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Why BLAKE2 for hashing? "BLAKE2 is a cryptographic hash function faster than MD5, SHA-1, SHA-2, and SHA-3, yet is at least as secure as the latest standard SHA-3. BLAKE2 has been adopted by many projects due to its high speed, security, and simplicity."

node-blake2 provides a stream-compatible blake2b, blake2bp, blake2s, and blake2sp Hash and KeyedHash for Node.js.

node-blake2 has been tested to work with the following compilers and platforms:

Compiler Operating System Architecture
GCC 8.3.0, 10.2.0, 11.2.0, 12.2.1 GNU/Linux Gentoo x86_64
LLVM clang 11.1.0, 13.0.0, 15.0.7 GNU/Linux Gentoo x86_64
GCC 5.4.0 GNU/Linux Ubuntu 16.04 x86_64
LLVM clang 11.1.0 OpenBSD 7.0 x86_64
Apple LLVM clang 9.1.0 macOS 10.13 x86_64
Visual Studio 2019 Windows 11 x86_64
Visual Studio 2015 Windows 10 x86_64
GCC 10.2.1 GNU/Linux RPi OS 2021-10-30 armv7l Cortex-A53 RPi 3
GCC 10.2.1 GNU/Linux Debian 11.2 aarch64 Cortex-A57 QEMU
GCC 9.3.0 GNU/Linux Ubuntu 20.04 aarch64 Cortex-A72 RPi 4
Apple LLVM clang 12.0.5 macOS 12 aarch64 Apple M1

Prerequisites for building on Windows

Visual Studio Build Tools.

Python is required by node-gyp.

The Node.js Windows installer can automatically install Python and Visual Studio build tools.


In your project, run:

npm install blake2 --save

or install from the GitHub repo:

npm install vrza/node-blake2 --save


Unkeyed BLAKE2b

var blake2 = require('blake2');
var h = blake2.createHash('blake2b');

blake2.createHash works like node's crypto.createHash.

Keyed BLAKE2b

var blake2 = require('blake2');
var h = blake2.createKeyedHash('blake2b', Buffer.from('key - up to 64 bytes for blake2b, 32 for blake2s'));

blake2.createKeyedHash takes a key argument like crypto.createHmac. Although it is not an HMAC, a keyed hash serves the same purpose.

Important notes

  • blake2.create{Hash,KeyedHash} support algorithms blake2b, blake2bp, blake2s, and blake2sp.
  • Data passed to .update on blake2.{Hash,KeyedHash} must be a Buffer.
  • Keys passed to blake2.createKeyedHash(algo, key) must be a Buffer.
  • Just as with crypto.Hash, .digest() can only be called once.

With streams

This works exactly like it does with crypto.Hash. See b2sum.js.

Custom digest length

BLAKE2 can generate digests between 1-64 bytes for BLAKE2b and 1-32 bytes for BLAKE2s. Pass digestLength as an option to use a digest shorter than the default (maximum length):

var blake2 = require('blake2');
var h = blake2.createHash('blake2b', {digestLength: 16});
h.digest(); // Returns a Buffer with 16 bytes

or with a key:

var blake2 = require('blake2');
var h = blake2.createKeyedHash('blake2b', Buffer.from('my key'), {digestLength: 16});
h.digest(); // Returns a Buffer with 16 bytes

Note that BLAKE2 will generate completely different digests for shorter digest lengths; they are not simply a slice of the default digest.

Copying a hash object

You can call .copy() on a Hash or KeyedHash, which will return a new object with all of the internal BLAKE2 state copied from the source object.

var blake2 = require('blake2');
var h = blake2.createHash('blake2b');

// Call .copy() before .digest(), because .digest() finalizes internal state
var j = h.copy();

// h is unaffected by updates to j


Known issues

  • On Windows, node-blake2 requires enabling AVX instructions as a workaround for the way the upstream build preprocessor detects support for SSE2.