A Conceptual Incentive Mechanism of P2P File Sharing Systems Based on Game Theory

Selfish adaptive peers are widespread in Peer to Peer(P2P) file sharing systems, whose actions greatly reduce the system´s performance. So how to maintain significant levels of cooperation to encourage collaborative is an important aspect of P2P research. In this paper, the cooperation models of P2P file sharing systems are constructed based on the Prisoner´s Dilemma Game (PDG) and the Snowdrift Game (SG), which add a new viewpoint to P2P file sharing systems understanding. In particular, the performances of the two models are investigated in three aspects: the frequency of cooperation, the equilibrium-time, and the full completion time, which indicate that both the PDG and the SG can effectively motive cooperation against free riding. In addition, the SG performs better than the PDG in promoting peers to share what they have, which suggests theoretic guidelines to design a good incentive mechanism in the future.