2
votes
1answer
94 views

Why do we encrypt-then mac but sign-then-encrypt?

This question was asked in comments on my answer to should we sign then encrypt or encrypt then sign. I think posing the question as a separate entity is best, so: The general advice for applying ...
2
votes
1answer
310 views

How is digital signature different from a message authentication code (MAC)?

I know the definitions of both but can't specifically tell how they are different and if one is better than the other. Please help.
1
vote
2answers
172 views

What security flaw exists in MAC authentication scenario?

What security flaw exists (if any) in the solution of this non-encrypted authentication scenario? An unencrypted message passes one-way from computer A to B. Its transmission is viewable by the ...
13
votes
1answer
6k views

What are the differences between a digital signature, a MAC and a hash?

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?
5
votes
1answer
508 views

Why are MACs in general deterministic, whereas digital signature constructions are randomized?

The fact is I'm not quite sure if my question statement is true, however all the MAC constructions I know of (e.g. CBC-MAC, CMAC, HMAC) are deterministic, whereas many constructions for digital ...