}
        if (masterPassword != null) {
            Arrays.fill(masterPassword, '\0');
        }
    }

    @Test
    public void testEncryptDecrypt() throws Exception {
        char[] plaintext = "SecretPassword123".toCharArray();

        // Encrypt
        byte[] encrypted = storage.encryptCredentials(plaintext);
        assertNotNull(encrypted, "Encrypted data should not be null");