cityhash
smhasher
cityhash | smhasher | |
---|---|---|
2 | 30 | |
1,054 | 1,703 | |
1.2% | - | |
0.0 | 6.7 | |
almost 2 years ago | 4 days ago | |
Shell | C++ | |
MIT License | GNU General Public License v3.0 or later |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
cityhash
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What hash function you use for hash maps / hash tables?
However, it's not the fastest. I found that Google CityHash was faster and produced slightly different hashvals. This was tested on billions of entries. https://github.com/google/cityhash
- Use Fast Data Algorithms
smhasher
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GxHash - A new (extremely) fast and robust hashing algorithm 🚀
The algorithm passes all SMHasher quality tests and uses rounds of AES block cipher internally, so it is quite robust! For comparison XxH3, t1ha0 and many others don't pass SMHasher (while being slower).
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The PolymurHash universal hash function
Confirmed, I tested it. https://github.com/rurban/smhasher
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Show HN: Discohash – simply, quality, fast hash
There's lots of great hash functions out there: some are super fast, like xxhash and highly optimized, others are also super fast umash and based on interesting math ideas from finite fields^1, while maintaining high quality (according to SMHasher). Others are also fast and interesting (tabulation hash, that may sometimes be seemingly universal), one of the main originators of those ideas are Mikkel Thorup^2. Anyway, a couple of years ago I also tried my hand at building hashes and created a few that passed SMHasher (tifuhash ~ a floating point hash, beamsplitter - a seemingly-universal tabulation style hash, and this one discohash - a "more traditional" ARX-based design (addition rotation xor)^3 ).
0: https://github.com/rurban/smhasher/blob/master/xxh3.h
1: https://pvk.ca/Blog/2022/12/29/fixing-hashing-modulo-alpha-e...
2: https://arxiv.org/abs/1505.01523
3: https://eprint.iacr.org/2018/898.pdf https://crypto.polito.it/content/download/480/2850/file/docu...
4: https://en.wikipedia.org/wiki/BLAKE_(hash_function)
Discohash (posted here) is the fastest one I made, it's simple and doesn't rely on any arch-specific optimizations or vector instructions (AVX etc ~ tho I suppose...they could be added? I'm definitely no expert in them, I barely get away with doing the C/C++ implementations!)
The main mixing round function is:
mix(const int A) {
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A Vulnerability in Implementations of SHA-3, Shake, EdDSA
ubsan, asan, valgrind tests are missing. some do offer symbolic verification of the algo, but not the implementations.
See my https://github.com/rurban/smhasher#crypto paragraph, and
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Academic Urban Legends
The spinach story reminds me a lot on the false recommendation of siphash for hash table DDOS prevention. https://github.com/rurban/smhasher#security
The authors came up in their widely cited paper with a proper solution to spread the random hash seed into the inner loop, vastly enhancing its security by avoiding trivial hash collision attacks. But a secure, slow hash function can never prevent from normal hash seed attacks, when the random seed is known somehow. esp. with dynamic languages it's trivial to get the seed externally.
Other trivial countermeasures must be used then, which also don't make hash tables 10x slower, keeping them practical.
- SHA-1 is out. NIST recommends switching to the SHA-2 and SHA-3 groups of hash algorithms as soon as possible, with an official deadline of Dec. 31, 2030.
- Adventures in Advent of Code
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New ScyllaDB Go Driver: Faster Than GoCQL and Its Rust Counterpart
This is the best, most comprehensive hash test suite I know of: https://github.com/rurban/smhasher/
you might want to particularly look into murmur, spooky, and metrohash. I'm not exactly sure of what the tradeoffs involved are, or what your need is, but that site should serve as a good starting point at least.
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What do you typically use for non-cryptographic hash functions?
Here is a good comparison table, as you can see, BLAKE can perform in secure way much faster than crc32, so my original point, - to use non weak hashes unless you really have a reason/requirement not to do so
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What hash function you use for hash maps / hash tables?
smhasher is a great place to testing results for a massive number of hash algorithms.