diff --git a/core/tx.go b/core/tx.go
index 4ad4c0d..e329b23 100644
--- a/core/tx.go
+++ b/core/tx.go
@@ -1,25 +1,28 @@
 package core
 
+import "crypto/ecdsa"
+
 type Input struct {
 	TxId  Hash
 	Vout  int // index of the output from the TxId
 	Value uint64
 }
+
 type Output struct {
 	Value uint64
 }
 
 // Tx holds the data structure of a transaction
 type Tx struct {
-	From       Address
-	To         Address
+	From       *ecdsa.PublicKey
+	To         *ecdsa.PublicKey
 	InputCount uint64
 	Inputs     []Input
 	Outputs    []Output
 	Signature  []byte
 }
 
-func NewTx(from, to Address, in []Input, out []Output) *Tx {
+func NewTx(from, to *ecdsa.PublicKey, in []Input, out []Output) *Tx {
 	tx := &Tx{
 		From:       from,
 		To:         to,
diff --git a/core/tx_test.go b/core/tx_test.go
index 5f250f8..e172b09 100644
--- a/core/tx_test.go
+++ b/core/tx_test.go
@@ -7,13 +7,17 @@ import (
 )
 
 func TestTx(t *testing.T) {
-	addr0 := Address(HashBytes([]byte("addr0")))
-	addr1 := Address(HashBytes([]byte("addr1")))
+	privK0, err := NewKey()
+	assert.Nil(t, err)
+	pubK0 := privK0.PublicKey
+	privK1, err := NewKey()
+	assert.Nil(t, err)
+	pubK1 := privK1.PublicKey
 
-	tx := NewTx(addr0, addr1, []Input{}, []Output{})
+	tx := NewTx(&pubK0, &pubK1, []Input{}, []Output{})
 
-	assert.Equal(t, tx.From, addr0)
-	assert.Equal(t, tx.To, addr1)
+	assert.Equal(t, tx.From, &pubK0)
+	assert.Equal(t, tx.To, &pubK1)
 
 	assert.True(t, CheckTx(tx))
 }
diff --git a/node/node.go b/node/node.go
index a960c9f..433fb31 100644
--- a/node/node.go
+++ b/node/node.go
@@ -78,8 +78,8 @@ func (node *Node) NewBlock(txs []core.Tx) *core.Block {
 
 func (node *Node) CreateGenesis() (*core.Block, error) {
 	block := &core.Block{
-		Height:    uint64(0),
-		PrevHash:  core.Hash{},
+		Height:    node.Bc.LastBlock.Height,
+		PrevHash:  node.Bc.LastBlock.Hash,
 		Txs:       []core.Tx{},
 		Miner:     node.Addr,
 		MinerPubK: &node.PrivK.PublicKey,
@@ -93,5 +93,6 @@ func (node *Node) CreateGenesis() (*core.Block, error) {
 	if err != nil {
 		return nil, err
 	}
+	block.CalculateHash()
 	return block, nil
 }
diff --git a/node/node_test.go b/node/node_test.go
index 0f0395f..431a9bb 100644
--- a/node/node_test.go
+++ b/node/node_test.go
@@ -62,9 +62,13 @@ func TestBlockFromPendingTxs(t *testing.T) {
 	node, err := NewNode(privK, bc, true)
 	assert.Nil(t, err)
 
-	addr0 := core.Address(core.HashBytes([]byte("addr0")))
-	addr1 := core.Address(core.HashBytes([]byte("addr1")))
-	tx := core.NewTx(addr0, addr1, []core.Input{}, []core.Output{})
+	privK0, err := core.NewKey()
+	assert.Nil(t, err)
+	pubK0 := privK0.PublicKey
+	privK1, err := core.NewKey()
+	assert.Nil(t, err)
+	pubK1 := privK1.PublicKey
+	tx := core.NewTx(&pubK0, &pubK1, []core.Input{}, []core.Output{})
 	node.AddToPendingTxs(*tx)
 	block, err := node.BlockFromPendingTxs()
 	assert.Nil(t, err)
@@ -87,10 +91,15 @@ func TestBlockFromPendingTxsIteration(t *testing.T) {
 	node, err := NewNode(privK, bc, true)
 	assert.Nil(t, err)
 
-	addr0 := core.Address(core.HashBytes([]byte("addr0")))
-	addr1 := core.Address(core.HashBytes([]byte("addr1")))
+	privK0, err := core.NewKey()
+	assert.Nil(t, err)
+	pubK0 := privK0.PublicKey
+	privK1, err := core.NewKey()
+	assert.Nil(t, err)
+	pubK1 := privK1.PublicKey
+
 	for i := 0; i < 10; i++ {
-		tx := core.NewTx(addr0, addr1, []core.Input{}, []core.Output{})
+		tx := core.NewTx(&pubK0, &pubK1, []core.Input{}, []core.Output{})
 		node.AddToPendingTxs(*tx)
 	}
 	block, err := node.BlockFromPendingTxs()
@@ -98,3 +107,35 @@ func TestBlockFromPendingTxsIteration(t *testing.T) {
 	assert.True(t, core.CheckBlockPoW(block, node.Bc.Difficulty))
 	assert.True(t, node.Bc.VerifyBlock(block))
 }
+
+func TestFromGenesisToTenBlocks(t *testing.T) {
+	dir, err := ioutil.TempDir("", "db")
+	assert.Nil(t, err)
+	db, err := db.New(dir)
+	assert.Nil(t, err)
+
+	privK, err := core.NewKey()
+	assert.Nil(t, err)
+
+	dif := uint64(1)
+	bc := core.NewBlockchain(db, dif)
+	node, err := NewNode(privK, bc, true)
+	assert.Nil(t, err)
+
+	// create the genesis block
+	genesisBlock, err := node.CreateGenesis()
+	assert.Nil(t, err)
+	assert.NotEqual(t, genesisBlock.Signature, core.Signature{})
+	assert.NotEqual(t, genesisBlock.Hash, core.Hash{})
+
+	// add the genesis block into the blockchain
+	err = node.Bc.AddBlock(genesisBlock)
+	assert.Nil(t, err)
+	assert.NotEqual(t, genesisBlock.Hash, core.Hash{})
+	assert.Equal(t, genesisBlock.Hash, node.Bc.LastBlock.Hash)
+
+	// TODO add another block
+	block := node.NewBlock([]core.Tx{})
+	err = node.Bc.AddBlock(block)
+	assert.Nil(t, err)
+}