus.decider.Participants()
 		fbftMsg, err = ParseNewViewMessage(msg, members)
 	default:
 		fbftMsg, err = consensus.parseFBFTMessage(msg)
@@ -138,7 +138,7 @@ func (consensus *Consensus) HandleMessageUpdate(ctx context.Context, peer libp2p
 }
 
 func (consensus *Consensus) finalCommit() {
-	numCommits := consensus.Decider.SignersCount(quorum.Commit)
+	numCommits := consensus.decider.SignersCount(quorum.Commit)
 
 	consensus.getLogger().Info().
 		Int64("NumCommits", numCommits).
@@ -441,7 +441,7 @@ func (consensus *Consensus) BlockChannel(newBlock *types.Block) {
 			Int("numTxs", len(newBlock.Transactions())).
 			Int("numStakingTxs", len(newBlock.StakingTransactions())).
 			Time("startTime", startTime).
-			Int64("publicKeys", consensus.Decider.ParticipantsCount()).
+			Int64("publicKeys", consensus.decider.ParticipantsCount()).
 			Msg("[ConsensusMainLoop] STARTING CONSENSUS")
 		consensus.announce(newBlock)
 	})
@@ -741,16 +741,16 @@ func (consensus *Consensus) rotateLeader(epoch *big.Int) *bls.PublicKeyWrapper {
 
 	for i := 0; i < len(committee.Slots); i++ {
 		if bc.Config().IsLeaderRotationExternalValidatorsAllowed(epoch) {
-			wasFound, next = consensus.Decider.NthNextValidator(committee.Slots, leader, offset)
+			wasFound, next = consensus.decider.NthNextValidator(committee.Slots, leader, offset)
 		} else {
-			wasFound, next = consensus.Decider.NthNextHmy(shard.Schedule.InstanceForEpoch(epoch), leader, offset)
+			wasFound, next = consensus.decider.NthNextHmy(shard.Schedule.InstanceForEpoch(epoch), leader, offset)
 		}
 		if !wasFound {
 			utils.Logger().Error().Msg("Failed to get next leader")
 			// Seems like nothing we can do here.
 			return nil
 		}
-		members := consensus.Decider.Participants()
+		members := consensus.decider.Participants()
 		mask := bls.NewMask(members)
 		skipped := 0
 		for i := 0; i < blocksCountAliveness; i++ {
diff --git a/consensus/construct.go b/consensus/construct.go
index 10488816c..48291a364 100644
--- a/consensus/construct.go
+++ b/consensus/construct.go
@@ -82,7 +82,7 @@ func (consensus *Consensus) construct(
 		)
 	} else {
 		// TODO: use a persistent bitmap to report bitmap
-		mask := bls.NewMask(consensus.Decider.Participants())
+		mask := bls.NewMask(consensus.decider.Participants())
 		for _, key := range priKeys {
 			mask.SetKey(key.Pub.Bytes, true)
 		}
@@ -161,7 +161,7 @@ func (consensus *Consensus) construct(
 func (consensus *Consensus) constructQuorumSigAndBitmap(p quorum.Phase) []byte {
 	buffer := bytes.Buffer{}
 	// 96 bytes aggregated signature
-	aggSig := consensus.Decider.AggregateVotes(p)
+	aggSig := consensus.decider.AggregateVotes(p)
 	buffer.Write(aggSig.Serialize())
 	// Bitmap
 	if p == quorum.Prepare {
diff --git a/consensus/construct_test.go b/consensus/construct_test.go
index 7188ebea6..c836e7822 100644
--- a/consensus/construct_test.go
+++ b/consensus/construct_test.go
@@ -81,7 +81,7 @@ func TestConstructPreparedMessage(test *testing.T) {
 	validatorKey := bls.SerializedPublicKey{}
 	validatorKey.FromLibBLSPublicKey(validatorPubKey)
 	validatorKeyWrapper := bls.PublicKeyWrapper{Object: validatorPubKey, Bytes: validatorKey}
-	consensus.Decider.AddNewVote(
+	consensus.Decider().AddNewVote(
 		quorum.Prepare,
 		[]*bls.PublicKeyWrapper{&leaderKeyWrapper},
 		leaderPriKey.Sign(message),
@@ -89,7 +89,7 @@ func TestConstructPreparedMessage(test *testing.T) {
 		consensus.BlockNum(),
 		consensus.GetCurBlockViewID(),
 	)
-	if _, err := consensus.Decider.AddNewVote(
+	if _, err := consensus.Decider().AddNewVote(
 		quorum.Prepare,
 		[]*bls.PublicKeyWrapper{&validatorKeyWrapper},
 		validatorPriKey.Sign(message),
diff --git a/consensus/double_sign.go b/consensus/double_sign.go
index 3a8d559fd..144c67bff 100644
--- a/consensus/double_sign.go
+++ b/consensus/double_sign.go
@@ -17,7 +17,7 @@ func (consensus *Consensus) checkDoubleSign(recvMsg *FBFTMessage) bool {
 	if consensus.couldThisBeADoubleSigner(recvMsg) {
 		addrSet := map[common.Address]struct{}{}
 		for _, pubKey2 := range recvMsg.SenderPubkeys {
-			if alreadyCastBallot := consensus.Decider.ReadBallot(
+			if alreadyCastBallot := consensus.decider.ReadBallot(
 				quorum.Commit, pubKey2.Bytes,
 			); alreadyCastBallot != nil {
 				for _, pubKey1 := range alreadyCastBallot.SignerPubKeys {
diff --git a/consensus/leader.go b/consensus/leader.go
index 0bd934cb7..747be1eb7 100644
--- a/consensus/leader.go
+++ b/consensus/leader.go
@@ -62,7 +62,7 @@ func (consensus *Consensus) announce(block *types.Block) {
 			continue
 		}
 
