Stable reputation management system in P2P networks: An evolutionary perspective

Abstract

In P2P networks, peers tend to “free-ride” on the contributions of others. Many reputation-based resource sharing mechanisms have been proposed to mitigate the problem of free riding. However, the evolutionary stability of these mechanisms that require peers to keep track of the reputations of other peers has not been investigated. We show that, without any extra benefit, systems with reputation-based incentive mechanisms are not evolutionary stable. We also show that if the fraction of peers that record reputation and reciprocate accordingly is above a certain threshold, then free riding can be controlled, and a reputation management system is beneficial only when the fraction of free riders is above a certain threshold. Furthermore, we show that imposing a round-based fee and dividing it among the peers as an incentive to keep track of reputation is an evolutionary stable strategy. In this process, we analyse all the possible equilibria in different settings of the system.