Hashing
=======

**hircine** uses the `BLAKE3 cryptographic hash function
<https://github.com/BLAKE3-team/BLAKE3>`_ to compute hashes of archives and all
its contained files.

Whilst the latter files are hashed directly (i.e. their data is passed directly
to the hash function), the *ZIP* archives are not. Instead, **hircine**
calculates the hash of an archive by concatenating the hashes of *all* files
within it in archive order.

This means that changes to the archive files themselves will invalidate an
archive's hash, but changes to *ZIP* compression levels or other basic metadata
will not.