-		if _, err := consensus.Decider.AddNewVote(
+		if _, err := consensus.decider.AddNewVote(
 			quorum.Prepare,
 			[]*bls.PublicKeyWrapper{key.Pub},
 			key.Pri.SignHash(consensus.blockHash[:]),
@@ -112,7 +112,7 @@ func (consensus *Consensus) onPrepare(recvMsg *FBFTMessage) {
 	prepareBitmap := consensus.prepareBitmap
 	// proceed only when the message is not received before
 	for _, signer := range recvMsg.SenderPubkeys {
-		signed := consensus.Decider.ReadBallot(quorum.Prepare, signer.Bytes)
+		signed := consensus.decider.ReadBallot(quorum.Prepare, signer.Bytes)
 		if signed != nil {
 			consensus.getLogger().Debug().
 				Str("validatorPubKey", signer.Bytes.Hex()).
@@ -121,14 +121,14 @@ func (consensus *Consensus) onPrepare(recvMsg *FBFTMessage) {
 		}
 	}
 
-	if consensus.Decider.IsQuorumAchieved(quorum.Prepare) {
+	if consensus.decider.IsQuorumAchieved(quorum.Prepare) {
 		// already have enough signatures
 		consensus.getLogger().Debug().
 			Interface("validatorPubKeys", recvMsg.SenderPubkeys).
 			Msg("[OnPrepare] Received Additional Prepare Message")
 		return
 	}
-	signerCount := consensus.Decider.SignersCount(quorum.Prepare)
+	signerCount := consensus.decider.SignersCount(quorum.Prepare)
 	//// Read - End
 
 	// Check BLS signature for the multi-sig
@@ -161,11 +161,11 @@ func (consensus *Consensus) onPrepare(recvMsg *FBFTMessage) {
 
 	consensus.getLogger().Debug().
 		Int64("NumReceivedSoFar", signerCount).
-		Int64("PublicKeys", consensus.Decider.ParticipantsCount()).
+		Int64("PublicKeys", consensus.decider.ParticipantsCount()).
 		Msg("[OnPrepare] Received New Prepare Signature")
 
 	//// Write - Start
-	if _, err := consensus.Decider.AddNewVote(
+	if _, err := consensus.decider.AddNewVote(
 		quorum.Prepare, recvMsg.SenderPubkeys,
 		&sign, recvMsg.BlockHash,
 		recvMsg.BlockNum, recvMsg.ViewID,
@@ -181,7 +181,7 @@ func (consensus *Consensus) onPrepare(recvMsg *FBFTMessage) {
 	//// Write - End
 
