On 20 October 2010 17:44, Justin Lebar <justin.le...@gmail.com> wrote: > My cryptographically-inclined friend suggested we use a universal hash > function or something a bit stronger, such as VHASH. > > These functions take a "key", which we could choose at random and fix > in the code. > > VHASH outputs 64-bit digests with collision probability 2^61, so in > expectation you'd need to hash 2^30 files before you saw a collision. > If that wasn't good enough, we could compute two VHASH digests with > different keys and concatenate them.
Is VHASH expected to be faster than MD4? I don't think adding more strength will help with anything. The odds of an accidental MD4 collision are low, and I don't know of any attack by which being able to predict or produce ccache collisions accomplishes anything for the attacker. (If they can write to the cache you have bigger problems.) -- Martin _______________________________________________ ccache mailing list firstname.lastname@example.org https://lists.samba.org/mailman/listinfo/ccache