Yeah, it could be digitally signed for offline verification. But I’m doubtful there’s enough standardization going on that corporations are integrating signature verification right there in the POS system. They’d need the public keys from the government, presumably. That doesn’t sound too difficult but also, setting up a process to get that info for all 50 states would probably be a mess. Do the states even sign the info to start — that’s another question.

I think the infrastructure can be deployed. Though, I get the impression it would take more coordination than we actually see here in the wild.