public void RsaEncode(System.Numerics.BigInteger key, System.Numerics.BigInteger modulus)
        {
            var length = offset;

            offset = 0;
            var data = new byte[length];

            GetBytes(data, 0, length);
            var biginteger2 = new System.Numerics.BigInteger(data);

            System.Numerics.BigInteger biginteger3 = biginteger2.modPow(key, modulus);
            byte[] @out = biginteger3.toByteArray();
            offset = 0;
            WriteBytes(@out, 0, @out.Length);
        }