HashesAcceptable
BLAKE2 and BLAKE3
Cryptographic hash functions
How it works
BLAKE2 descends from BLAKE, a SHA-3 competition finalist, and was tuned for speed in software while keeping a high security margin. BLAKE3 goes further, using a tree structure so large inputs can be hashed in parallel. Both support keyed hashing directly, so they can act as a MAC.
Sizes: BLAKE2b up to 512-bit output, BLAKE2s up to 256-bit; BLAKE3 256-bit default, extendable
Status: Secure and fast, but not FIPS-approved.
Strengths
- Very fast in software, often faster than MD5 while remaining secure.
- Built-in keyed mode avoids the need for HMAC.
- BLAKE2b is used inside Argon2 and in many modern tools.
Weaknesses and known attacks
- Not FIPS-approved, so excluded from many regulated environments
- Too fast for password storage on their own
Use it for
- File integrity, content addressing and fast checksums with security
- Keyed hashing in non-FIPS software
Don't use it for
- FIPS-only systems
- Password storage on its own
Exam tip
BLAKE2 and BLAKE3 are less likely on exams than SHA-2 and SHA-3; know them as fast, secure, non-FIPS hashes.