diff --git a/constant/intent.go b/constant/intent.go
new file mode 100644
index 0000000..387e6da
--- /dev/null
+++ b/constant/intent.go
@@ -0,0 +1,10 @@
+package constant
+
+type IntentScope = uint8
+
+const (
+	TransactionDataIntentScope    IntentScope = 0
+	TransactionEffectsIntentScope IntentScope = 1
+	CheckpointSummaryIntentScope  IntentScope = 2
+	PersonalMessageIntentScope    IntentScope = 3
+)
diff --git a/models/intent.go b/models/intent.go
new file mode 100644
index 0000000..862cc48
--- /dev/null
+++ b/models/intent.go
@@ -0,0 +1,27 @@
+package models
+
+import "github.com/block-vision/sui-go-sdk/constant"
+
+type AppId int
+
+const (
+	Sui AppId = 0
+)
+
+type IntentVersion int
+
+const (
+	V0 IntentVersion = 0
+)
+
+func IntentWithScope(intentScope constant.IntentScope) []int {
+	return []int{int(intentScope), int(V0), int(Sui)}
+}
+
+func NewMessageWithIntent(message []byte, scope constant.IntentScope) []byte {
+	intent := []byte{scope, 0, 0}
+	intentMessage := make([]byte, len(intent)+len(message))
+	copy(intentMessage, intent)
+	copy(intentMessage[len(intent):], message)
+	return intentMessage
+}
diff --git a/models/signature.go b/models/signature.go
index a5ec43a..fcd5c04 100644
--- a/models/signature.go
+++ b/models/signature.go
@@ -5,9 +5,13 @@ import (
 	"crypto/ed25519"
 	"encoding/base64"
 	"encoding/hex"
-	"golang.org/x/crypto/blake2b"
+	"fmt"
 	"log"
 	"strings"
+
+	"github.com/block-vision/sui-go-sdk/constant"
+
+	"golang.org/x/crypto/blake2b"
 )
 
 type InputObjectKind map[string]interface{}
@@ -38,6 +42,12 @@ type HexData struct {
 	data []byte
 }
 
+type SignaturePubkeyPair struct {
+	SignatureScheme string
+	Signature       []byte
+	PubKey          []byte
+}
+
 func NewHexData(str string) (*HexData, error) {
 	if strings.HasPrefix(str, "0x") || strings.HasPrefix(str, "0X") {
 		str = str[2:]
@@ -113,7 +123,7 @@ func (txn *TxnMetaData) SignSerializedSigWith(privateKey ed25519.PrivateKey) *Si
 	}
 	return &SignedTransactionSerializedSig{
 		TxBytes:   txn.TxBytes,
-		Signature: toSerializedSignature(sigBytes, privateKey.Public().(ed25519.PublicKey)),
+		Signature: ToSerializedSignature(sigBytes, privateKey.Public().(ed25519.PublicKey)),
 	}
 }
 
@@ -125,7 +135,7 @@ func messageWithIntent(message []byte) []byte {
 	return intentMessage
 }
 
