Hacker impersonates my computer.

Hello, one of my friends has recently picked up cracking my Craftbukkit minecraft server for fun. Basically, he explains that he does something with an ip adress and a cheat engine and the server thinks that his computer is my computer, so he has access to all admin commands.

In case banning is not an option, any ideas how I can protect the admin commands? Is there some way to password-protect them?

 

I don't think that this is possible as the server would assign one player a unique ID, which is secret between the Minecraft login servers & your PC. The only way he could get admin is if you were running an offline server, and then someone changed their offline name to yours.

 

Do all client-server messages get identified with this secret ID?