fix Encrypt

dppk.go

@@ -171,16 +171,16 @@ RETRY:
 }
 
 // Encrypt encrypts a message using the given public key.
-func (priv *PrivateKey) Encrypt(pk *PublicKey, msg []byte) (Ps *big.Int, Qs *big.Int, err error) {
+func Encrypt(pk *PublicKey, msg []byte) (Ps *big.Int, Qs *big.Int, err error) {
 	// Convert the message to a big integer
 	secret := new(big.Int).SetBytes(msg)
-	if secret.Cmp(priv.PublicKey.prime) >= 0 {
+	if secret.Cmp(pk.prime) >= 0 {
 		return nil, nil, errors.New(ERRMSG_DATA_EXCEEDED_FIELD)
 	}
 
 	// Extend the vectors U and Q with a constant term of 1
-	vecUExt := make([]*big.Int, len(priv.PublicKey.vecU)+1)
-	vecVExt := make([]*big.Int, len(priv.PublicKey.vecV)+1)
+	vecUExt := make([]*big.Int, len(pk.vecU)+1)
+	vecVExt := make([]*big.Int, len(pk.vecV)+1)
 	copy(vecUExt, pk.vecU)
 	copy(vecVExt, pk.vecV)
 	vecUExt[len(vecUExt)-1] = big.NewInt(1)

dppk_test.go

@@ -10,11 +10,9 @@ import (
 func TestDPPK(t *testing.T) {
 	alice, err := GenerateKey(10)
 	assert.Nil(t, err)
-	bob, err := GenerateKey(10)
-	assert.Nil(t, err)
 
 	secret := []byte("hello quantum")
-	Ps, Qs, err := bob.Encrypt(&alice.PublicKey, secret)
+	Ps, Qs, err := Encrypt(&alice.PublicKey, secret)
 	assert.Nil(t, err)
 	t.Log("secret:", string(secret))
 
@@ -31,11 +29,9 @@ func TestDPPKSmallPrime(t *testing.T) {
 	prime := "977"
 	alice, err := GenerateKeyWithPrime(10, prime)
 	assert.Nil(t, err)
-	bob, err := GenerateKeyWithPrime(10, prime)
-	assert.Nil(t, err)
 
 	secret := []byte("X")
-	Ps, Qs, err := bob.Encrypt(&alice.PublicKey, secret)
+	Ps, Qs, err := Encrypt(&alice.PublicKey, secret)
 	assert.Nil(t, err)
 	t.Log("secret:", string(secret))
 
@@ -75,14 +71,14 @@ func BenchmarkDPPKEncrypt(b *testing.B) {
 	dppk, _ := GenerateKey(5)
 	secret := []byte("hello quantum")
 	for i := 0; i < b.N; i++ {
-		_, _, _ = dppk.Encrypt(&dppk.PublicKey, secret)
+		_, _, _ = Encrypt(&dppk.PublicKey, secret)
 	}
 }
 
 func BenchmarkDPPKDecrypt(b *testing.B) {
 	dppk, _ := GenerateKey(5)
 	secret := []byte("hello quantum")
-	Ps, Qs, _ := dppk.Encrypt(&dppk.PublicKey, secret)
+	Ps, Qs, _ := Encrypt(&dppk.PublicKey, secret)
 	for i := 0; i < b.N; i++ {
 		_, _, _ = dppk.Decrypt(Ps, Qs)
 	}