PET: A PErsonalized Trust Model with Reputation and Risk Evaluation for P2P Resource Sharing

Building a good cooperation in the P2P resource sharing is a fundamental and challenging research topic because of peer anonymity, peer independence, high dynamics of peer behaviors and network conditions, and the absence of an effective security mechanism. In this paper, we propose PET, a personalized trust model, to help the construction of a good cooperation, especially in the context of economic-based solutions for the P2P resource sharing. The trust model consists of two parts: reputation evaluation and risk evaluation. Reputation is the accumulative assessment of the long-term behavior, while the risk evaluation is the opinion of the short-term behavior. The risk part is employed to deal with the dramatic spoiling of peers, which makes PET differ from other trust models that based on the reputation only. This paper contributes to first modeling the risk as the opinion of short-term trustworthiness and combining with traditional reputation evaluation to derive the trustworthiness in this field.