• antirez's avatar
    SipHash 2-4 -> SipHash 1-2. · 0285c271
    antirez authored
    For performance reasons we use a reduced rounds variant of
    SipHash. This should still provide enough protection and the
    effects in the hash table distribution are non existing.
    If some real world attack on SipHash 1-2 will be found we can
    trivially switch to something more secure. Anyway it is a
    big step forward from Murmurhash, for which it is trivial to
    generate *seed independent* colliding keys... The speed
    penatly introduced by SipHash 2-4, around 4%, was a too big
    price to pay compared to the effectiveness of the HashDoS
    attack against SipHash 1-2, and considering so far in the
    Redis history, no such an incident ever happened even while
    using trivially to collide hash functions.
    0285c271
siphash.c 13.5 KB