What I don't get is why these locks all seem to do real time connections, when we have public key crypto! The "key" should just be a certificate signed by the o

What I don't get is why these locks all seem to do real time connections, when we have public key crypto! The "key" should just be a certificate signed by the owner's, which could then by verified offline by the lock. You'd just need a periodical sync to get revocations (if you needed to kick someone off the place prematurely). It's old, well established tech!