BLAKE2 is a high-speed, cryptographically secure hash function defined in RFC 7693 that outperforms MD5 and SHA-2 while matching SHA-3 security.
BLAKE2 is an optimized cryptographic hash function designed by Jean-Philippe Aumasson, Samuel Neves, Zooko Wilcox-O'Hearn, and Christian Winnerlein. Standardized in RFC 7693, BLAKE2 is an evolution of the SHA-3 finalist BLAKE, engineered to deliver exceptional throughput on modern microprocessors while providing cryptographic security equal to or exceeding SHA-256, SHA-512, and SHA-3.
Generate and compare BLAKE2b, SHA-256, SHA-512, and HMAC digests instantly in your browser with our client-side Hash Generator tool.
| Specification | BLAKE2b (64-bit Architecture) | BLAKE2s (8 to 32-bit Architecture) |
|---|---|---|
| Standard Reference | IETF RFC 7693 | IETF RFC 7693 |
| Native Word Size | 64-bit words ($u64$) | 32-bit words ($u32$) |
| Max Digest Length | Up to 512 bits (64 bytes) | Up to 256 bits (32 bytes) |
| Internal Block Size | 128 bytes (1024 bits) | 64 bytes (512 bits) |
| Rounds of Compression | 12 rounds | 10 rounds |
| Core Primitive | Modified ChaCha permutation | Modified ChaCha permutation |
| Keyed MAC Mode | Native (Built-in key prefix) | Native (Built-in key prefix) |
| Tree Hashing Support | Supported (Parallel tree modes) | Supported (Parallel tree modes) |
Traditional hash functions like MD5, SHA-1, and SHA-2 utilize bitwise operations and additions that create sequential dependency stalls in CPU instruction pipelines.
BLAKE2 modifies Daniel J. Bernstein's ChaCha stream cipher permutation to process data in 8 parallel working state registers ($v_0 \dots v_{15}$). The compression function $G$ mixes 4 words simultaneously using basic vector-friendly operations:
G(a, b, c, d, x, y):
a = a + b + x
d = (d ⊕ a) >>> 32
c = c + d
b = (b ⊕ c) >>> 24
a = a + b + y
d = (d ⊕ a) >>> 16
c = c + d
b = (b ⊕ c) >>> 63
This diagonal and column round structure maps cleanly to SIMD instruction sets (AVX2, AVX-512, ARM NEON), allowing 64-bit CPUs to compute digests at over 3.08 cycles per byte—faster than legacy, insecure MD5.
| Algorithm | Digest Size | Collision Status | Throughput (Cycles/Byte) | Length Extension Immune? |
|---|---|---|---|---|
| MD5 | 128 bits | Broken ($2^{16}$ practical) | ~5.5 | No |
| SHA-256 | 256 bits | Unbroken | ~12.5 | No |
| SHA-512 | 512 bits | Unbroken | ~8.0 | No |
| SHA-3-256 | 256 bits | Unbroken | ~10.5 | Yes (Sponge) |
| BLAKE2b-512 | 512 bits | Unbroken | ~3.1 (Ultra-fast) | Yes (Root padding) |
| BLAKE3 | 256 bits | Unbroken | ~0.7 (Tree SIMD) | Yes (Tree mode) |
import crypto from 'node:crypto';
// Compute a 256-bit BLAKE2b hash in Node.js
export function computeBlake2b256(data) {
return crypto
.createHash('blake2b512')
.update(data, 'utf8')
.digest('hex')
.slice(0, 64); // 256-bit representation
}
console.log(computeBlake2b256('DevFlow Tools'));
Yes. BLAKE2 uses a tree-based parameter block and explicit final-block indicator flags in its compression function. This makes it structurally impossible for an attacker to append data to an existing hash state, eliminating length extension vulnerabilities without requiring a separate HMAC construction.
BLAKE2b is optimized for 64-bit architectures (such as x86_64, Apple Silicon, and ARM64 servers) and can output digests up to 512 bits. BLAKE2s is optimized for 8-bit, 16-bit, and 32-bit platforms (such as microcontrollers, ARM Cortex-M, and IoT devices) and produces digests up to 256 bits.
BLAKE3 (released in 2020) is the successor to BLAKE2. It implements a full Merkle tree structure, allowing arbitrary dynamic SIMD and multi-core parallelism. BLAKE3 is approximately 4x faster than BLAKE2b on modern CPUs while providing 128-bit security level across all tree modes.
Free, browser-based utilities to test, generate, and inspect BLAKE2 Cryptographic Hash Function (BLAKE2b & BLAKE2s) payloads directly.