← Back to context

Comment by thomasahle

6 hours ago

It's true that you can use AES instructions now on some computers, bit I honestly don't see why you'd use a heuristic hash (even if cryptographic) when you can get provable guarantees with k-wise independent hashing. Our paper makes these even faster than they already were.

See section 5.7 and 5.8 in the paper for experiments against other hashes.

You benchmarked a really old heuristic hash in Murmur and xxh64. xxh3 is ~1.6x to 1.8x faster than xxh64 - extrapolating that to 5.7 in your paper puts it at ~18-27% faster. WyHash and UMash sometimes report faster numbers.

Even xxh3 isn't the cutting edge - gxhash (~1.8x faster) and aesni (~1.5x faster) use AES instructions. Compared to your approach that perf disparity should grow to ~30-40%.

Hopefully that answers your question about why someone might still choose to use heuristic hashing rather than k-wise independent hashing when collision resistance isn't critical.