Research On The Cheating Problem For MMOG Based On P2P

With the rapid development of computer technology and the advancement of people's entertainment requirement in recent years, MMOG (Massively Multiplayer Online Games) has attracted more and more scholars, corporations and players, and has become a hotspot study problem in the international computer discipline. Compared with the traditional computer games, the online games has implemented the share of game state through the internet, and can response to the game events rapidly, which can enhance the interaction, simulation and competition characteristics of it. The entertainment characteristic of MMOG attracts large numbers of players and the competition urges players to obtain higher goal, which brings more and more security problems. The appearance of MMOG not only changes the rule of computer games, but also changes the security requirement in substance.There are mainly two kinds of security problems in MMOG, the security problems exist in the traditional network applications and the security problems peculiar to MMOG which named cheating. The traditional MMOG based on C/S model has a better security, but this centralized architecture has the server bottleneck and other limitations. The P2P architecture is a distributed model that can solve the limitations of the C/S architecture, but its open characteristic also aggravates the security problem. Cheating not only decreases the playability of games, but also threatens the game industry. Therefore, the study of cheating problems in MMOG has significant academic meaning and actual meaning.The updated security strategies in MMOG are cheat-proofing protocol and cheat-detection algorithm. These strategies can solve some specific cheating, but the security characteristic and adaptability characteristic are not satisfying. After analyzing the problems and limitations of the existing security mechanisms, this dissertation mainly accomplishes those works as follows:1 Do taxonomy to the MMOG cheatingA number of authors have attempted to define a framework for classifying and understanding online game cheating. Unfortunately, those categorizations are inaccurate, and they only cover a small number of types of cheats. Many cheats cannot fit into any of these categories. This dissertation sorts the online game cheatings that have happened or might happen.2 Propose an adjusting frame duration mechanism of NEO based on two-sided Hypothesis TestingFor the purpose of improving the adaptability of communication protocol, NEO protocol has a frame duration changing dynamically mechanism. But the changing is achieved by player voting, which can influence the game responsibility. This dissertation delivers this voting power to the game engine, and the ending hosts do statistic of the update arriving duration changing using two-sided Hypothesis Testing, then accomplishes the adjusting. Using two-sided Hypothesis Testing can figure out the changing of time duration precisely and the adaptability of game is enhanced.3 Propose a cheat-detection mechanism based on fuzzy trust managementThe existing cheating detection mechanism base on predefinition parameter threshold judges whether a player is honest or not with the fixed game parameter threshold levels. The false decision ratio of it is quite high because of the fixed parameter thresholds deployed in the cheating detection mechanism. This dissertation introduces the trust management into the cheating detection mechanism, and proposes a FuzzyTD algorithm. The algorithm updates player's reputation vector calculated from his history data of the game, and then adjusts the game parameter thresholds further. Therefore, the false decision ratio reduces.The experiment results show that the security and capability of the algorithms proposed in this dissertation are much better and the prospective demand is achieved in general.