Show HN: Go version of HighwayHash with optimized assembly implementations (opens in new tab)

(github.com)

48 pointsy4m4b48y ago13 comments

13 comments

loeg8y ago

How does performance compare with XXhash, possibly the current leader in the non-cryptographic hash category?

XXhash is only fast with digest workloads, not hash tables. There the hash function needs to be fast and small, XXhash is too big and trashes the icache.

The current leaders are on my smhasher site, https://github.com/rurban/smhasher/

loeg8y ago

Thank you!

zuzun8y ago

The benchmarks on the xxHash Github page were done on a 32-bit system using an old Visual C++ compiler. Of course you can beat hash functions that were explicitly designed for modern 64-bit architectures. The Core 2 lacks the CRC instruction introduced by the SSE 4.2 extension, which is the main reason Google wrote their hashes.

loeg8y ago

Look at XXH64.

bla28y ago

xxHash has a 64-bit version.

1 more reply

danesparza8y ago

This seems incredibly fast. Taking the benchmarks on the sites at face value, this seems like it's roughly twice as fast as xxHash.

I also appreciate this line in the README: "HighwayHash is not a general purpose cryptographic hash function (such as Blake2b, SHA-3 or SHA-2) and should not be used if strong collision resistance is required"

I am curious to know what the threshold for "strong collision resistance" is.

rurban8y ago

It's used for 32bit hashes in hash tables, so brute forcing this to create thousands of collisions on a desktop PC takes 2-4 min. Same for SipHash btw.

For hash tables you should not rely on the false security claims of these slow hashes anyway, rather implement proper collisions strategies to get rid of O(n) attacks.

fwessels8y ago

Check out the graph at https://github.com/fwessels/HashCompare that compares different hashing techniques.

And also we've done some predictions for collisions, see: https://github.com/fwessels/HashCompare/issues/1#issuecommen...

gpderetta8y ago

Not a cryptographer, but basically it must not be computability feasible (ie not just hard) to find a collision.

tromp8y ago

Note that performance is strongly dependent on message size. My Cuckoo Cycle proof of work hashes roughly a billion 8-byte messages with the 'cryptographically strong' SipHash in 4 seconds, for a single-core speed of 2000MB/s, while HighwayHash on longer 16-byte messages slows down to only 200MB/s (no figure provided for 8-byte messages).

j / k navigate · click thread line to collapse

13 comments

loeg8y ago

How does performance compare with XXhash, possibly the current leader in the non-cryptographic hash category?

rurban8y ago

XXhash is only fast with digest workloads, not hash tables. There the hash function needs to be fast and small, XXhash is too big and trashes the icache.

The current leaders are on my smhasher site, https://github.com/rurban/smhasher/

loeg8y ago

Thank you!

zuzun8y ago

loeg8y ago

Look at XXH64.

bla28y ago

xxHash has a 64-bit version.

1 more reply

danesparza8y ago

This seems incredibly fast. Taking the benchmarks on the sites at face value, this seems like it's roughly twice as fast as xxHash.

I am curious to know what the threshold for "strong collision resistance" is.

rurban8y ago

It's used for 32bit hashes in hash tables, so brute forcing this to create thousands of collisions on a desktop PC takes 2-4 min. Same for SipHash btw.

For hash tables you should not rely on the false security claims of these slow hashes anyway, rather implement proper collisions strategies to get rid of O(n) attacks.

fwessels8y ago

Check out the graph at https://github.com/fwessels/HashCompare that compares different hashing techniques.

And also we've done some predictions for collisions, see: https://github.com/fwessels/HashCompare/issues/1#issuecommen...

gpderetta8y ago

Not a cryptographer, but basically it must not be computability feasible (ie not just hard) to find a collision.

tromp8y ago

j / k navigate · click thread line to collapse