Blake3
cryptographic hash function. Merkle tree internally, parallelizable, 2 GB/s on a single core. designed by Jack O'Donnell, Samuel Neves, Jean-Philippe Aumasson, and Zooko Wilcox-O'Hearn (2020)
based on the Blake2 compression function (which descends from ChaCha). the Merkle tree structure enables unlimited parallelism and verified streaming — the same chunk can be hashed independently on different cores
used by iroh for content addressing and verified streaming (bao protocol). radio replaces Blake3 with Hemera because proving a Blake3 hash inside a stark costs 50,000–100,000 constraints versus ~736 for Hemera. the throughput tradeoff (2 GB/s vs ~50–100 MB/s on CPU) is acceptable because proving cost dominates in a system where every operation must be verifiable