diff --git a/signature/cose/conformance_test.go b/signature/cose/conformance_test.go
new file mode 100644
index 00000000..0bfe3216
--- /dev/null
+++ b/signature/cose/conformance_test.go
@@ -0,0 +1,215 @@
+package cose
+
+import (
+	"bytes"
+	"crypto/x509"
+	"encoding/hex"
+	"encoding/json"
+	"os"
+	"reflect"
+	"sort"
+	"testing"
+	"time"
+
+	"github.com/notaryproject/notation-core-go/signature"
+	"github.com/notaryproject/notation-core-go/testhelper"
+	"github.com/veraison/go-cose"
+)
+
+type sign1 struct {
+	SigningTime        int64       `json:"signingTime"`
+	Expiry             int64       `json:"expiry"`
+	Payload            string      `json:"payload"`
+	ProtectedHeaders   *cborStruct `json:"protectedHeaders"`
+	UnprotectedHeaders *cborStruct `json:"unprotectedHeaders"`
+	Output             cborStruct  `json:"expectedOutput"`
+}
+
+type cborStruct struct {
+	CBORHex  string `json:"cborHex"`
+	CBORDiag string `json:"cborDiag"`
+}
+
+func TestConformance(t *testing.T) {
+	data, err := os.ReadFile("testdata/conformance.json")
+	if err != nil {
+		t.Fatalf("os.ReadFile() failed. Error = %s", err)
+	}
+	var sign1 sign1
+	err = json.Unmarshal(data, &sign1)
+	if err != nil {
+		t.Fatalf("json.Unmarshal() failed. Error = %s", err)
+	}
+	testSign(t, &sign1)
+	testVerify(t, &sign1)
+}
+
+// testSign does conformance check on COSE_Sign1_Tagged
+func testSign(t *testing.T, sign1 *sign1) {
+	signRequest, err := getSignReq(sign1)
+	if err != nil {
+		t.Fatalf("getSignReq() failed. Error = %s", err)
+	}
+	env := createNewEnv(nil)
+	encoded, err := env.Sign(signRequest)
+	if err != nil || len(encoded) == 0 {
+		t.Fatalf("Sign() faild. Error = %s", err)
+	}
+	newMsg := generateSign1(env.base)
+	got, err := newMsg.MarshalCBOR()
+	if err != nil {
+		t.Fatalf("MarshalCBOR() faild. Error = %s", err)
+	}
+
+	// sign1.Output.CBORHex is a manually computed CBOR hex used as ground
+	// truth in the conformance test.
+	want := hexToBytes(sign1.Output.CBORHex)
+	if !bytes.Equal(want, got) {
+		t.Fatalf("unexpected output:\nwant: %x\n got: %x", want, got)
+	}
+
+	// Verify using the same envelope struct
+	// (Verify with UnmarshalCBOR is covered in the testVerify() part)
+	_, _, err = env.Verify()
+	if err != nil {
+		t.Fatalf("Verify() failed. Error = %s", err)
+	}
+}
+
+// testVerify does conformance check by decoding COSE_Sign1_Tagged object
+// into Sign1Message
+func testVerify(t *testing.T, sign1 *sign1) {
+	signRequest, err := getSignReq(sign1)
+	if err != nil {
+		t.Fatalf("getSignReq() failed. Error = %s", err)
+	}
+	env := createNewEnv(nil)
+	encoded, err := env.Sign(signRequest)
+	if err != nil || len(encoded) == 0 {
+		t.Fatalf("Sign() faild. Error = %s", err)
+	}
+	//Verify after UnmarshalCBOR
+	var msg cose.Sign1Message
+	// sign1.Output.CBORHex is a manually computed CBOR hex used as ground
+	// truth in the conformance test.
+	if err := msg.UnmarshalCBOR(hexToBytes(sign1.Output.CBORHex)); err != nil {
+		t.Fatalf("msg.UnmarshalCBOR() failed. Error = %s", err)
+	}
+
+	// Not doing conformance check on CertChain and signature fields,
+	// becase every time we run this test, a new certChain and signer would be
+	// generated, and hence, a new signature would be generated after Sign().
+	// Instead, CertChain is verified in verifySignerInfo(), and signature is
+	// verified by go-cose's Verify() later on.
+	certs := []*x509.Certificate{testhelper.GetRSALeafCertificate().Cert, testhelper.GetRSARootCertificate().Cert}
+	certChain := make([]interface{}, len(certs))
+	for i, c := range certs {
+		certChain[i] = c.Raw
+	}
+	msg.Headers.Unprotected[cose.HeaderLabelX5Chain] = certChain
+	msg.Signature = env.base.Signature
+
+	newEnv := createNewEnv(&msg)
+	payload, signerInfo, err := newEnv.Verify()
+	if err != nil {
+		t.Fatalf("Verify() failed. Error = %s", err)
+	}
+	verifyPayload(payload, signRequest, t)
+	verifySignerInfo(signerInfo, signRequest, t)
+}
+
+func getSignReq(sign1 *sign1) (*signature.SignRequest, error) {
+	certs := []*x509.Certificate{testhelper.GetRSALeafCertificate().Cert, testhelper.GetRSARootCertificate().Cert}
