4 ms·

Better performance. For a hash table, a cryptographic hash function is overkill (i.e. spends a lot of time to provide security properties that are not needed).

• bsder 2y ago
  > For a hash table, a cryptographic hash function is overkill (i.e. spends a lot of time to provide security properties that are not needed). Except, as we quickly find out, attackers can often exploit a non-cryptographic hash to create a denial of service attack. The problem is that if my hash function is really a performance bottleneck, I'm probably better off using a really shitty hash function that exploits some feature of the data being stored that is "good enough" but super fast. In that case, even a non-crypto hash function won't be fast enough. Finally, hash tables result in "random-ish" memory access patterns. On a modern processor, random memory access is so horrifically slow that you may get superior performance by changing data structures to something with a much more linear access pattern and dumping the idea of hash tables altogether.
  • twiss 2y ago
    There is a middle ground possible as mentioned in the paper, e.g. SipHash is a non-cryptographic hash function that provides security against DoS against attacks.