diff --git a/aws-code/transaction_generator.go b/aws-code/transaction_generator.go
index 9875023d9..bdec538b5 100644
--- a/aws-code/transaction_generator.go
+++ b/aws-code/transaction_generator.go
@@ -51,7 +51,7 @@ func getNewFakeTransactions(dataNode *node.Node, numTxs int) []*blockchain.Trans
 				countAll++
 				if rand.Intn(100) < 50 { // 50% sample rate to select UTXO to use for new transactions
 					// Spend the money of current UTXO to a random address in [1 - 1000]
-					txin := blockchain.TXInput{txId, index, address}
+					txin := blockchain.TXInput{txId, index, address, dataNode.Consensus.ShardID}
 					txout := blockchain.TXOutput{value, strconv.Itoa(rand.Intn(10000))}
 					tx := blockchain.Transaction{[32]byte{}, []blockchain.TXInput{txin}, []blockchain.TXOutput{txout}}
 					tx.SetID()
diff --git a/blockchain/block.go b/blockchain/block.go
index a0d7e8e6e..1eb6e550d 100644
--- a/blockchain/block.go
+++ b/blockchain/block.go
@@ -18,7 +18,7 @@ type Block struct {
 	NumTransactions int32
 	TransactionIds  [][32]byte
 	Transactions    []*Transaction // Transactions
-
+	ShardId         uint32
 	// Signature...
 }
 
@@ -68,20 +68,20 @@ func (b *Block) HashTransactions() []byte {
 }
 
 // NewBlock creates and returns a neew block.
-func NewBlock(transactions []*Transaction, prevBlockHash [32]byte) *Block {
+func NewBlock(transactions []*Transaction, prevBlockHash [32]byte, shardId uint32) *Block {
 	numTxs := int32(len(transactions))
 	var txIds [][32]byte
 
 	for _, tx := range transactions {
 		txIds = append(txIds, tx.ID)
 	}
-	block := &Block{time.Now().Unix(), prevBlockHash, [32]byte{}, numTxs, txIds, transactions}
+	block := &Block{time.Now().Unix(), prevBlockHash, [32]byte{}, numTxs, txIds, transactions, shardId}
 	copy(block.Hash[:], block.HashTransactions()[:]) // TODO(Minh): the blockhash should be a hash of everything in the block
 
 	return block
 }
 
 // NewGenesisBlock creates and returns genesis Block.
-func NewGenesisBlock(coinbase *Transaction) *Block {
-	return NewBlock([]*Transaction{coinbase}, [32]byte{})
+func NewGenesisBlock(coinbase *Transaction, shardId uint32) *Block {
+	return NewBlock([]*Transaction{coinbase}, [32]byte{}, shardId)
 }
diff --git a/blockchain/block_test.go b/blockchain/block_test.go
index 2566cfcdd..e60d14362 100644
--- a/blockchain/block_test.go
+++ b/blockchain/block_test.go
@@ -6,11 +6,11 @@ import (
 )
 
 func TestBlockSerialize(t *testing.T) {
-	cbtx := NewCoinbaseTX("minh", genesisCoinbaseData)
+	cbtx := NewCoinbaseTX("minh", genesisCoinbaseData, 0)
 	if cbtx == nil {
 		t.Errorf("Failed to create a coinbase transaction.")
 	}
-	block := NewGenesisBlock(cbtx)
+	block := NewGenesisBlock(cbtx, 0)
 
 	serializedValue := block.Serialize()
 	deserializedBlock := DeserializeBlock(serializedValue)
diff --git a/blockchain/blockchain.go b/blockchain/blockchain.go
index 9dcc145e4..e2a986f43 100644
--- a/blockchain/blockchain.go
+++ b/blockchain/blockchain.go
@@ -103,7 +103,7 @@ Work:
 }
 
 // NewUTXOTransaction creates a new transaction
-func (bc *Blockchain) NewUTXOTransaction(from, to string, amount int) *Transaction {
+func (bc *Blockchain) NewUTXOTransaction(from, to string, amount int, shardId uint32) *Transaction {
 	var inputs []TXInput
 	var outputs []TXOutput
 