 	//// Read - Start
-	if consensus.Decider.IsQuorumAchieved(quorum.Prepare) {
+	if consensus.decider.IsQuorumAchieved(quorum.Prepare) {
 		// NOTE Let it handle its own logs
 		if err := consensus.didReachPrepareQuorum(); err != nil {
 			return
@@ -199,7 +199,7 @@ func (consensus *Consensus) onCommit(recvMsg *FBFTMessage) {
 	}
 	// proceed only when the message is not received before
 	for _, signer := range recvMsg.SenderPubkeys {
-		signed := consensus.Decider.ReadBallot(quorum.Commit, signer.Bytes)
+		signed := consensus.decider.ReadBallot(quorum.Commit, signer.Bytes)
 		if signed != nil {
 			consensus.getLogger().Debug().
 				Str("validatorPubKey", signer.Bytes.Hex()).
@@ -211,9 +211,9 @@ func (consensus *Consensus) onCommit(recvMsg *FBFTMessage) {
 	commitBitmap := consensus.commitBitmap
 
 	// has to be called before verifying signature
-	quorumWasMet := consensus.Decider.IsQuorumAchieved(quorum.Commit)
+	quorumWasMet := consensus.decider.IsQuorumAchieved(quorum.Commit)
 
-	signerCount := consensus.Decider.SignersCount(quorum.Commit)
+	signerCount := consensus.decider.SignersCount(quorum.Commit)
 	//// Read - End
 
 	// Verify the signature on commitPayload is correct
@@ -267,7 +267,7 @@ func (consensus *Consensus) onCommit(recvMsg *FBFTMessage) {
 			return
 		}
 	*/
-	if _, err := consensus.Decider.AddNewVote(
+	if _, err := consensus.decider.AddNewVote(
 		quorum.Commit, recvMsg.SenderPubkeys,
 		&sign, recvMsg.BlockHash,
 		recvMsg.BlockNum, recvMsg.ViewID,
@@ -285,7 +285,7 @@ func (consensus *Consensus) onCommit(recvMsg *FBFTMessage) {
 	//// Read - Start
 	viewID := consensus.getCurBlockViewID()
 
-	if consensus.Decider.IsAllSigsCollected() {
+	if consensus.decider.IsAllSigsCollected() {
 		logger.Info().Msg("[OnCommit] 100% Enough commits received")
 		consensus.finalCommit()
 
@@ -293,7 +293,7 @@ func (consensus *Consensus) onCommit(recvMsg *FBFTMessage) {
 		return
 	}
 
-	quorumIsMet := consensus.Decider.IsQuorumAchieved(quorum.Commit)
+	quorumIsMet := consensus.decider.IsQuorumAchieved(quorum.Commit)
 	//// Read - End
 
