public void Encrypt(string plainText)
        {
            var plainBytes     = _bytesUtil.FromString(plainText);
            var encryptedBytes = _aesCryptoUtil.Encrypt(plainBytes);
            var encryptedText  = _bytesUtil.ToBase64(encryptedBytes);

            Console.WriteLine("Plain text:{0}, encrypted text:{1}", plainText, encryptedText);
        }
        public void Sign(string text)
        {
            var bytes          = _bytesUtil.FromString(text);
            var signatureBytes = _rsaCryptoUtil.Sign(bytes, _key.Private);
            var signature      = _bytesUtil.ToBase64(signatureBytes);

            Console.WriteLine("Text:{0}, signature:{1}", text, signature);
        }