Research Of Access Control Scheme And Security Of Protocol Layer Of Voronoi Based P2P Massively Multiplayer Online Game

With the information technology development and the change of the people's way to entertainment, more and more people join in different online games which has developed into an indursty that makes millions of dollars per year nowadays. But the scalability of Massively Multiplayer Online Games (MMOGs) faces inherent limits caused by the traditional client-server architecture, so researchers identify an emerging research direction that uses peer-to-peer (P2P) network technology to realize more scalable and affordable MMOGs. In this thesis, the principle of this technology is presented and compared with the traditional C/S based MMOGs to indicate its advantages firstly; secondly, some of the famous P2P Based MMOGs technology are analysed and compared; finally, the most promising Voronoi based MMOGs is choosed as the security study base of the thesis.Although P2P architecture has many advantages, but it has serious security problems on a large scale commercial spread compared with the C/S architechure. P2P based MMOGs not only has the common security problems of the traditional online games, but also has some special security needs. For example it's hard for the operators to charge and implement acess control in P2P based MMOGs. These problems are detailedly discussed in chapter 3, In this chapter, a algorithm and a communication flow for the nodes to make link are designed firstly, then a new dynamic password based mutual identity authentication scheme is designed, finally, an scheme that uses software based access control token tchnology combines with the fetures of the Voronoi based P2P online games is designed to solve the charging problem. The integrated access control scheme is implemented in chapter 5 and the experiment shows this scheme can effectively solve the problem.Beside the access control problem, security risk also exist in the protocol layer in P2P online games, the reason is that all of the game logic is implemented inside the client software and the server can't monitor and control the action of the player, thus, if the attacker succeed to cheat in protocol layer, then the principle of fair play are broken. In chapter 4, protocol layer security problems are studied, then the security performance of NEO protocol and SEA protocol are analyzed, this thesis learns from their strong points to offset their weakness, finally, an secure communication protocol which called VSEO that can be used in Voronoi based P2P online games is designed. in chapter 5, The VSEO protocol is implemented into the VAST open source project, Theoretic analysis shows this protocol can effectively resist protocol layer cheating and the simulation result shows it has little affect on game performance.