diff --git a/portalnetwork/state/types.go b/portalnetwork/state/types.go
index f3de06084c62..04401bc1c41c 100644
--- a/portalnetwork/state/types.go
+++ b/portalnetwork/state/types.go
@@ -65,7 +65,7 @@ func (n *Nibbles) Deserialize(dr *codec.DecodingReader) error {
 		return err
 	}
 	flag, first := unpackNibblePair(firstByte)
-	nibbles := make([]byte, 1+2*len(packedNibbles))
+	nibbles := make([]byte, 0, 1+2*len(packedNibbles))
 
 	if flag == 0 {
 		if first != 0 {
@@ -77,10 +77,9 @@ func (n *Nibbles) Deserialize(dr *codec.DecodingReader) error {
 		return fmt.Errorf("nibbles: The highest 4 bits of the first byte must be 0 or 1, but was: %x", flag)
 	}
 
-	for i, b := range packedNibbles {
+	for _, b := range packedNibbles {
 		left, right := unpackNibblePair(b)
-		nibbles[1+2*i] = left
-		nibbles[1+2*i+1] = right
+		nibbles = append(nibbles, left, right)
 	}
 
 	unpackedNibbles, err := FromUnpackedNibbles(nibbles)
@@ -114,3 +113,121 @@ func FromUnpackedNibbles(nibbles []byte) (*Nibbles, error) {
 func unpackNibblePair(pair byte) (byte, byte) {
 	return pair >> 4, pair & 0xf
 }
+
+// test data from
+// https://github.com/ethereum/portal-network-specs/blob/master/state/state-network-test-vectors.md
+type AccountTrieNodeKey struct {
+	Path     Nibbles
+	NodeHash common.Bytes32
+}
+
+func (a *AccountTrieNodeKey) Deserialize(dr *codec.DecodingReader) error {
+	return dr.Container(
+		&a.Path,
+		&a.NodeHash,
+	)
+}
+
+func (a *AccountTrieNodeKey) Serialize(w *codec.EncodingWriter) error {
+	return w.Container(
+		&a.Path,
+		&a.NodeHash,
+	)
+}
+
+func (a *AccountTrieNodeKey) ByteLength(spec *common.Spec) uint64 {
+	return codec.ContainerLength(
+		&a.Path,
+		&a.NodeHash,
+	)
+}
+
+func (a *AccountTrieNodeKey) FixedLength(spec *common.Spec) uint64 {
+	return 0
+}
+
+func (a *AccountTrieNodeKey) HashTreeRoot(spec *common.Spec, hFn tree.HashFn) common.Root {
+	return hFn.HashTreeRoot(
+		&a.Path,
+		&a.NodeHash,
+	)
+}
+
+type ContractStorageTrieNodeKey struct {
+	Address  common.Eth1Address
+	Path     Nibbles
+	NodeHash common.Bytes32
+}
+
+func (c *ContractStorageTrieNodeKey) Deserialize(dr *codec.DecodingReader) error {
+	return dr.Container(
+		&c.Address,
+		&c.Path,
+		&c.NodeHash,
+	)
+}
+
+func (c *ContractStorageTrieNodeKey) Serialize(w *codec.EncodingWriter) error {
+	return w.Container(
+		&c.Address,
+		&c.Path,
+		&c.NodeHash,
+	)
+}
+
+func (c *ContractStorageTrieNodeKey) ByteLength(spec *common.Spec) uint64 {
+	return codec.ContainerLength(
+		&c.Address,
+		&c.Path,
+		&c.NodeHash,
+	)
+}
+
+func (c *ContractStorageTrieNodeKey) FixedLength(spec *common.Spec) uint64 {
+	return 0
+}
+
+func (c *ContractStorageTrieNodeKey) HashTreeRoot(spec *common.Spec, hFn tree.HashFn) common.Root {
+	return hFn.HashTreeRoot(
+		&c.Address,
+		&c.Path,
+		&c.NodeHash,
+	)
+}
+
+type ContractBytecodeKey struct {
+	Address  common.Eth1Address
+	NodeHash common.Bytes32
+}
+
+func (c *ContractBytecodeKey) Deserialize(dr *codec.DecodingReader) error {
+	return dr.FixedLenContainer(
+		&c.Address,
+		&c.NodeHash,
+	)
+}
+
+func (c *ContractBytecodeKey) Serialize(w *codec.EncodingWriter) error {
+	return w.FixedLenContainer(
+		&c.Address,
+		&c.NodeHash,
+	)
+}
+
+func (c *ContractBytecodeKey) ByteLength(spec *common.Spec) uint64 {
+	return codec.ContainerLength(
+		&c.Address,
+		&c.NodeHash,
+	)
+}
+
+func (c *ContractBytecodeKey) FixedLength(spec *common.Spec) uint64 {
+	return 0
+}
+
+func (c *ContractBytecodeKey) HashTreeRoot(spec *common.Spec, hFn tree.HashFn) common.Root {
+	return hFn.HashTreeRoot(
+		&c.Address,
+		&c.NodeHash,
+	)
+}
diff --git a/portalnetwork/state/types_test.go b/portalnetwork/state/types_test.go
index 66b3890bb8e3..b40198378743 100644
--- a/portalnetwork/state/types_test.go
