Cisco wireless LAN Controller !!!
I think it is possible for you to set up a machine and user authentication that will require that you use a certificate to be able to connect to the wireless network that you are using.
Since you are using a Cisco controller, the certificate settings should be enabled in the Cisco router when you are configuring it, so that when a user wants to connect to the network they will have to verify their authenticity using the certificate you will have provided.
I am pretty surf the Cisco configuration manual should be covering a lot of how to go about that process and therefore I will advise that you check it out.
Hope this helps.