You can get pretty far with a secure element. Server challenges with signed payload of nonce + current timestamp, and client verifies it and then re-signs the p

You can get pretty far with a secure element. Server challenges with signed payload of nonce + current timestamp, and client verifies it and then re-signs the payload. For something like a third-party coffee-ordering app, the economics of the usual attacks don't scale (either physically tearing apart the chip or exploiting a vulnerability in the first-party app).