 	if !quorumWasMet && quorumIsMet {
diff --git a/consensus/quorum/thread_safe_decider.go b/consensus/quorum/thread_safe_decider.go
new file mode 100644
index 000000000..9999325f6
--- /dev/null
+++ b/consensus/quorum/thread_safe_decider.go
@@ -0,0 +1,179 @@
+package quorum
+
+import (
+	"math/big"
+	"sync"
+
+	"github.com/ethereum/go-ethereum/common"
+	bls_core "github.com/harmony-one/bls/ffi/go/bls"
+	"github.com/harmony-one/harmony/consensus/votepower"
+	"github.com/harmony-one/harmony/crypto/bls"
+	shardingconfig "github.com/harmony-one/harmony/internal/configs/sharding"
+	"github.com/harmony-one/harmony/multibls"
+	"github.com/harmony-one/harmony/numeric"
+	"github.com/harmony-one/harmony/shard"
+)
+
+var _ Decider = threadSafeDeciderImpl{}
+
+type threadSafeDeciderImpl struct {
+	mu      *sync.RWMutex
+	decider Decider
+}
+
+func NewThreadSafeDecider(decider Decider, mu *sync.RWMutex) Decider {
+	return threadSafeDeciderImpl{
+		mu:      mu,
+		decider: decider,
+	}
+}
+
+func (a threadSafeDeciderImpl) String() string {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.String()
+}
+
+func (a threadSafeDeciderImpl) Participants() multibls.PublicKeys {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.Participants()
+}
+
+func (a threadSafeDeciderImpl) IndexOf(key bls.SerializedPublicKey) int {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.IndexOf(key)
+}
+
+func (a threadSafeDeciderImpl) ParticipantsCount() int64 {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.ParticipantsCount()
+}
+
+func (a threadSafeDeciderImpl) NthNextValidator(slotList shard.SlotList, pubKey *bls.PublicKeyWrapper, next int) (bool, *bls.PublicKeyWrapper) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.NthNextValidator(slotList, pubKey, next)
+}
+
+func (a threadSafeDeciderImpl) NthNextHmy(instance shardingconfig.Instance, pubkey *bls.PublicKeyWrapper, next int) (bool, *bls.PublicKeyWrapper) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.NthNextHmy(instance, pubkey, next)
+}
+
+func (a threadSafeDeciderImpl) NthNextHmyExt(instance shardingconfig.Instance, wrapper *bls.PublicKeyWrapper, i int) (bool, *bls.PublicKeyWrapper) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.NthNextHmyExt(instance, wrapper, i)
+}
+
+func (a threadSafeDeciderImpl) FirstParticipant(instance shardingconfig.Instance) *bls.PublicKeyWrapper {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.FirstParticipant(instance)
+}
+
+func (a threadSafeDeciderImpl) UpdateParticipants(pubKeys, allowlist []bls.PublicKeyWrapper) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	a.decider.UpdateParticipants(pubKeys, allowlist)
+}
+
+func (a threadSafeDeciderImpl) submitVote(p Phase, pubkeys []bls.SerializedPublicKey, sig *bls_core.Sign, headerHash common.Hash, height, viewID uint64) (*votepower.Ballot, error) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.submitVote(p, pubkeys, sig, headerHash, height, viewID)
+}
+
+func (a threadSafeDeciderImpl) SignersCount(phase Phase) int64 {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.SignersCount(phase)
+}
+
+func (a threadSafeDeciderImpl) reset(phases []Phase) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	a.decider.reset(phases)
+}
+
+func (a threadSafeDeciderImpl) ReadBallot(p Phase, pubkey bls.SerializedPublicKey) *votepower.Ballot {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.ReadBallot(p, pubkey)
+}
+
+func (a threadSafeDeciderImpl) TwoThirdsSignersCount() int64 {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.TwoThirdsSignersCount()
+}
+
+func (a threadSafeDeciderImpl) AggregateVotes(p Phase) *bls_core.Sign {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.AggregateVotes(p)
+}
+
+func (a threadSafeDeciderImpl) SetVoters(subCommittee *shard.Committee, epoch *big.Int) (*TallyResult, error) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.SetVoters(subCommittee, epoch)
+}
+
+func (a threadSafeDeciderImpl) Policy() Policy {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.Policy()
+}
+
+func (a threadSafeDeciderImpl) AddNewVote(p Phase, pubkeys []*bls.PublicKeyWrapper, sig *bls_core.Sign, headerHash common.Hash, height, viewID uint64) (*votepower.Ballot, error) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.AddNewVote(p, pubkeys, sig, headerHash, height, viewID)
+}
+
+func (a threadSafeDeciderImpl) IsQuorumAchievedByMask(mask *bls.Mask) bool {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.IsQuorumAchievedByMask(mask)
+}
+
+func (a threadSafeDeciderImpl) QuorumThreshold() numeric.Dec {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.QuorumThreshold()
+}
+
+func (a threadSafeDeciderImpl) IsAllSigsCollected() bool {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.IsAllSigsCollected()
+}
+
+func (a threadSafeDeciderImpl) ResetPrepareAndCommitVotes() {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	a.decider.ResetPrepareAndCommitVotes()
+}
+
+func (a threadSafeDeciderImpl) ResetViewChangeVotes() {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	a.decider.ResetViewChangeVotes()
+}
+
+func (a threadSafeDeciderImpl) CurrentTotalPower(p Phase) (*numeric.Dec, error) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.CurrentTotalPower(p)
+}
+
+func (a threadSafeDeciderImpl) IsQuorumAchieved(p Phase) bool {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.decider.IsQuorumAchieved(p)
+}
diff --git a/consensus/threshold.go b/consensus/threshold.go
index e611eaedc..339f6d2a7 100644
--- a/consensus/threshold.go
+++ b/consensus/threshold.go
@@ -57,7 +57,7 @@ func (consensus *Consensus) didReachPrepareQuorum() error {
 			continue
 		}
 
