3.5 BLAKE Algorithm

The BLAKE algorithm is based on the ChaCha stream cipher. When the BLAKE2 algorithm calculates a hash without a key, it is called an unkeyed hash. The BLAKE2 algorithm can use an optional key ranging from 1 to 64 bytes; if no key is used, then key length is 0. Key length up to 32 bytes for BLAKE2s and 64 bytes for BLAKE2b. Digest length 1 to 32 bytes for BLAKE2s and 1 to 64 bytes for BLAKE2b.