Characterizing Economic and Social Properties of Trust and Reputation Systems in P2P Environment

Considering the fact that P2P (Peer-to-Peer) systems areself-organized and autonomous, social-control mechanism (like trust andreputation) is essential to evaluate the trustworthiness ofparticipating peers and to combat the selfish, dishonest and maliciouspeer behaviors. So, naturally, we advocate that P2P systems thatgradually act as an important information infrastructure should bemulti-disciplinary research topic, and reflect certain features of oursociety. So, from economic and social perspective, this paper designsthe incentive-compatible reputation feedback scheme based on well-knowneconomic model, and characterizes the social features of trust networkin terms of efficiency and cost. Specifically, our framework has twodistinctive purposes: first, from high-level perspective, we arguetrust system is a special kind of social network, and an accuratecharacterization of the structural properties of the network can be offundamental importance to understand the dynamics of the system. Thus,inspired by the concept of weighted small-world, this paper proposesnew measurements to characterize the social properties of trust system,that is, high global and local efficiency, and low cost; then, fromrelative low-level perspective, we argue that reputation feedback is aspecial kind of information, and it is not free. So, based on economicmodel, VCG (Vickrey-Clarke-Grove)-like reputation remunerationmechanism is proposed to stimulate rational peers not only to providereputation feedback, but truthfully offer feedback. Furthermore,considering that trust and reputation is subjective, we classify thetrust into functional trust and referral trust, and extend the referraltrust to include two factors: similarity and truthfulness, which canefficiently reduce the trust inference error. The preliminarysimulation results show the benefits of our proposal and the emergenceof certain social properties in trust network.