-		if _, err := consensus.Decider.AddNewVote(
+		if _, err := consensus.decider.AddNewVote(
 			quorum.Commit,
 			[]*bls.PublicKeyWrapper{key.Pub},
 			key.Pri.SignHash(commitPayload),
diff --git a/consensus/validator.go b/consensus/validator.go
index 891fe0c03..fa5cdac92 100644
--- a/consensus/validator.go
+++ b/consensus/validator.go
@@ -199,12 +199,12 @@ func (consensus *Consensus) onPrepared(recvMsg *FBFTMessage) {
 
 	// check validity of prepared signature
 	blockHash := recvMsg.BlockHash
-	aggSig, mask, err := consensus.readSignatureBitmapPayload(recvMsg.Payload, 0, consensus.Decider.Participants())
+	aggSig, mask, err := consensus.readSignatureBitmapPayload(recvMsg.Payload, 0, consensus.decider.Participants())
 	if err != nil {
 		consensus.getLogger().Error().Err(err).Msg("ReadSignatureBitmapPayload failed!")
 		return
 	}
-	if !consensus.Decider.IsQuorumAchievedByMask(mask) {
+	if !consensus.decider.IsQuorumAchievedByMask(mask) {
 		consensus.getLogger().Warn().Msgf("[OnPrepared] Quorum Not achieved.")
 		return
 	}
@@ -335,7 +335,7 @@ func (consensus *Consensus) onCommitted(recvMsg *FBFTMessage) {
 		return
 	}
 
-	aggSig, mask, err := chain.DecodeSigBitmap(sigBytes, bitmap, consensus.Decider.Participants())
+	aggSig, mask, err := chain.DecodeSigBitmap(sigBytes, bitmap, consensus.decider.Participants())
 	if err != nil {
 		consensus.getLogger().Error().Err(err).Msg("[OnCommitted] readSignatureBitmapPayload failed")
 		return
diff --git a/consensus/view_change.go b/consensus/view_change.go
index d03ae5a13..1171b073e 100644
--- a/consensus/view_change.go
+++ b/consensus/view_change.go
@@ -187,7 +187,7 @@ func (consensus *Consensus) getNextLeaderKey(viewID uint64, committee *shard.Com
 			// it can still sync with other validators.
 			if curHeader.IsLastBlockInEpoch() {
 				consensus.getLogger().Info().Msg("[getNextLeaderKey] view change in the first block of new epoch")
-				lastLeaderPubKey = consensus.Decider.FirstParticipant(shard.Schedule.InstanceForEpoch(epoch))
+				lastLeaderPubKey = consensus.decider.FirstParticipant(shard.Schedule.InstanceForEpoch(epoch))
 			}
 		}
 	}
@@ -204,18 +204,18 @@ func (consensus *Consensus) getNextLeaderKey(viewID uint64, committee *shard.Com
 	var next *bls.PublicKeyWrapper
 	if blockchain != nil && blockchain.Config().IsLeaderRotationInternalValidators(epoch) {
 		if blockchain.Config().IsLeaderRotationExternalValidatorsAllowed(epoch) {
-			wasFound, next = consensus.Decider.NthNextValidator(
+			wasFound, next = consensus.decider.NthNextValidator(
 				committee.Slots,
 				lastLeaderPubKey,
 				gap)
 		} else {
-			wasFound, next = consensus.Decider.NthNextHmy(
+			wasFound, next = consensus.decider.NthNextHmy(
 				shard.Schedule.InstanceForEpoch(epoch),
 				lastLeaderPubKey,
 				gap)
 		}
 	} else {
-		wasFound, next = consensus.Decider.NthNextHmy(
+		wasFound, next = consensus.decider.NthNextHmy(
 			shard.Schedule.InstanceForEpoch(epoch),
 			lastLeaderPubKey,
 			gap)
@@ -281,7 +281,7 @@ func (consensus *Consensus) startViewChange() {
 	defer consensus.consensusTimeout[timeoutViewChange].Start()
 
