4 ms·

Oh, well. What I think of as "cryptographic hash function" is a function resistent to pre-image attack, second pre-image attack, and collision generation. Nei

by ticki_ 10y ago

Oh, well. What I think of as "cryptographic hash function" is a function resistent to pre-image attack, second pre-image attack, and collision generation. Neither of those are satisfied by SipHash, and can thus not classify as a cryptographic hash function by the normal definition.

tptacek 10y ago
It's a cryptographic hash function, but not one suitable for all of the same applications as SHA2. It has security characteristics that other hash-table hashes (for instance) lack.
- ticki_ 10y ago
  If you know the key, it is as weak as it gets (as the paper notes too, you can construct collisions easily if the key is known), so I disagree.
  - tptacek 10y ago
    Honestly, I really don't care about this debate, except to the extent that it's about whether SipHash "isn't cryptographic and therefore you might as well use CityHash or SeaHash", which just isn't true.
    - ticki_ 10y ago
      I agree. SipHash is certainly strong if you don't know the key.