You can't spoof them with you fingers Well, okay, but I could trivially present a custom application for stamping that would record them to make my own stamp.

You can't spoof them with you fingers Well, okay, but I could trivially present a custom application for stamping that would record them to make my own stamp. That's probably fine for loyalty programs, but is most certainly not fine for EMR. A dynamic QR code might be clunkier, but a static key will never be secure. (or sniffing the real application from the background by jailbreaking)