diff --git a/pkg/signature.go b/pkg/signature.go
index 7322c50..992b183 100644
--- a/pkg/signature.go
+++ b/pkg/signature.go
@@ -42,3 +42,35 @@ func (s *Signature) SetSign(v []byte) {
 func (s *Signature) ToV2() *refs.Signature {
 	return (*refs.Signature)(s)
 }
+
+// Marshal marshals Signature into a protobuf binary form.
+//
+// Buffer is allocated when the argument is empty.
+// Otherwise, the first buffer is used.
+func (s *Signature) Marshal(b ...[]byte) ([]byte, error) {
+	var buf []byte
+	if len(b) > 0 {
+		buf = b[0]
+	}
+
+	return (*refs.Signature)(s).
+		StableMarshal(buf)
+}
+
+// Unmarshal unmarshals protobuf binary representation of Signature.
+func (s *Signature) Unmarshal(data []byte) error {
+	return (*refs.Signature)(s).
+		Unmarshal(data)
+}
+
+// MarshalJSON encodes Signature to protobuf JSON format.
+func (s *Signature) MarshalJSON() ([]byte, error) {
+	return (*refs.Signature)(s).
+		MarshalJSON()
+}
+
+// UnmarshalJSON decodes Signature from protobuf JSON format.
+func (s *Signature) UnmarshalJSON(data []byte) error {
+	return (*refs.Signature)(s).
+		UnmarshalJSON(data)
+}
diff --git a/pkg/signature_test.go b/pkg/signature_test.go
new file mode 100644
index 0000000..72196c8
--- /dev/null
+++ b/pkg/signature_test.go
@@ -0,0 +1,33 @@
+package pkg
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSignatureEncoding(t *testing.T) {
+	s := NewSignature()
+	s.SetKey([]byte("key"))
+	s.SetSign([]byte("sign"))
+
+	t.Run("binary", func(t *testing.T) {
+		data, err := s.Marshal()
+		require.NoError(t, err)
+
+		s2 := NewSignature()
+		require.NoError(t, s2.Unmarshal(data))
+
+		require.Equal(t, s, s2)
+	})
+
+	t.Run("json", func(t *testing.T) {
+		data, err := s.MarshalJSON()
+		require.NoError(t, err)
+
+		s2 := NewSignature()
+		require.NoError(t, s2.UnmarshalJSON(data))
+
+		require.Equal(t, s, s2)
+	})
+}
diff --git a/v2/refs/json.go b/v2/refs/json.go
index 3fe253e..dd0f836 100644
--- a/v2/refs/json.go
+++ b/v2/refs/json.go
@@ -104,3 +104,23 @@ func (v *Version) UnmarshalJSON(data []byte) error {
 
 	return nil
 }
+
+func (s *Signature) MarshalJSON() ([]byte, error) {
+	return protojson.MarshalOptions{
+		EmitUnpopulated: true,
+	}.Marshal(
+		SignatureToGRPCMessage(s),
+	)
+}
+
+func (s *Signature) UnmarshalJSON(data []byte) error {
+	msg := new(refs.Signature)
+
+	if err := protojson.Unmarshal(data, msg); err != nil {
+		return err
+	}
+
+	*s = *SignatureFromGRPCMessage(msg)
+
+	return nil
+}
diff --git a/v2/refs/json_test.go b/v2/refs/json_test.go
index ae41e9f..5671ed2 100644
--- a/v2/refs/json_test.go
+++ b/v2/refs/json_test.go
@@ -69,3 +69,15 @@ func TestVersionSON(t *testing.T) {
 
 	require.Equal(t, v, v2)
 }
+
+func TestSignatureSON(t *testing.T) {
+	s := generateSignature("key", "sig")
+
+	data, err := s.MarshalJSON()
+	require.NoError(t, err)
+
+	s2 := new(refs.Signature)
+	require.NoError(t, s2.UnmarshalJSON(data))
+
+	require.Equal(t, s, s2)
+}
diff --git a/v2/refs/marshal.go b/v2/refs/marshal.go
index 353729c..5f2358b 100644
--- a/v2/refs/marshal.go
+++ b/v2/refs/marshal.go
@@ -266,6 +266,17 @@ func (s *Signature) StableSize() (size int) {
 	return size
 }
 
+func (s *Signature) Unmarshal(data []byte) error {
+	m := new(refs.Signature)
+	if err := goproto.Unmarshal(data, m); err != nil {
+		return err
+	}
+
+	*s = *SignatureFromGRPCMessage(m)
+
+	return nil
+}
+
 func (v *Version) StableMarshal(buf []byte) ([]byte, error) {
 	if v == nil {
 		return []byte{}, nil
diff --git a/v2/refs/marshal_test.go b/v2/refs/marshal_test.go
index f92e361..3cead07 100644
--- a/v2/refs/marshal_test.go
+++ b/v2/refs/marshal_test.go
@@ -95,16 +95,14 @@ func TestChecksum_StableMarshal(t *testing.T) {
 
 func TestSignature_StableMarshal(t *testing.T) {
 	signatureFrom := generateSignature("Public Key", "Signature")
-	transport := new(grpc.Signature)
 
 	t.Run("non empty", func(t *testing.T) {
 		wire, err := signatureFrom.StableMarshal(nil)
 		require.NoError(t, err)
 
-		err = goproto.Unmarshal(wire, transport)
-		require.NoError(t, err)
+		signatureTo := new(refs.Signature)
+		require.NoError(t, signatureTo.Unmarshal(wire))
 
-		signatureTo := refs.SignatureFromGRPCMessage(transport)
 		require.Equal(t, signatureFrom, signatureTo)
 	})
 }