Topic: A dynamic NFC tag does it exist?
I'm looking for a dynamic NFC tag that is able to dynamically change its content or a NFC tag that is able to talk SNEP.
Don't answer "a smartphone", that's not my target.
My target is to offer a simple way of authentifying someone that doesn't have a NFC handset (because it's expensive or because the battery is empty, etc).
The idea is to use the NDEFormat to exchange data based on a challenge sent by an initiator (the reader that stands in the wall near the door).
The tag then computes a NDEF with a specific field (to be defined) whose content is a result of a cryptographic function applied to the challenge (nothing new here: windows, Kerberos, etc have been working this way for a couple of years).
The reader then reads this NDEF and applies the same cryptographic function to its challenge: if they match the door opens else the door keeps closed.