This happens when I used Rijndael 128 or TripleDES 192.... The following
code always throws "Length of the data to encrypt is invalid".

ICryptoTransform trans = algorithm.CreateEncryptor(algorithm.Key,
algorithm.IV);
MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms, trans, CryptoStreamMode.Write);
cs.Write(inputBytes, 0, inputBytes.Length);
cs.FlushFinalBlock();

algorithm is a RijManaged or TDES object, inputBytes is a six-byte array in
this case.  Shouldn't this work?

How did you setup the 'algorithm' object? In particular, what padding mode
are you using?
Your code works perfectly, unless I set the PaddingMode to 'None', in which
case it is normal that the symmetric algorithm throws an exception.

Regards,
Pieter Philippaerts

How inputBytes are encoding?
You must encoding the string to encrypt. To do this you can use the
following code (for example):

byte[] inputBytes = Encoding.UTF8.GetBytes(inputString);


HTH
ciauz

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