Unauthenticated Encryption

[ghost]

See here: https://github.com/JaCraig/Craig-s-Utility-Library/blob/master/Utilities/IO/Encryption/BaseClasses/SymmetricBase.cs#L159

This method doesn't include any type of authentication, to be secure, a MAC should be applied. This answer goes into some detail about what you should be doing here.

If you don't authenticate the ciphertext, an attacker can make simple changes to it, and when decrypted, will change the content of the encrypted message. So it's important to ensure the integrity of the message before decrypting it.