How the digests are computed
The selected algorithm reads the input as raw bytes - UTF-8 for typed text, file bytes as stored - and pushes them through a one-way compression function. BLAKE2b works on 64-bit words with a 1024-bit block and 12 rounds; BLAKE2s on 32-bit words with a 512-bit block and 10 rounds; both descend from the ChaCha permutation. BLAKE3 reuses the BLAKE2s compression function at 7 rounds inside a binary Merkle tree, so multi-core machines can hash chunks in parallel.