BitTorrent v1

v1 stores SHA-1 hashes for fixed-size pieces over the logical concatenation of all payload files. Multi-file boundaries do not reset piece hashing. Its info dictionary contains either a single length or an ordered files list.

The v1 info hash is SHA-1 over the exact bencoded source slice of the info dictionary. Re-serializing semantically equivalent data can therefore change identity when the source was not canonical.