Use an openid account from a single sign-on manager instead of RFID badges or keys on your access control.
We all have smartphones. Improve authentication speed. No specific badges or keys anymore.
Keep a hand on authorizations, define fine rules for each user.
Poximity is the best security. Scan a QRCode on the smartphone screen instead of type a 4 digit code, like you do in the airport with your flight registration ! You can also use bluetooth LE ; each smartphone has bluetooth builtin, so everyone can use it.
There nothing to prove : OAuth2 is the best authentication protocol and the most use on the internet. Use this protocol for your own access control.