public static byte[] encryptHMAC(byte[] data, String key)
			throws IOException, NoSuchAlgorithmException, InvalidKeyException {
		SecretKey secretKey = new SecretKeySpec(base64Decoder(key), KEY_MAC);
		Mac mac = Mac.getInstance(secretKey.getAlgorithm());
		mac.init(secretKey);

		return mac.doFinal(data);
	}