I would like to develop an application that can connect to server and uniquely identify clients then give them permissions to run a specific query on server's database. How can I identify clients in a unique way. Is MAC address reliable enough? or should I use something like CPU id or something else?
clarification : I do not what to create a registration code for my app. As it's suppose to be a free application. I would want to detect each client by an id and decide which one could have the permissions to run a specific method on server or not.