A Reputation System Resisting to Undercover Marketing

The rapid growth of communication networks such as the Internet and mobile networks have spurred the development of numerous online trading systems. The important point on the trade in such a community is the formation of trust with trading partners. System that stores the information about the trust and reputation and forms the online credit is a reputation system. However, malicious evaluator can enter an incorrect evaluation value to the reputation system. Such attacks are called the undercover marketing or the stealth marketing. In order to resist the attacks of the undercover marketing, reputation systems considering the evaluation capability of evaluators have been proposed. However, the system could not sufficiently respond to attacks that perform undercover marketing in pinpoint after having increased the level of evaluation capability. This paper proposes a novel algorithm to calculate the evaluation capability which reduces the influence of the value which is out of the daily trends. Simulation results show that the proposed method reduces the influence of the undercover marketing.