2
$\begingroup$

I remember I read that a MAC can be considered as a PRF.

Can a variable-length input keyed-PRF be considered as a MAC?

Improve this question
$\endgroup$
1
  • 6
    $\begingroup$ I'd note that the first statement is incorrect: a secure MAC is not necessarily a secure PRF. Consider any secure MAC and add a single zero bit in the end. The result is clearly not random, but equally secure as a MAC. $\endgroup$
    – Dmitry Khovratovich
    Jul 3, 2014 at 12:49

1 Answer 1

Reset to default
3
$\begingroup$

Usually. $\:$ A variable-length input keyed-PRF is a [PRF's output length]-bit MAC.
In particular, a variable-length input keyed-PRF with long output is automatically a MAC.

Improve this answer
$\endgroup$
1
  • 2
    $\begingroup$ I would add that we are talking about secure PRFs and secure MACs. $\endgroup$
    – Dmitry Khovratovich
    Jul 3, 2014 at 12:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.