A Trust Model Based on Subjective Logic

In order to resolve the trust problem due to the opening, the dynamics, the anonymity and uncertainty of p2p system, this paper proposes a new p2p trust model by analyzing and improving the subjective logic, a new trust quantification formula with the negative events effect and the time effect is given, and a definition of risk is also presented, By doing this, we can evaluate the trust relationships between peers more precisely and prevent the hidden security dangers of cooperative cheat and slander more effectively, thus can resolve security problems exist in p2p environment more effectively.