@@ -121,7 +121,7 @@ func (bc *Blockchain) NewUTXOTransaction(from, to string, amount int) *Transacti
 		}
 
 		for _, out := range outs {
-			input := TXInput{txID, out, from}
+			input := TXInput{txID, out, from, shardId}
 			inputs = append(inputs, input)
 		}
 	}
@@ -140,10 +140,10 @@ func (bc *Blockchain) NewUTXOTransaction(from, to string, amount int) *Transacti
 
 // AddNewUserTransfer creates a new transaction and a block of that transaction.
 // Mostly used for testing.
-func (bc *Blockchain) AddNewUserTransfer(utxoPool *UTXOPool, from, to string, amount int) bool {
-	tx := bc.NewUTXOTransaction(from, to, amount)
+func (bc *Blockchain) AddNewUserTransfer(utxoPool *UTXOPool, from, to string, amount int, shardId uint32) bool {
+	tx := bc.NewUTXOTransaction(from, to, amount, shardId)
 	if tx != nil {
-		newBlock := NewBlock([]*Transaction{tx}, bc.Blocks[len(bc.Blocks)-1].Hash)
+		newBlock := NewBlock([]*Transaction{tx}, bc.Blocks[len(bc.Blocks)-1].Hash, shardId)
 		if bc.VerifyNewBlockAndUpdate(utxoPool, newBlock) {
 			return true
 		}
@@ -169,11 +169,11 @@ func (bc *Blockchain) VerifyNewBlockAndUpdate(utxopool *UTXOPool, block *Block)
 }
 
 // CreateBlockchain creates a new blockchain DB
-func CreateBlockchain(address string) *Blockchain {
+func CreateBlockchain(address string, shardId uint32) *Blockchain {
 	// TODO: We assume we have not created any blockchain before.
 	// In current bitcoin, we can check if we created a blockchain before accessing local db.
-	cbtx := NewCoinbaseTX(address, genesisCoinbaseData)
-	genesis := NewGenesisBlock(cbtx)
+	cbtx := NewCoinbaseTX(address, genesisCoinbaseData, shardId)
+	genesis := NewGenesisBlock(cbtx, shardId)
 
 	bc := Blockchain{[]*Block{genesis}}
 
diff --git a/blockchain/blockchain_test.go b/blockchain/blockchain_test.go
index ed7c73652..f0e6f8c57 100644
--- a/blockchain/blockchain_test.go
+++ b/blockchain/blockchain_test.go
@@ -5,14 +5,14 @@ import (
 )
 
 func TestCreateBlockchain(t *testing.T) {
-	if bc := CreateBlockchain("minh"); bc == nil {
+	if bc := CreateBlockchain("minh", 0); bc == nil {
 		t.Errorf("failed to create a blockchain")
 	}
 }
 
 func TestFindSpendableOutputs(t *testing.T) {
 	requestAmount := 3
-	bc := CreateBlockchain("minh")
+	bc := CreateBlockchain("minh", 0)
 	accumulated, unspentOutputs := bc.FindSpendableOutputs("minh", requestAmount)
 	if accumulated < DefaultCoinbaseValue {
 		t.Error("Failed to find enough unspent ouptuts")
@@ -24,7 +24,7 @@ func TestFindSpendableOutputs(t *testing.T) {
 }
 
 func TestFindUTXO(t *testing.T) {
-	bc := CreateBlockchain("minh")
+	bc := CreateBlockchain("minh", 0)
 	utxo := bc.FindUTXO("minh")
 
 	total := 0
@@ -41,34 +41,34 @@ func TestFindUTXO(t *testing.T) {
 }
 
 func TestAddNewUserTransfer(t *testing.T) {
-	bc := CreateBlockchain("minh")
+	bc := CreateBlockchain("minh", 0)
 	utxoPool := CreateUTXOPoolFromGenesisBlockChain(bc)
 
-	if !bc.AddNewUserTransfer(utxoPool, "minh", "alok", 3) {
+	if !bc.AddNewUserTransfer(utxoPool, "minh", "alok", 3, 0) {
 		t.Error("Failed to add new transfer to alok.")
 	}
 
-	if !bc.AddNewUserTransfer(utxoPool, "minh", "rj", 100) {
+	if !bc.AddNewUserTransfer(utxoPool, "minh", "rj", 100, 0) {
 		t.Error("Failed to add new transfer to rj.")
 	}
 
