Abstract: Trust measure is the basis of trust mechanism. Now the trust mechanism is facing the threat that malicious users manipulate the reputation. I}he trust measure model based on the social factors of users and their behavior expands the traditional trust mechanism. It describes and analyses the characters of malicious users and their behavior by the social factor,which reflects the essential of user and behavior. This model also adds the audit process in order to correct the reputation under the attack, so it can guarantee the credibility of trust measure in distributed Environment. Simulation experiments show that this model can effectively react to the reputation manipulation attack by the malicious users.

Key words: User behavior, Trust measure,Trust mechanism