Semi-Lock: An Efficient Cheat-Proof Synchronization Mechanism for Peer-to-Peer Game Systems

Abstract. With more and more online game players having access to broadband Internet connections and high performance computers, peer-to-peer architecture offers an attractive solution for online multiplayer game design. However, message synchronization and cheat proof are two major challenges in implementing a fully distributed peer-to-peer game system. In this paper, a novel scheme, called Semi-Lock, is proposed to support message synchronization and prevent protocol level cheats for such systems. In Semi-Lock, peers encrypt each message by using cryptographically secure one-way hash function. A two-step validation is applied at destination peers to verify the integrity and correctness of the received messages. Trace driven simulations are conducted to verify the performance of our proposed scheme. Simulation results show that it significantly outperforms existing algorithms in terms of message latency and message synchronization ratio, with only little extra computational overhead on each peer.