+	signer, err := signature.NewLocalSigner(certs, testhelper.GetRSALeafCertificate().PrivateKey)
+	if err != nil {
+		return &signature.SignRequest{}, err
+	}
+	signRequest := &signature.SignRequest{
+		Payload: signature.Payload{
+			ContentType: signature.MediaTypePayloadV1,
+			Content:     []byte("hello COSE"),
+		},
+		Signer:      signer,
+		SigningTime: time.Unix(sign1.SigningTime, 0).Truncate(time.Second),
+		Expiry:      time.Unix(sign1.Expiry, 0).Truncate(time.Second),
+		ExtendedSignedAttributes: []signature.Attribute{
+			{Key: "signedCritKey1", Value: "signedCritValue1", Critical: true},
+			{Key: "signedKey1", Value: "signedValue1", Critical: false},
+		},
+		SigningAgent:  "NotationConformanceTest/1.0.0",
+		SigningScheme: "notary.x509",
+	}
+	return signRequest, nil
+}
+
+func hexToBytes(s string) []byte {
+	b, err := hex.DecodeString(s)
+	if err != nil {
+		panic(err)
+	}
+	return b
+}
+
+func verifySignerInfo(signInfo *signature.SignerInfo, request *signature.SignRequest, t *testing.T) {
+	if request.SigningAgent != signInfo.UnsignedAttributes.SigningAgent {
+		t.Fatalf("SigningAgent: expected value %q but found %q", request.SigningAgent, signInfo.UnsignedAttributes.SigningAgent)
+	}
+
+	if request.SigningTime.Format(time.RFC3339) != signInfo.SignedAttributes.SigningTime.Format(time.RFC3339) {
+		t.Fatalf("SigningTime: expected value %q but found %q", request.SigningTime, signInfo.SignedAttributes.SigningTime)
+	}
+
+	if request.Expiry.Format(time.RFC3339) != signInfo.SignedAttributes.Expiry.Format(time.RFC3339) {
+		t.Fatalf("Expiry: expected value %q but found %q", request.SigningTime, signInfo.SignedAttributes.Expiry)
+	}
+
+	if !areAttrEqual(request.ExtendedSignedAttributes, signInfo.SignedAttributes.ExtendedAttributes) {
+		if !(len(request.ExtendedSignedAttributes) == 0 && len(signInfo.SignedAttributes.ExtendedAttributes) == 0) {
+			t.Fatalf("Mistmatch between expected and actual ExtendedAttributes")
+		}
+	}
+
+	signer, err := getSigner(request.Signer)
+	if err != nil {
+		t.Fatalf("getSigner() failed. Error = %s", err)
+	}
+	certs := signer.CertificateChain()
+	if err != nil || !reflect.DeepEqual(certs, signInfo.CertificateChain) {
+		t.Fatalf("Mistmatch between expected and actual CertificateChain")
+	}
+}
+
+func verifyPayload(payload *signature.Payload, request *signature.SignRequest, t *testing.T) {
+	if request.Payload.ContentType != payload.ContentType {
+		t.Fatalf("PayloadContentType: expected value %q but found %q", request.Payload.ContentType, payload.ContentType)
+	}
+
+	if !bytes.Equal(request.Payload.Content, payload.Content) {
+		t.Fatalf("Payload: expected value %q but found %q", request.Payload.Content, payload.Content)
+	}
+}
+
+func areAttrEqual(u []signature.Attribute, v []signature.Attribute) bool {
+	sort.Slice(u, func(p, q int) bool {
+		return u[p].Key < u[q].Key
+	})
+	sort.Slice(v, func(p, q int) bool {
+		return v[p].Key < v[q].Key
+	})
+	return reflect.DeepEqual(u, v)
+}
+
+func generateSign1(msg *cose.Sign1Message) *cose.Sign1Message {
+	// Not doing conformance check on CertChain and signature fields,
+	// becase every time we run this test, a new certChain and signer would be
+	// generated, and hence, a new signature would be generated after Sign().
+	// Instead, CertChain is verified in verifySignerInfo, and signature is
+	// verified by go-cose's Verify().
+	newMsg := cose.NewSign1Message()
+	newMsg.Headers.Protected = msg.Headers.Protected
+	newMsg.Headers.Unprotected["io.cncf.notary.signingAgent"] = msg.Headers.Unprotected["io.cncf.notary.signingAgent"]
+	newMsg.Payload = msg.Payload
+	// An arbitrary signature
+	newMsg.Signature = hexToBytes("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")
+	return newMsg
+}
diff --git a/signature/cose/envelope_test.go b/signature/cose/envelope_test.go
index 28fb0cc6..712abe0c 100644
--- a/signature/cose/envelope_test.go
+++ b/signature/cose/envelope_test.go
@@ -36,7 +36,7 @@ func TestParseEnvelopeError(t *testing.T) {
 }
 