-	if bc.AddNewUserTransfer(utxoPool, "minh", "stephen", DefaultCoinbaseValue-102) {
+	if bc.AddNewUserTransfer(utxoPool, "minh", "stephen", DefaultCoinbaseValue-102, 0) {
 		t.Error("minh should not have enough fun to make the transfer.")
 	}
 }
 
 func TestVerifyNewBlock(t *testing.T) {
-	bc := CreateBlockchain("minh")
+	bc := CreateBlockchain("minh", 0)
 	utxoPool := CreateUTXOPoolFromGenesisBlockChain(bc)
 
-	bc.AddNewUserTransfer(utxoPool, "minh", "alok", 3)
-	bc.AddNewUserTransfer(utxoPool, "minh", "rj", 100)
+	bc.AddNewUserTransfer(utxoPool, "minh", "alok", 3, 0)
+	bc.AddNewUserTransfer(utxoPool, "minh", "rj", 100, 0)
 
-	tx := bc.NewUTXOTransaction("minh", "mark", 10)
+	tx := bc.NewUTXOTransaction("minh", "mark", 10, 0)
 	if tx == nil {
 		t.Error("failed to create a new transaction.")
 	}
-	newBlock := NewBlock([]*Transaction{tx}, bc.Blocks[len(bc.Blocks)-1].Hash)
+	newBlock := NewBlock([]*Transaction{tx}, bc.Blocks[len(bc.Blocks)-1].Hash, 0)
 
 	if !bc.VerifyNewBlockAndUpdate(utxoPool, newBlock) {
 		t.Error("failed to add a new valid block.")
diff --git a/blockchain/transaction.go b/blockchain/transaction.go
index ee38c78fb..f3843113f 100644
--- a/blockchain/transaction.go
+++ b/blockchain/transaction.go
@@ -22,11 +22,12 @@ type TXOutput struct {
 	Address string
 }
 
-// TXInput is the struct of transaction input in a transaction.
+// TXInput is the struct of transaction input (a UTXO) in a transaction.
 type TXInput struct {
 	TxID          []byte
 	TxOutputIndex int
 	Address       string
+	ShardId       uint32 // The Id of the shard where this UTXO belongs
 }
 
 // DefaultCoinbaseValue is the default value of coinbase transaction.
@@ -47,12 +48,12 @@ func (tx *Transaction) SetID() {
 }
 
 // NewCoinbaseTX creates a new coinbase transaction
-func NewCoinbaseTX(to, data string) *Transaction {
+func NewCoinbaseTX(to, data string, shardId uint32) *Transaction {
 	if data == "" {
 		data = fmt.Sprintf("Reward to '%s'", to)
 	}
 
-	txin := TXInput{[]byte{}, -1, data}
+	txin := TXInput{[]byte{}, -1, data, shardId}
 	txout := TXOutput{DefaultCoinbaseValue, to}
 	tx := Transaction{[32]byte{}, []TXInput{txin}, []TXOutput{txout}}
 	tx.SetID()
diff --git a/blockchain/transaction_test.go b/blockchain/transaction_test.go
index 037dd807e..bf693cf86 100644
--- a/blockchain/transaction_test.go
+++ b/blockchain/transaction_test.go
@@ -5,7 +5,7 @@ import (
 )
 
 func TestNewCoinbaseTX(t *testing.T) {
-	if cbtx := NewCoinbaseTX("minh", genesisCoinbaseData); cbtx == nil {
+	if cbtx := NewCoinbaseTX("minh", genesisCoinbaseData, 0); cbtx == nil {
 		t.Errorf("failed to create a coinbase transaction.")
 	}
 }
diff --git a/blockchain/utxopool_test.go b/blockchain/utxopool_test.go
index 84f4e4b42..4973a32e0 100644
--- a/blockchain/utxopool_test.go
+++ b/blockchain/utxopool_test.go
@@ -5,13 +5,13 @@ import (
 )
 
 func TestVerifyOneTransactionAndUpdate(t *testing.T) {
-	bc := CreateBlockchain("minh")
+	bc := CreateBlockchain("minh", 0)
 	utxoPool := CreateUTXOPoolFromGenesisBlockChain(bc)
 
-	bc.AddNewUserTransfer(utxoPool, "minh", "alok", 3)
-	bc.AddNewUserTransfer(utxoPool, "minh", "rj", 100)
+	bc.AddNewUserTransfer(utxoPool, "minh", "alok", 3, 0)
+	bc.AddNewUserTransfer(utxoPool, "minh", "rj", 100, 0)
 
