Incentive mechanisms for cooperation in peer-to-peer networks

Abstract

Peer-to-peer networks have recently emerged as a solution for the well-known problems of scalability imposed by client-server architecture. In these networks, the roles of serving and being served are not always asymmetrical, that is to say, one selfsame participant may at times cooperate and at others enjoy the cooperation of others. Moreover, quite often the figure of central authorities or servers is lacking, which implies an autonomy for the entities to decide on the patterns of behavior they will display, with the power to act selfishly, lavishly, selflessly or quite simply fairly, that is to say, cooperating only when possible. The feasibility of peer-to-peer systems is strongly based on the premise of cooperative behaviors. Moreover, the concept of synergy is fundamental to such systems, that is, it is expected to exploit the local resources of the participants so that their joint utilization results in a better result than the sum of the respective individual utilization. Thus, leaving the decision to cooperate or not under the sole responsibility of the participants, without any outside influence or incentive, entails putting at risk not only the system's efficiency, but also its very feasibility. This chapter sets out a study of incentive mechanisms for cooperation. The chapter place greater emphasis on the different incentive patterns used in common by the various incentive schemes in peer-to-peer networks. © 2010 Springer Science+Business Media, LLC.