 func TestSign(t *testing.T) {
-	env := envelope{}
+	env := createNewEnv(nil)
 	for _, signingScheme := range signingSchemeString {
 		for _, keyType := range signaturetest.KeyTypes {
 			for _, size := range signaturetest.GetKeySizes(keyType) {
@@ -112,7 +112,7 @@ func TestSign(t *testing.T) {
 }
 
 func TestSignErrors(t *testing.T) {
-	env := envelope{}
+	env := createNewEnv(nil)
 	// Testing getSigner()
 	t.Run("errorLocalSigner: when getSigner has privateKeyError", func(t *testing.T) {
 		signRequest, err := getSignRequest()
@@ -278,9 +278,7 @@ func TestSignErrors(t *testing.T) {
 
 func TestVerifyErrors(t *testing.T) {
 	t.Run("when missing COSE signature envelope", func(t *testing.T) {
-		env := envelope{
-			base: nil,
-		}
+		env := createNewEnv(nil)
 		_, _, err := env.Verify()
 		expected := errors.New("missing COSE signature envelope")
 		if !isErrEqual(expected, err) {
@@ -645,7 +643,7 @@ func TestSignerInfoErrors(t *testing.T) {
 }
 
 func TestSignAndVerify(t *testing.T) {
-	env := envelope{}
+	env := createNewEnv(nil)
 	for _, signingScheme := range signingSchemeString {
 		for _, keyType := range signaturetest.KeyTypes {
 			for _, size := range signaturetest.GetKeySizes(keyType) {
@@ -661,6 +659,8 @@ func TestSignAndVerify(t *testing.T) {
 					}
 
 					// Verify using the same envelope struct
+					// (Verify with UnmarshalCBOR is covered in the
+					// TestSignAndParseVerify() part)
 					_, _, err = env.Verify()
 					if err != nil {
 						t.Fatalf("Verify() failed. Error = %s", err)
@@ -721,20 +721,18 @@ func getSignRequest() (*signature.SignRequest, error) {
 func getVerifyCOSE(signingScheme string, keyType signature.KeyType, size int) (envelope, error) {
 	signRequest, err := newSignRequest(signingScheme, keyType, size)
 	if err != nil {
-		return envelope{}, err
+		return createNewEnv(nil), err
 	}
 	env := NewEnvelope()
 	encoded, err := env.Sign(signRequest)
 	if err != nil {
-		return envelope{}, err
+		return createNewEnv(nil), err
 	}
 	var msg cose.Sign1Message
 	if err := msg.UnmarshalCBOR(encoded); err != nil {
-		return envelope{}, err
-	}
-	newEnv := envelope{
-		base: &msg,
+		return createNewEnv(nil), err
 	}
+	newEnv := createNewEnv(&msg)
 	return newEnv, nil
 }
 
@@ -846,3 +844,9 @@ func isErrEqual(wanted, got error) bool {
 	}
 	return false
 }
+
+func createNewEnv(msg *cose.Sign1Message) envelope {
+	return envelope{
+		base: msg,
+	}
+}
diff --git a/signature/cose/testdata/conformance.json b/signature/cose/testdata/conformance.json
new file mode 100644
index 00000000..254e69d0
--- /dev/null
+++ b/signature/cose/testdata/conformance.json
@@ -0,0 +1,19 @@
+{
+    "title": "Sign1 - RSASSA-PSS w/ SHA-384 (sign)",
+    "description": "Sign with one signer using RSASSA-PSS w/ SHA-384",
+    "signingTime": 1661321924,
+    "expiry": 1661408324,
+    "payload": "68656C6C6F20434F5345",
+    "protectedHeaders": {
+    "cborHex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
+    "cborDiag": "{1: -38, 2: [\"io.cncf.notary.signingScheme\", \"io.cncf.notary.expiry\", \"signedCritKey1\"], 3: \"application/vnd.cncf.notary.payload.v1+json\", \"signedKey1\": \"signedValue1\", \"signedCritKey1\": \"signedCritValue1\", \"io.cncf.notary.expiry\": 1661408324, \"io.cncf.notary.signingTime\": 1661321924, \"io.cncf.notary.signingScheme\": \"notary.x509\"}"
+    },
+    "unprotectedHeaders": {
+    "cborHex": "A1781B696F2E636E63662E6E6F746172792E7369676E696E674167656E74781D4E6F746174696F6E436F6E666F726D616E6365546573742F312E302E30",
+    "cborDiag": "{\"io.cncf.notary.signingAgent\":\"NotationConformanceTest/1.0.0\"}"
+    },
+    "expectedOutput": {
+    "cborHex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
+    "cborDiag": "18([h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{\"io.cncf.notary.signingAgent\":\"NotationConformanceTest/1.0.0\"}, h'68656C6C6F20434F5345', h'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'])"
+    }
+}