What block cipher is used for CBC-MAC? DES, AES, 3DES? Or it doesn't matter?
Is $mac = enc(hash(x))$ a secure MAC for hash = SHA256 and enc AES in CBC mode or ECB mode. Normally AES-CBC is malleable. But in this case I use a hash function for the one-way property. For ...
I'm preparing myself to exam, but I have a lot of troubles with rigorous proofs. This post is very long, but this is because I remind here 2 long definitions. At the beginning I want to remind the ...