SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(KEY_DERIVATION_ALGORITHM);
        KeySpec keySpec = new PBEKeySpec(password, salt, PBKDF2_ITERATIONS, KEY_SIZE);
        SecretKey tempKey = keyFactory.generateSecret(keySpec);
        return new SecretKeySpec(tempKey.getEncoded(), KEY_ALGORITHM);
    }

    /**
     * Convert char array to byte array (UTF-8)
     */
    private byte[] charsToBytes(char[] chars) {