murmurhash

I'm trying to use an Avalanche mixer to hash integer coordinates. I've been using Murmur3's 32bit and 64bit avalanche mixers to do so (and not the actual total hash function). For my application the entire hash function is not needed, only the Avalanche Mixer seen here: uint32_t murmurmix32( uint32_t h ) { h ^= h >> 16; h *= 0x85ebca6b; h ^= h >> 13; h *= 0xc2b2ae35; h ^= h >> 16; return h; } uint64_t murmurmix64( uint64_t h ) { h ^= h >> 33; h *= 0xff51afd7ed558ccdULL; h ^= h >> 33; h *= 0xc4ceb9fe1a85ec53ULL; h ^= h >> 33; return h; } These appear fast on my machine, I take two uint32_ts and

I'm using SHA-1 to detect duplicates in a program handling files. It is not required to be cryptographic strong and may be reversible. I found this list of fast hash functions https://code.google.com/p/xxhash/ What do I choose if I want a faster function and collision on random data near to SHA-1? Maybe a 128 bit hash is good enough for file deduplication? (vs 160 bit sha-1) In my program the hash is calculated on chuncks from 0 - 512 KB. A. Binzxxxxxx Maybe this will help you: https://softwareengineering.stackexchange.com/questions/49550/which-hashing-algorithm-is-best-for-uniqueness-and

We're trying to settle an internal debate on our dev team: We're looking for a 64-bit PHP hash function. We found a PHP implementation of MurmurHash3 , but MurmurHash3 is either 32-bit or 128-bit, not 64-bit. Co-worker #1 believes that to produce a 64-bit hash from MurmurHash3, we can simply slice the first (or last, or any) 64 bits of the 128-bit hash and that it will be as collision-proof as a native 64-bit hash function. Co-worker #2 believes that we must find a native 64-bit hash function to reduce collisions and that 64-bit slices of a 128-bit hash will not be as collision proof as a

I've been trying to get a high level understanding of what MurmurHash does. I've read a basic description but have yet to find a good explanation of when to use it and why. I know its very fast but want to know a bit more. I asked a related question about how I could fit a UUID into a Redis bitset, and someone suggested using MurmurHash. It works but I'd like to understand the risks/benefits. Murmur is a family of good general purpose hashing functions, suitable for non-cryptographic usage. As stated by Austin Appleby, MurmurHash provides the following benefits: simple (in term of number of