README.md

blake2b_simd
blake2s_simd

An implementation of the BLAKE2(b/s/bp/sp) family of hash functions with:

• 100% stable Rust.
• SIMD implementations based on Samuel Neves' blake2-avx2. These are very fast. See the Performance section below.
• Portable, safe implementations for other platforms.
• Dynamic CPU feature detection. Binaries include multiple implementations by default and choose the fastest one the processor supports at runtime.
• All the features from the the BLAKE2 spec, like adjustable length, keying, and associated data for tree hashing.
• The blake2 command line utility, published as the blake2_bin crate, with command line flags for all the BLAKE2 variants and associated data features.
• no_std support. The std Cargo feature is on by default, for CPU feature detection and for implementing std::io::Write.
• Support for computing multiple BLAKE2b and BLAKE2s hashes in parallel, matching the efficiency of BLAKE2bp and BLAKE2sp. See the many module in each crate.

Example

use blake2b_simd::{blake2b, Params};

let expected = "ca002330e69d3e6b84a46a56a6533fd79d51d97a3bb7cad6c2ff43b354185d6d\
                c1e723fb3db4ae0737e120378424c714bb982d9dc5bbd7a0ab318240ddd18f8d";
let hash = blake2b(b"foo");
assert_eq!(expected, &hash.to_hex());

let hash = Params::new()
    .hash_length(16)
    .key(b"The Magic Words are Squeamish Ossifrage")
    .personal(b"L. P. Waterhouse")
    .to_state()
    .update(b"foo")
    .update(b"bar")
    .update(b"baz")
    .finalize();
assert_eq!("ee8ff4e9be887297cf79348dc35dab56", &hash.to_hex());

An example using the included blake2 command line utility:

$ cargo install blake2_bin
$ echo hi | blake2 -sp
49228db2a2fa8d25e8b3b2aca5a70234c71490516eaca9cba007b27d59c532b8

Performance

To run small benchmarks yourself, run cargo +nightly bench. If you have OpenSSL, libsodium, and Clang installed on your machine, you can add --all-features to include comparison benchmarks with other native libraries.

The benches/bench_multiprocess sub-crate runs various hash functions on long inputs in memory and tries to average over many sources of variability. Here are the results from my laptop for cargo run --release (lower is better):

• Intel Core i5-8250U (Kaby Lake Refresh)
• libsodium version 1.0.18
• OpenSSL version 1.1.1.d
• rustc 1.40.0
• clang 9.0.1

╭─────────────────────────┬──────────╮
│ BLAKE3                  │ 0.95 cpb │
│ blake2s_simd many::hash │ 1.31 cpb │
│ blake2s_simd BLAKE2sp   │ 1.32 cpb │
│ blake2b_simd many::hash │ 1.43 cpb │
│ blake2b_simd BLAKE2bp   │ 1.44 cpb │
│ blake2b_simd BLAKE2b    │ 2.81 cpb │
│ libsodium BLAKE2b       │ 3.07 cpb │
│ OpenSSL SHA-1           │ 3.51 cpb │
│ blake2s_simd BLAKE2s    │ 4.66 cpb │
│ OpenSSL SHA-512         │ 5.11 cpb │
╰─────────────────────────┴──────────╯

Links

• v0.1.0 announcement on r/rust
• v0.5.1 announcement on r/rust
• the BLAKE3 hash function, an evolution of BLAKE2