private static void startSession() {
		Session session = Session.getInstance(true);

		Pair<BigInteger, BigInteger> privateKeys = session.getPrivateKey();

		System.out.println("");
		System.out.println("Private key x: " + privateKeys.getFirst());
		System.out.println("Private key y: " + privateKeys.getSecond());
		System.out.println("");

		System.out.println("Please introduce message to sign:");
		String text = null;
		while (text == null) {
			try {
				text = (new BufferedReader(new InputStreamReader(System.in)))
						.readLine();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		Pair<BigInteger, BigInteger> signature = DSA.sign(true, text,
				session.getGlobalKeyG(), session.getGlobalKeyP(),
				session.getGlobalKeyQ(), privateKeys.getFirst());
		System.out.println("Signature (r,s): (" + signature.getFirst() + ", "
				+ signature.getSecond() + ")");
		System.out.println("");
		System.out.println("Do you want to verify a message?");
		System.out.println("  1.Yes (y)");
		System.out.println("  2.No (press enter)");
		String alg = null;
		try {
			alg = (new BufferedReader(new InputStreamReader(System.in)))
					.readLine();
		} catch (IOException e) {
			e.printStackTrace();
		}

		switch (alg) {
		case "y":
			verifyMessage();
			break;
		default:
			System.out.println("Bye!");
			System.exit(1);
			break;

		}

	}