> for some reason, passes are cryptographically signed, and they have to be signed with a key known to one of Apple’s certificate authorities. Cryptographically signing these files makes some sense when you consider that passes were designed to get automatic updates from their vendors; for example, your boarding pass for a flight reflecting gate changes or changing your seat assignment.

How does this make sense? There’s a perfectly well supported system for doing this: HTTPS.

Maybe Apple wants passes to be verifiable by the phone offline instead of just when updated? This still seems silly — a malicious actor could replace a pass instead of updating it.