 	// update the dictionary key if the viewID is first time received
-	members := consensus.Decider.Participants()
+	members := consensus.decider.Participants()
 	consensus.vc.AddViewIDKeyIfNotExist(nextViewID, members)
 
 	// init my own payload
@@ -386,10 +386,10 @@ func (consensus *Consensus) onViewChange(recvMsg *FBFTMessage) {
 		return
 	}
 
-	if consensus.Decider.IsQuorumAchievedByMask(consensus.vc.GetViewIDBitmap(recvMsg.ViewID)) {
+	if consensus.decider.IsQuorumAchievedByMask(consensus.vc.GetViewIDBitmap(recvMsg.ViewID)) {
 		consensus.getLogger().Info().
-			Int64("have", consensus.Decider.SignersCount(quorum.ViewChange)).
-			Int64("need", consensus.Decider.TwoThirdsSignersCount()).
+			Int64("have", consensus.decider.SignersCount(quorum.ViewChange)).
+			Int64("need", consensus.decider.TwoThirdsSignersCount()).
 			Interface("SenderPubkeys", recvMsg.SenderPubkeys).
 			Str("newLeaderKey", newLeaderKey.Bytes.Hex()).
 			Msg("[onViewChange] Received Enough View Change Messages")
@@ -404,7 +404,7 @@ func (consensus *Consensus) onViewChange(recvMsg *FBFTMessage) {
 	senderKey := recvMsg.SenderPubkeys[0]
 
 	// update the dictionary key if the viewID is first time received
-	members := consensus.Decider.Participants()
+	members := consensus.decider.Participants()
 	consensus.vc.AddViewIDKeyIfNotExist(recvMsg.ViewID, members)
 
 	// do it once only per viewID/Leader
@@ -420,7 +420,7 @@ func (consensus *Consensus) onViewChange(recvMsg *FBFTMessage) {
 		return
 	}
 
-	err = consensus.vc.ProcessViewChangeMsg(consensus.fBFTLog, consensus.Decider, recvMsg, consensus.verifyBlock)
+	err = consensus.vc.ProcessViewChangeMsg(consensus.fBFTLog, consensus.decider, recvMsg, consensus.verifyBlock)
 	if err != nil {
 		consensus.getLogger().Error().Err(err).
 			Uint64("viewID", recvMsg.ViewID).
@@ -431,7 +431,7 @@ func (consensus *Consensus) onViewChange(recvMsg *FBFTMessage) {
 	}
 
 	// received enough view change messages, change state to normal consensus
-	if consensus.Decider.IsQuorumAchievedByMask(consensus.vc.GetViewIDBitmap(recvMsg.ViewID)) && consensus.isViewChangingMode() {
+	if consensus.decider.IsQuorumAchievedByMask(consensus.vc.GetViewIDBitmap(recvMsg.ViewID)) && consensus.isViewChangingMode() {
 		// no previous prepared message, go straight to normal mode
 		// and start proposing new block
 		if consensus.vc.IsM1PayloadEmpty() {
@@ -495,7 +495,7 @@ func (consensus *Consensus) onNewView(recvMsg *FBFTMessage) {
 	}
 
