Patent ID: 7801952

Claim:
A method for determining whether a client is authentic and permitted to participate in a network-enabled service provided by a server, the method comprising: maintaining at a server a plurality of challenges, each of said plurality of challenges being a server-based challenge usable by the server to detect one or more modifications on a client device that allow a user of the client device to cheat when playing the at least one online game; receiving a request from the client device to participate in a particular network-enabled online game; selecting a one of the challenges and transmitting the challenge to the client gaming device, the challenge including encoded machine executable instructions that, when executed by the client device, cause the client device to compute a response to the challenge, the response being related to and indicative of either the lack or existence of the one or more modifications on the client device; receiving the response from the client device; analyzing the response to determine whether the response received from the client matches an expected response indicative that the client device has not been modified to allow the user to cheat in the at least one online game; when the response received from the client device does not match the expected response for a client device that has not been modified, denying the request from the client and identifying the client as a device which is to have all future requests denied, thereby preventing the client from future play of the network enabled online game.