(click for full size)The important thing to note about the QR code approach is that it is a digitally signed credential. That means it is worthless without showing a driver's license that matches the name embedded in the QR code ( part of the data). The data is signed by some authority and it is still TBD what authority signatures will be acceptable. If this becomes standardized I will create a self-signed authority (e.g. Palmer's Vaccination Authority) and sign my own credential to try it out somewhere.
If that works I'll be able to sign any number of credentials, and write a simple app to display the QR. If it doesn't work I'll have to copy somebody's QR and display that with their name. The bouncer will scan it and see their name. I will have to say yes I am Joe Shmoe but left my drivers license at home and took Uber.
I can think of another interesting way to monkey the system but I'll have to do a little research. This is truly a "papers please" paradigm that has to be fought in every way possible.