byte[] encrypted2 = storage.encryptCredentials(plaintext.clone());

        // Should produce different ciphertexts due to random IV
        assertFalse(Arrays.equals(encrypted1, encrypted2), "Different encryptions should produce different ciphertexts");

        // But both should decrypt to same plaintext
        char[] decrypted1 = storage.decryptCredentials(encrypted1);

                // Process AAD (not included in ciphertext)
                cipher.processAADBytes(associatedData, 0, associatedData.length);

                // Process ciphertext + auth tag
                final byte[] input = new byte[ciphertext.length + authTag.length];
                System.arraycopy(ciphertext, 0, input, 0, ciphertext.length);

     * @param clearText the 8-byte plaintext block
     * @param cipherText the output 8-byte ciphertext block
     */
    public void encrypt(final byte[] clearText, final byte[] cipherText) {
        encrypt(clearText, 0, cipherText, 0);
    }

    /// Decrypt a block of bytes.
    /**
     * Decrypts an 8-byte block using DES
     * @param cipherText the 8-byte ciphertext block
     * @param clearText the output 8-byte plaintext block

            // Encrypt
            byte[] ciphertext = cipher.doFinal(plaintextBytes);

            // Combine IV and ciphertext
            byte[] result = new byte[GCM_IV_SIZE + ciphertext.length];
            System.arraycopy(iv, 0, result, 0, GCM_IV_SIZE);
            System.arraycopy(ciphertext, 0, result, GCM_IV_SIZE, ciphertext.length);

            return result;

        } finally {