-	tx := bc.NewUTXOTransaction("minh", "mark", 10)
+	tx := bc.NewUTXOTransaction("minh", "mark", 10, 0)
 	if tx == nil {
 		t.Error("failed to create a new transaction.")
 	}
@@ -23,11 +23,11 @@ func TestVerifyOneTransactionAndUpdate(t *testing.T) {
 }
 
 func TestDeleteOneBalanceItem(t *testing.T) {
-	bc := CreateBlockchain("minh")
+	bc := CreateBlockchain("minh", 0)
 	utxoPool := CreateUTXOPoolFromGenesisBlockChain(bc)
 
-	bc.AddNewUserTransfer(utxoPool, "minh", "alok", 3)
-	bc.AddNewUserTransfer(utxoPool, "alok", "rj", 3)
+	bc.AddNewUserTransfer(utxoPool, "minh", "alok", 3, 0)
+	bc.AddNewUserTransfer(utxoPool, "alok", "rj", 3, 0)
 
 	if _, ok := utxoPool.UtxoMap["alok"]; ok {
 		t.Errorf("alok should not be contained in the balance map")
diff --git a/consensus/consensus_leader.go b/consensus/consensus_leader.go
index 23c2ee3bd..b1ab24497 100644
--- a/consensus/consensus_leader.go
+++ b/consensus/consensus_leader.go
@@ -56,8 +56,8 @@ func (consensus *Consensus) ProcessMessageLeader(message []byte) {
 
 // Handler for message which triggers consensus process
 func (consensus *Consensus) processStartConsensusMessage(payload []byte) {
-	tx := blockchain.NewCoinbaseTX("x", "y")
-	consensus.startConsensus(blockchain.NewGenesisBlock(tx))
+	tx := blockchain.NewCoinbaseTX("x", "y", 0)
+	consensus.startConsensus(blockchain.NewGenesisBlock(tx, 0))
 }
 
 func (consensus *Consensus) startConsensus(newBlock *blockchain.Block) {
diff --git a/node/node.go b/node/node.go
index 85987ee2a..24057475a 100644
--- a/node/node.go
+++ b/node/node.go
@@ -15,10 +15,10 @@ var pendingTxMutex = &sync.Mutex{}
 // Node represents a program (machine) participating in the network
 // TODO(minhdoan, rj): consider using BlockChannel *chan blockchain.Block for efficiency.
 type Node struct {
-	consensus              *consensus.Consensus      // Consensus object containing all consensus related data (e.g. committee members, signatures, commits)
+	Consensus              *consensus.Consensus      // Consensus object containing all Consensus related data (e.g. committee members, signatures, commits)
 	BlockChannel           chan blockchain.Block     // The channel to receive new blocks from Node
-	pendingTransactions    []*blockchain.Transaction // All the transactions received but not yet processed for consensus
-	transactionInConsensus []*blockchain.Transaction // The transactions selected into the new block and under consensus process
+	pendingTransactions    []*blockchain.Transaction // All the transactions received but not yet processed for Consensus
+	transactionInConsensus []*blockchain.Transaction // The transactions selected into the new block and under Consensus process
 	blockchain             *blockchain.Blockchain    // The blockchain for the shard where this node belongs
 	UtxoPool               *blockchain.UTXOPool      // The corresponding UTXO pool of the current blockchain
 	log                    log.Logger                // Log utility
@@ -68,7 +68,7 @@ func (node *Node) listenOnPort(port string) {
 }
 
 func (node *Node) String() string {
-	return node.consensus.String()
+	return node.Consensus.String()
 }
 
 // [Testing code] Should be deleted for production
@@ -76,7 +76,7 @@ func (node *Node) String() string {
 func (node *Node) AddMoreFakeTransactions(numTxs int) {
 	txs := make([]*blockchain.Transaction, numTxs)
 	for i := range txs {
-		txs[i] = blockchain.NewCoinbaseTX(strconv.Itoa(i), "")
+		txs[i] = blockchain.NewCoinbaseTX(strconv.Itoa(i), "", node.Consensus.ShardID)
 	}
 	node.blockchain.Blocks[0].Transactions = append(node.blockchain.Blocks[0].Transactions, txs...)
 	node.UtxoPool.Update(txs)
@@ -97,20 +97,20 @@ func NewNode(consensus *consensus.Consensus) Node {
 	node := Node{}
 
