# blake2b_simd [](https://github.com/oconnor663/blake2_simd) [](https://crates.io/crates/blake2b_simd) [](https://github.com/oconnor663/blake2_simd/actions)
An implementation of the BLAKE2b and BLAKE2bp hash functions. See also
[`blake2s_simd`](../blake2s).
This crate includes:
- 100% stable Rust.
- SIMD implementations based on Samuel Neves' [`blake2-avx2`](https://github.com/sneves/blake2-avx2).
These are very fast. For benchmarks, see [the Performance section of the
README](https://github.com/oconnor663/blake2_simd#performance).
- 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](https://blake2.net/blake2.pdf), like adjustable
length, keying, and associated data for tree hashing.
- `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 hashes in parallel, matching the efficiency of
BLAKE2bp. See the [`many`](many/index.html) module.
# 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());
```