QR-based-login

Some of my friends participated in a hackathon where they wanted to propose a product which was a wrist band with QR code for kids and elderly people so that if they get lost there details could be found by scanning the QR code, they were able to work out the froont end, but they couldn't implement the backend, so after the hackathon, we had a dicussion on the project and I decided to implement the back end