 	// Consensus and associated channel to communicate blocks
-	node.consensus = consensus
+	node.Consensus = consensus
 	node.BlockChannel = make(chan blockchain.Block)
 
 	// Genesis Block
 	genesisBlock := &blockchain.Blockchain{}
 	genesisBlock.Blocks = make([]*blockchain.Block, 0)
-	coinbaseTx := blockchain.NewCoinbaseTX("harmony", "1")
-	genesisBlock.Blocks = append(genesisBlock.Blocks, blockchain.NewGenesisBlock(coinbaseTx))
+	coinbaseTx := blockchain.NewCoinbaseTX("harmony", "1", node.Consensus.ShardID)
+	genesisBlock.Blocks = append(genesisBlock.Blocks, blockchain.NewGenesisBlock(coinbaseTx, node.Consensus.ShardID))
 	node.blockchain = genesisBlock
 
 	// UTXO pool from Genesis block
 	node.UtxoPool = blockchain.CreateUTXOPoolFromGenesisBlockChain(node.blockchain)
 
 	// Logger
-	node.log = node.consensus.Log
+	node.log = node.Consensus.Log
 	return node
 }
diff --git a/node/node_handler.go b/node/node_handler.go
index 55c0ace20..84bf8a061 100644
--- a/node/node_handler.go
+++ b/node/node_handler.go
@@ -27,7 +27,7 @@ func (node *Node) NodeHandler(conn net.Conn) {
 		node.log.Error("Read p2p data failed", "err", err, "node", node)
 		return
 	}
-	consensus := node.consensus
+	consensus := node.Consensus
 
 	msgCategory, err := common.GetMessageCategory(content)
 	if err != nil {
@@ -115,11 +115,11 @@ func (node *Node) transactionMessageHandler(msgPayload []byte) {
 
 // WaitForConsensusReady ...
 func (node *Node) WaitForConsensusReady(readySignal chan int) {
-	node.log.Debug("Waiting for consensus ready", "node", node)
+	node.log.Debug("Waiting for Consensus ready", "node", node)
 
 	var newBlock *blockchain.Block
 	timeoutCount := 0
-	for { // keep waiting for consensus ready
+	for { // keep waiting for Consensus ready
 		retry := false
 		select {
 		case <-readySignal:
@@ -142,17 +142,17 @@ func (node *Node) WaitForConsensusReady(readySignal chan int) {
 						node.log.Debug("Creating new block", "numTxs", len(selectedTxs), "pendingTxs", len(node.pendingTransactions), "currentChainSize", len(node.blockchain.Blocks))
 
 						node.transactionInConsensus = selectedTxs
-						newBlock = blockchain.NewBlock(selectedTxs, node.blockchain.GetLatestBlock().Hash)
+						newBlock = blockchain.NewBlock(selectedTxs, node.blockchain.GetLatestBlock().Hash, node.Consensus.ShardID)
 						break
 					}
 				}
-				// If not enough transactions to run consensus,
+				// If not enough transactions to run Consensus,
 				// periodically check whether we have enough transactions to package into block.
 				time.Sleep(1 * time.Second)
 			}
 		}
 
-		// Send the new block to consensus so it can be confirmed.
+		// Send the new block to Consensus so it can be confirmed.
 		if newBlock != nil {
 			node.BlockChannel <- *newBlock
 		}
@@ -168,6 +168,6 @@ func (node *Node) AddNewBlockToBlockchain(newBlock *blockchain.Block) {
 	node.blockchain.Blocks = append(node.blockchain.Blocks, newBlock)
 	// Update UTXO pool
 	node.UtxoPool.Update(newBlock.Transactions)
-	// Clear transaction-in-consensus list
+	// Clear transaction-in-Consensus list
 	node.transactionInConsensus = []*blockchain.Transaction{}
 }
diff --git a/node/node_test.go b/node/node_test.go
index 6a6cc1f78..d24f7cd19 100644
--- a/node/node_test.go
+++ b/node/node_test.go
@@ -12,7 +12,7 @@ func TestNewNewNode(test *testing.T) {
 	consensus := consensus.NewConsensus("1", "2", "0", []p2p.Peer{leader, validator}, leader)
 
 	node := NewNode(&consensus)
-	if node.consensus == nil {
+	if node.Consensus == nil {
 		test.Error("Consensus is not initialized for the node")
 	}