wyhash
smhasher
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wyhash | smhasher | |
---|---|---|
9 | 30 | |
909 | 1,690 | |
- | - | |
6.6 | 7.1 | |
3 months ago | about 2 months ago | |
C | C++ | |
The Unlicense | 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.
wyhash
- Wyhash: The fastest quality hash function
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What hash function you use for hash maps / hash tables?
I recently switched to wyhash as it seems to have a good combination of speed and stability.
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Are there any weaker hashes than MD5, but still randomly distributed?
wyhash is a decent option for if you don't need a cryptographical quality hash
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Hacker News top posts: Mar 15, 2021
New Bare Hash Map: 2X-3X Speedup over SOTA\ (32 comments)
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New Bare Hash Map: 2X-3X Speedup over SOTA
I feel like you’d want something a bit safer than “we don’t store the keys and just rely on the hash to be really good” [1], putting “please do not use this for serious tasks” in a comment embedded in the header file isn’t a clear enough warning.
It’s not clear to me that that probability of collision assumptions hold. It’s basically assuming that the hashing is perfect and distributes any inputs to the full 64-bit space with uniform probability. That’s the usual hash map / randomized algorithm hope, but does BigCrush or similar avalanche testing really prove that? (Presumably not, otherwise there wouldn’t be image attacks for things like md5).
[1] https://github.com/wangyi-fudan/wyhash/blob/d2a305811972f391...
- wyhash and wyrand are a non-cryptographic 64-bit hash function and PRNG respectively
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.
What are some alternatives?
aHash - aHash is a non-cryptographic hashing algorithm that uses the AES hardware instruction
xxHash - Extremely fast non-cryptographic hash algorithm
meow_hash - Official version of the Meow hash, an extremely fast level 1 hash
BLAKE3 - the official Rust and C implementations of the BLAKE3 cryptographic hash function
leocad - A CAD application for creating virtual LEGO models
Hashids.java - Hashids algorithm v1.0.0 implementation in Java
smhasher - Automatically exported from code.google.com/p/smhasher
png-decoder - A pure-Rust, no_std compatible PNG decoder
Mersenne-Twister-in-Python - A Mersenne Twister Random Number Generator
rustls - A modern TLS library in Rust
countwords - Playing with counting word frequencies (and performance) in various languages.
Halide - a language for fast, portable data-parallel computation