public static BigInteger preMasterSecret(BigInteger c, BigInteger s)
	{
		BigInteger pms = c.subtract(s);
		pms = pms.multiply(c);
		pms = pms.modPow(c, s);
		byte[] b = pms.toString().getBytes();
		byte[] b2 = Arrays.copyOf(b, 48);
		String r = new String(b2);
		return new BigInteger(r);
	}