Trust and Cooperation in Peer-to-Peer Systems

Most of the past studies on peer-to-peer systems have emphasized routing and lookup. The selfishness of users, which brings on the free riding problem, has not attracted sufficient attention from researchers. In this paper, we introduce a decentralized reputation-based trust model first, in which trust relationships could be built based on the reputation of peers. Subsequently, we use the iterated prisoner’s dilemma to model the interactions in peer-to-peer systems and propose a simple incentive mechanism. By simulations, it’s shown that the stable cooperation can emerge after limited rounds of interaction between peers by using the incentive mechanism.