I do this all the time going SFO - JFK on United. You get an email with a link, opening that link on a phone shows a 2d barcode. It's quite simple and the scann

I do this all the time going SFO - JFK on United. You get an email with a link, opening that link on a phone shows a 2d barcode. It's quite simple and the scanners at security and the gate show your name and the agent checks that against your ID. I was expecting the system to be somewhat brittle but I've never had an issue with it.