The "Value" of Reputation in Peer-to-Peer Networks

Peer-to-peer networks need to have self-organization properties because of the lack of a centralized authority. This implies that nodes should self-manage and cooperate to sustain the availability of the resources in the system. In this context reputation management schemes have been proven in the past to be a useful tool to foster cooperation. In this paper we discuss the importance for a node to build and use its reputation value. We propose a game-theoretical framework, based on the generalized form of the Iterated prisoner´s dilemma, to model the interactions of rational and selfish nodes in distributed systems. We study how a node takes into account the change of its reputation when deciding its behaviour in a transaction and discuss the Nash equilibrium in the system. Then, we also simulate nodes´ interactions under different strategies to analyze how cooperation and reputation evolve in the system.