ABSTRACT
The highly flexible features of P2P computing such as a dynamic population (users come and go asynchronously at will), dynamic topologies (it is impractical, if not impossible, to enforce a fixed communication structure), and anonymity, come at a significant cost-autonomy, by its very nature, is not always in harmony with tight cooperation. Consequently, inefficient or lack of cooperation could lead to undesirable effects in P2P computing. Among them the most critical one is “free-riding” [Feldman and Chuang, 2005,Ramaswamy and Liu, 2003] behavior. Loosely speaking, free-riding occurs when some users do not follow the presumed altruistic cooperation rules such as sharing files voluntarily, sharing bandwidth voluntarily, or sharing energy voluntarily, so as to benefit the whole community.
