public HashUtil(String algorithm) {

		try {
			md = MessageDigest.getInstance(algorithm);
		} catch (NoSuchAlgorithmException e) {
			// TODO Auto-generated catch block
			System.err.println("[HashUtil] Severe: The algorithm "+algorithm+" is not available. Make sure that your JRE provides an implementation of " + algorithm);
			e.printStackTrace();
			System.exit(1);
		}
	}