-func toSerializedSignature(signature, pubKey []byte) string {
+func ToSerializedSignature(signature, pubKey []byte) string {
 	signatureLen := len(signature)
 	pubKeyLen := len(pubKey)
 	serializedSignature := make([]byte, 1+signatureLen+pubKeyLen)
@@ -134,3 +144,76 @@ func toSerializedSignature(signature, pubKey []byte) string {
 	copy(serializedSignature[1+signatureLen:], pubKey)
 	return base64.StdEncoding.EncodeToString(serializedSignature)
 }
+
+func FromSerializedSignature(serializedSignature string) (*SignaturePubkeyPair, error) {
+	_bytes, err := base64.StdEncoding.DecodeString(serializedSignature)
+	if err != nil {
+		return nil, err
+	}
+	signatureScheme := parseSignatureScheme(_bytes[0])
+	if strings.EqualFold(serializedSignature, "") {
+		return nil, fmt.Errorf("multiSig is not supported")
+	}
+
+	signature := _bytes[1 : len(_bytes)-32]
+	pubKeyBytes := _bytes[1+len(signature):]
+
+	keyPair := &SignaturePubkeyPair{
+		SignatureScheme: signatureScheme,
+		Signature:       signature,
+		PubKey:          pubKeyBytes,
+	}
+	return keyPair, nil
+}
+
+func parseSignatureScheme(scheme byte) string {
+	switch scheme {
+	case 0:
+		return "ED25519"
+	case 1:
+		return "Secp256k1"
+	case 2:
+		return "Secp256r1"
+	case 3:
+		return "MultiSig"
+	default:
+		return "ED25519"
+	}
+}
+
+func VerifyPersonalMessage(message string, signature string) (signer string, pass bool, err error) {
+	b64Message := base64.StdEncoding.EncodeToString([]byte(message))
+	return VerifyMessage(b64Message, signature, constant.PersonalMessageIntentScope)
+}
+
+func VerifyTransaction(b64Message string, signature string) (signer string, pass bool, err error) {
+	return VerifyMessage(b64Message, signature, constant.TransactionDataIntentScope)
+}
+
+func VerifyMessage(message, signature string, scope constant.IntentScope) (signer string, pass bool, err error) {
+	b64Bytes, _ := base64.StdEncoding.DecodeString(message)
+	messageBytes := NewMessageWithIntent(b64Bytes, scope)
+
+	serializedSignature, err := FromSerializedSignature(signature)
+	if err != nil {
+		return "", false, err
+	}
+	digest := blake2b.Sum256(messageBytes)
+
+	pass = ed25519.Verify(serializedSignature.PubKey[:], digest[:], serializedSignature.Signature)
+
+	signer = Ed25519PublicKeyToSuiAddress(serializedSignature.PubKey)
+	if err != nil {
+		return "", false, fmt.Errorf("invalid signer %v", err)
+	}
+
+	return
+}
+
+func Ed25519PublicKeyToSuiAddress(pubKey []byte) string {
+	newPubkey := []byte{byte(SigFlagEd25519)}
+	newPubkey = append(newPubkey, pubKey...)
+
+	addrBytes := blake2b.Sum256(newPubkey)
+	return fmt.Sprintf("0x%s", hex.EncodeToString(addrBytes[:])[:64])
+}
diff --git a/signer/intent.go b/signer/intent.go
deleted file mode 100644
index 85f3bc9..0000000
--- a/signer/intent.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package signer
-
-type AppId int
-
-const (
-	Sui AppId = 0
-)
-
-type IntentVersion int
-
-const (
-	V0 IntentVersion = 0
-)
-
-type IntentScope int
-
-const (
-	TransactionData    IntentScope = 0
-	TransactionEffects IntentScope = 1
-	CheckpointSummary  IntentScope = 2
-	PersonalMessage    IntentScope = 3
-)
-
-func IntentWithScope(intentScope IntentScope) []int {
-	return []int{int(intentScope), int(V0), int(Sui)}
-}
-
diff --git a/signer/signer.go b/signer/signer.go
index 86e56a9..5067fc1 100644
--- a/signer/signer.go
+++ b/signer/signer.go
@@ -1,9 +1,14 @@
 package signer
 
 import (
+	"crypto"
 	"crypto/ed25519"
+	"encoding/base64"
 	"encoding/hex"
+
 	"github.com/block-vision/sui-go-sdk/common/keypair"
+	"github.com/block-vision/sui-go-sdk/constant"
+	"github.com/block-vision/sui-go-sdk/models"
 	"github.com/tyler-smith/go-bip39"
 	"golang.org/x/crypto/blake2b"
 )
@@ -49,3 +54,42 @@ func NewSignertWithMnemonic(mnemonic string) (*Signer, error) {
 	}
 	return NewSigner(key.Key), nil
 }
+
+type SignedMessageSerializedSig struct {
+	Message   string `json:"message"`
+	Signature string `json:"signature"`
+}
+
+func (s *Signer) SignMessage(data string, scope constant.IntentScope) (*SignedMessageSerializedSig, error) {
+	txBytes, _ := base64.StdEncoding.DecodeString(data)
+	message := models.NewMessageWithIntent(txBytes, scope)
+	digest := blake2b.Sum256(message)
+	var noHash crypto.Hash
+	sigBytes, err := s.PriKey.Sign(nil, digest[:], noHash)
+	if err != nil {
+		return nil, err
+	}
+
+	ret := &SignedMessageSerializedSig{
+		Message:   data,
+		Signature: models.ToSerializedSignature(sigBytes, s.PriKey.Public().(ed25519.PublicKey)),
+	}
+	return ret, nil
+}
+
+func (s *Signer) SignTransaction(b64TxBytes string) (*models.SignedTransactionSerializedSig, error) {
+	result, err := s.SignMessage(b64TxBytes, constant.PersonalMessageIntentScope)
+	if err != nil {
+		return nil, err
+	}
+
+	return &models.SignedTransactionSerializedSig{
+		TxBytes:   result.Message,
+		Signature: result.Signature,
+	}, nil
+}
+
+func (s *Signer) SignPersonalMessage(message string) (*SignedMessageSerializedSig, error) {
+	b64Message := base64.StdEncoding.EncodeToString([]byte(message))
+	return s.SignMessage(b64Message, constant.PersonalMessageIntentScope)
+}