diff --git a/ecsvdp_dh_key_agreement.go b/ecsvdp_dh_key_agreement.go
index 84e3031..687210b 100644
--- a/ecsvdp_dh_key_agreement.go
+++ b/ecsvdp_dh_key_agreement.go
@@ -20,12 +20,12 @@ func NewEcsvdpDhKeyAgreement() *EcsvdpDhKeyAgreement {
 	return &EcsvdpDhKeyAgreement{}
 }
 
-//CalculateAgreement calculate a key following 1363 7.2.1 ECSVDP-DH
+// CalculateAgreement calculate a key following 1363 7.2.1 ECSVDP-DH
 func (ka *EcsvdpDhKeyAgreement) CalculateAgreement(privateKey *PrivateKey, anotherPublicKey *PublicKey) ([]byte, error) {
-	if anotherPublicKey == nil {
+	if anotherPublicKey == nil || anotherPublicKey.X == nil || anotherPublicKey.Y == nil {
 		return nil, invalidEphemeralPublicKey
 	}
-	if privateKey == nil {
+	if privateKey == nil || privateKey.D == nil || privateKey.Curve == nil {
 		return nil, invalidPrivateKey
 	}
 
diff --git a/ecsvdp_dh_key_agreement_test.go b/ecsvdp_dh_key_agreement_test.go
index a492f07..b87d206 100644
--- a/ecsvdp_dh_key_agreement_test.go
+++ b/ecsvdp_dh_key_agreement_test.go
@@ -32,4 +32,48 @@ func TestCalculateAgreement(t *testing.T) {
 	assert.NotNil(t, realZ)
 
 	assert.Equal(t, string(expectedZ), string(realZ))
+
+}
+
+func TestCalculateAgreementWithInvalidParams(t *testing.T) {
+	{
+		realZ, err := NewEcsvdpDhKeyAgreement().CalculateAgreement(nil, nil)
+		assert.Nil(t, realZ)
+		assert.Equal(t, invalidEphemeralPublicKey, err)
+	}
+	{
+		privateKey := &PrivateKey{}
+		anotherPublicKey := &PublicKey{}
+		realZ, err := NewEcsvdpDhKeyAgreement().CalculateAgreement(privateKey, anotherPublicKey)
+		assert.Nil(t, realZ)
+		assert.NotNil(t, err)
+		assert.Equal(t, invalidEphemeralPublicKey, err)
+	}
+	{
+		privateKey := &PrivateKey{}
+		publicBytes, err := hex.DecodeString("040fe85dfc76083c4d3e9dda070df0ce6bc5b7a837c2b7975c32df26cca3f610725fa4d126cc2d0cc23762dbb199e5f7f4bc6281946f0086ef0800d288192aa1da")
+		anotherPublicKey, err := DeserializePublicKey(publicBytes)
+		assert.Nil(t, err)
+		assert.NotNil(t, anotherPublicKey)
+		realZ, err := NewEcsvdpDhKeyAgreement().CalculateAgreement(privateKey, anotherPublicKey)
+		assert.Nil(t, realZ)
+		assert.Equal(t, invalidPrivateKey, err)
+	}
+	{
+		privateBytes, err := hex.DecodeString("7819b30ff63ebd35f9fcf4233ccb7ecd8e9d90db8ec977cdf7b1f7bdc212b238")
+		assert.Nil(t, err)
+
+		privateKey := DeserializePrivateKey(privateBytes)
+		assert.NotNil(t, privateKey)
+		privateKey.Curve = nil
+
+		publicBytes, err := hex.DecodeString("040fe85dfc76083c4d3e9dda070df0ce6bc5b7a837c2b7975c32df26cca3f610725fa4d126cc2d0cc23762dbb199e5f7f4bc6281946f0086ef0800d288192aa1da")
+		anotherPublicKey, err := DeserializePublicKey(publicBytes)
+		assert.Nil(t, err)
+		assert.NotNil(t, anotherPublicKey)
+
+		realZ, err := NewEcsvdpDhKeyAgreement().CalculateAgreement(privateKey, anotherPublicKey)
+		assert.Nil(t, realZ)
+		assert.Equal(t, invalidPrivateKey, err)
+	}
 }
diff --git a/test.sh b/test.sh
new file mode 100644
index 0000000..cd2906a
--- /dev/null
+++ b/test.sh
@@ -0,0 +1,2 @@
+go clean --cache
+go test ./...
\ No newline at end of file