ChibiHash

A small, fast, and portable 64-bit hash function.

This is a community-maintained website to gather ChibiHash-related resources in one place. It is not affiliated with or maintained by the original ChibiHash author.

For the official repository, please visit github.com/N-R-K/ChibiHash.

Key Features

Small: ~65 loc in C
Fast: see benchmarks.
Portable: Doesn't use hardware specific instructions (e.g SSE)
Good Quality: Passes smhasher and smhasher3
Unencumbered: Released into the public domain
Free of undefined behavior and gives same result regardless of host system's endianness.
Non-cryptographic

Version Comparison

Released on 2024-11-30
Improved short string performance (34 cycles/hash)
Enhanced seeding (affects full 256-bit state)
Better mixing in bulk handling
Passes all 252 tests in smhasher3
Reworked tail-end handling inspired by wyhash

Released on 2024-11-16
Original implementation
42 cycles/hash for short strings
Basic seed mixing (affects only 64 bits of initial state)
Passes most smhasher tests

When Not to Use

Cryptographic purposes
Protection against collision attacks (Use SipHash instead)
When extremely low collision probability is required (Consider xxhash64)