I want to make a RFID access project for a small company. The project is not hard, I think.
Every employee will receive a RFID tag, with his ID number written in it, cryptographed.
I just want to make a first step, just like this: cryptograph and write a number (like 824576) in a RFID tag. I downloaded some cipher libraries, but couldn't make them work like I want.
Any ideas? Thank you!