| With the rapid development of Internet application,the traditional business transaction environment has been greatly changed,and the Internet as the medium to provide users with online services has been rapidly popularized.Online service reputation is the accumulated result of various online service credit behaviors,which can assist users to select high-quality services.In order to improve their influence or reduce the opponent,a malicious user or online service provider may manipulate,attack the reputation system,the distortion of the credibility of online services,users run the risk of not being able to select services that meet their preferences when their reputation is manipulated to mislead their judgment.In order to obtain improper benefits,some managers of reputation system control service reputation by deleting or adding users and services.The existing work focuses on the manipulation of reputation by ordinary users or online service providers,but lacks measures to prevent the management of reputation system from manipulating service reputation through technical means.In addition,considering that different users’ evaluation criteria for different online services are inconsistent,user evaluation information cannot be compared,which makes the reputation measurement method based on the same evaluation criteria lack rationality.For this reason,an online service reputation anti-manipulation mechanism based on Fallback social choice theory is proposed.Firstly,considering the inconsistency of user evaluation criteria,the method obtains the ordinal preference of all users to online service instead of rating as input.Secondly,the list of user-service scores was obtained according to the ordinal number preferences of all users,and the online service reputation vector satisfying Fallback absolute majority threshold condition was obtained.Then the online service reputation manipulation is modeled as a question to determine whether a certain service can become the most reputable service through control.Finally,Fallback method is proved to be anti-manipulation,that is,the control problem is fixed parameter intractable.The theoretical analysis shows that Fallback method satisfies the fairness,monotonicity,non dictatorship and anti-manipulation of online service reputation evaluation,and the experiment further verifies fairness,monotonicity,and the effectiveness of anti-manipulation.The experimental results show that this method can effectively prevent the manipulation of managers who can grasp users’ preferences within the reputation system.Finally,based on the Fallback online service reputation anti-manipulation mechanism proposed in this paper,the prototype system of online service reputation anti-manipulation mechanism based on Fallback social choice theory is designed and implemented,demonstrating the effect of Fallback prevention and manipulation in a simple and visual way. |