+++ b/portalnetwork/state/types_test.go
@@ -5,8 +5,10 @@ import (
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/protolambda/zrnt/eth2/beacon/common"
 	"github.com/protolambda/ztyp/codec"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestNibblesEncodeDecode(t *testing.T) {
@@ -80,6 +82,11 @@ func TestNibblesEncodeDecode(t *testing.T) {
 			err = n.Serialize(codec.NewEncodingWriter(&tt.args.buf))
 			assert.NoError(t, err)
 			assert.Equal(t, tt.encodeds, hexutil.Encode(tt.args.buf.Bytes()))
+
+			newNibble := &Nibbles{}
+			err = newNibble.Deserialize(codec.NewDecodingReader(&tt.args.buf, uint64(len(tt.args.buf.Bytes()))))
+			require.NoError(t, err)
+			require.Equal(t, newNibble.Nibbles, n.Nibbles)
 		})
 	}
 }
@@ -196,3 +203,66 @@ func initSlice(n int, v byte) []byte {
 	}
 	return s
 }
+
+func TestAccountTrieNode(t *testing.T) {
+	n, err := FromUnpackedNibbles([]byte{8, 6, 7, 9, 14, 8, 14, 13})
+	require.NoError(t, err)
+
+	accountTrieNode := &AccountTrieNodeKey{
+		Path:     *n,
+		NodeHash: common.Bytes32(hexutil.MustDecode("0x6225fcc63b22b80301d9f2582014e450e91f9b329b7cc87ad16894722fff5296")),
+	}
+	var buf bytes.Buffer
+	err = accountTrieNode.Serialize(codec.NewEncodingWriter(&buf))
+	require.NoError(t, err)
+	hexStr := hexutil.Encode(buf.Bytes())
+	require.Equal(t, hexStr, "0x240000006225fcc63b22b80301d9f2582014e450e91f9b329b7cc87ad16894722fff5296008679e8ed")
+
+	newAccount := &AccountTrieNodeKey{}
+	err = newAccount.Deserialize(codec.NewDecodingReader(&buf, uint64(len(buf.Bytes()))))
+	require.NoError(t, err)
+	require.Equal(t, newAccount.NodeHash, accountTrieNode.NodeHash)
+	require.Equal(t, newAccount.Path.Nibbles, accountTrieNode.Path.Nibbles)
+}
+
+func TestContractStorageTrieNode(t *testing.T) {
+	path, err := FromUnpackedNibbles([]byte{4, 0, 5, 7, 8, 7})
+	require.NoError(t, err)
+	contractStorage := &ContractStorageTrieNodeKey{
+		Address:  common.Eth1Address(hexutil.MustDecode("0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2")),
+		Path:     *path,
+		NodeHash: common.Bytes32(hexutil.MustDecode("0xeb43d68008d216e753fef198cf51077f5a89f406d9c244119d1643f0f2b19011")),
+	}
+
+	var buf bytes.Buffer
+	err = contractStorage.Serialize(codec.NewEncodingWriter(&buf))
+	require.NoError(t, err)
+	hexStr := hexutil.Encode(buf.Bytes())
+	require.Equal(t, hexStr, "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc238000000eb43d68008d216e753fef198cf51077f5a89f406d9c244119d1643f0f2b1901100405787")
+
+	newContractStorage := &ContractStorageTrieNodeKey{}
+	err = newContractStorage.Deserialize(codec.NewDecodingReader(&buf, uint64(len(buf.Bytes()))))
+	require.NoError(t, err)
+	require.Equal(t, newContractStorage.NodeHash, contractStorage.NodeHash)
+	require.Equal(t, newContractStorage.Path.Nibbles, contractStorage.Path.Nibbles)
+	require.Equal(t, newContractStorage.Address, contractStorage.Address)
+}
+
+func TestContractBytecode(t *testing.T) {
+	bytecode := &ContractBytecodeKey{
+		Address:  common.Eth1Address(hexutil.MustDecode("0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2")),
+		NodeHash: common.Bytes32(hexutil.MustDecode("0xd0a06b12ac47863b5c7be4185c2deaad1c61557033f56c7d4ea74429cbb25e23")),
+	}
+
+	var buf bytes.Buffer
+	err := bytecode.Serialize(codec.NewEncodingWriter(&buf))
+	require.NoError(t, err)
+	hexStr := hexutil.Encode(buf.Bytes())
+	require.Equal(t, hexStr, "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2d0a06b12ac47863b5c7be4185c2deaad1c61557033f56c7d4ea74429cbb25e23")
+
+	newBytecode := &ContractBytecodeKey{}
+	err = newBytecode.Deserialize(codec.NewDecodingReader(&buf, uint64(len(buf.Bytes()))))
+	require.NoError(t, err)
+	require.Equal(t, newBytecode.NodeHash, bytecode.NodeHash)
+	require.Equal(t, newBytecode.Address, bytecode.Address)
+}