 	m3Mask := recvMsg.M3Bitmap
-	if !consensus.Decider.IsQuorumAchievedByMask(m3Mask) {
+	if !consensus.decider.IsQuorumAchievedByMask(m3Mask) {
 		consensus.getLogger().Warn().
 			Msgf("[onNewView] Quorum Not achieved")
 		return
@@ -507,7 +507,7 @@ func (consensus *Consensus) onNewView(recvMsg *FBFTMessage) {
 			utils.CountOneBits(m3Mask.Bitmap) > utils.CountOneBits(m2Mask.Bitmap)) {
 		// m1 is not empty, check it's valid
 		blockHash := recvMsg.Payload[:32]
-		aggSig, mask, err := consensus.readSignatureBitmapPayload(recvMsg.Payload, 32, consensus.Decider.Participants())
+		aggSig, mask, err := consensus.readSignatureBitmapPayload(recvMsg.Payload, 32, consensus.decider.Participants())
 		if err != nil {
 			consensus.getLogger().Error().Err(err).
 				Msg("[onNewView] ReadSignatureBitmapPayload Failed")
@@ -584,5 +584,5 @@ func (consensus *Consensus) resetViewChangeState() {
 		Msg("[ResetViewChangeState] Resetting view change state")
 	consensus.current.SetMode(Normal)
 	consensus.vc.Reset()
-	consensus.Decider.ResetViewChangeVotes()
+	consensus.decider.ResetViewChangeVotes()
 }
diff --git a/consensus/view_change_test.go b/consensus/view_change_test.go
index 96d8fbc86..bbc699944 100644
--- a/consensus/view_change_test.go
+++ b/consensus/view_change_test.go
@@ -94,7 +94,7 @@ func TestGetNextLeaderKeyShouldSucceed(t *testing.T) {
 	_, _, consensus, _, err := GenerateConsensusForTesting()
 	assert.NoError(t, err)
 
-	assert.Equal(t, int64(0), consensus.Decider.ParticipantsCount())
+	assert.Equal(t, int64(0), consensus.Decider().ParticipantsCount())
 
 	blsKeys := []*bls_core.PublicKey{}
 	wrappedBLSKeys := []bls.PublicKeyWrapper{}
@@ -111,8 +111,8 @@ func TestGetNextLeaderKeyShouldSucceed(t *testing.T) {
 		wrappedBLSKeys = append(wrappedBLSKeys, wrapped)
 	}
 
-	consensus.Decider.UpdateParticipants(wrappedBLSKeys, []bls.PublicKeyWrapper{})
-	assert.Equal(t, keyCount, consensus.Decider.ParticipantsCount())
+	consensus.Decider().UpdateParticipants(wrappedBLSKeys, []bls.PublicKeyWrapper{})
+	assert.Equal(t, keyCount, consensus.Decider().ParticipantsCount())
 
 	consensus.LeaderPubKey = &wrappedBLSKeys[0]
 	nextKey := consensus.getNextLeaderKey(uint64(1), nil)
diff --git a/node/api.go b/node/api.go
index ef76079f1..e3862f510 100644
--- a/node/api.go
+++ b/node/api.go
@@ -177,7 +177,7 @@ func (node *Node) GetConfig() rpc_common.Config {
 
 // GetLastSigningPower get last signed power
 func (node *Node) GetLastSigningPower() (float64, error) {
-	power, err := node.Consensus.Decider.CurrentTotalPower(quorum.Commit)
+	power, err := node.Consensus.Decider().CurrentTotalPower(quorum.Commit)
 	if err != nil {
 		return 0, err
 	}
diff --git a/node/node.go b/node/node.go
index df766e52e..d815f86ec 100644
--- a/node/node.go
+++ b/node/node.go
@@ -655,7 +655,7 @@ func validateShardBoundMessage(consensus *consensus.Consensus, peer libp2p_peer.
 			return nil, nil, true, errors.WithStack(shard.ErrValidNotInCommittee)
 		}
 	} else {
-		count := consensus.Decider.ParticipantsCount()
+		count := consensus.Decider().ParticipantsCount()
 		if (count+7)>>3 != int64(len(senderBitmap)) {
 			nodeConsensusMessageCounterVec.With(prometheus.Labels{"type": "invalid_participant_count"}).Inc()
 			return nil, nil, true, errors.WithStack(errWrongSizeOfBitmap)
diff --git a/node/node_explorer.go b/node/node_explorer.go
index ce1b0a244..1e4a4010a 100644
--- a/node/node_explorer.go
+++ b/node/node_explorer.go
@@ -53,7 +53,7 @@ func (node *Node) explorerMessageHandler(ctx context.Context, msg *msg_pb.Messag
 			return err
 		}
 
-		if !node.Consensus.Decider.IsQuorumAchievedByMask(mask) {
+		if !node.Consensus.Decider().IsQuorumAchievedByMask(mask) {
 			utils.Logger().Error().Msg("[Explorer] not have enough signature power")
 			return nil
 		}