diff --git a/cmd/substitute_server/substitute.go b/cmd/substitute_server/substitute.go
index d669aad..4ee0366 100644
--- a/cmd/substitute_server/substitute.go
+++ b/cmd/substitute_server/substitute.go
@@ -377,8 +377,8 @@ func (c *Client) encryptionResponse() ([]byte, []byte, error) {
 	}
 
 	var (
-		SharedSecret ByteArray
-		VerifyToken  ByteArray
+		SharedSecret pk.ByteArray
+		VerifyToken  pk.ByteArray
 	)
 	if err := p.Scan(&SharedSecret, &VerifyToken); err != nil {
 		return nil, nil, err
@@ -386,20 +386,6 @@ func (c *Client) encryptionResponse() ([]byte, []byte, error) {
 	return SharedSecret, VerifyToken, nil
 }
 
-//ByteArray is []byte with perfix VarInt as length
-type ByteArray []byte
-
-// Decode a ByteArray
-func (b *ByteArray) Decode(r pk.DecodeReader) error {
-	var Len pk.VarInt
-	if err := Len.Decode(r); err != nil {
-		return err
-	}
-	*b = make([]byte, Len)
-	_, err := r.Read(*b)
-	return err
-}
-
 type authResp struct {
 	ID, Name   string
 	Properties [1]struct {
diff --git a/net/packet/packet_test.go b/net/packet/packet_test.go
index 63a0ab0..e3fd953 100644
--- a/net/packet/packet_test.go
+++ b/net/packet/packet_test.go
@@ -19,7 +19,7 @@ var PackedVarInts = [][]byte{
 	[]byte{0x80, 0x80, 0x80, 0x80, 0x08},
 }
 
-func TestPackInt(t *testing.T) {
+func TestPackVarInt(t *testing.T) {
 	for i, v := range VarInts {
 		p := v.Encode()
 		if !bytes.Equal(p, PackedVarInts[i]) {
@@ -27,7 +27,7 @@ func TestPackInt(t *testing.T) {
 		}
 	}
 }
-func TestUnpackInt(t *testing.T) {
+func TestUnpackVarInt(t *testing.T) {
 	for i, v := range PackedVarInts {
 		var vi VarInt
 		if err := vi.Decode(bytes.NewReader(v)); err != nil {
diff --git a/net/packet/types.go b/net/packet/types.go
index d3e583f..3dcdeed 100644
--- a/net/packet/types.go
+++ b/net/packet/types.go
@@ -76,6 +76,9 @@ type (
 	NBT struct {
 		V interface{}
 	}
+
+	//ByteArray is []byte with perfix VarInt as length
+	ByteArray []byte
 )
 
 //ReadNBytes read N bytes from bytes.Reader
@@ -354,3 +357,19 @@ func (d *Double) Decode(r DecodeReader) error {
 func (n NBT) Decode(r DecodeReader) error {
 	return nbt.NewDecoder(r).Decode(n.V)
 }
+
+// Encode a ByteArray
+func (b *ByteArray) Encode() []byte {
+	return append(VarInt(len(*b)).Encode(), *b...)
+}
+
+// Decode a ByteArray
+func (b *ByteArray) Decode(r DecodeReader) error {
+	var Len VarInt
+	if err := Len.Decode(r); err != nil {
+		return err
+	}
+	*b = make([]byte, Len)
+	_, err := r.Read(*b)
+	return err
+}