A message may be accompanied with a digital signature, a MAC or a message hash, as a proof of some kind. Which assurances does each primitive provide to the recipient? What kind of keys are needed?
I was reading the paper $$ and came across the scheme that I show below. While I understand the scheme well, I don't understand why they prepend a 0 to the block containing $r$ and a 1 to all other ...
I found this simple proposal for a MAC algorithm: Let the MAC of message M (which consists of message blocks $M_1$,$M_2$, ..., $M_n$) be the AES encryption with key K of the XOR of all the ...