A contribution-based incentive mechanism for P2P file sahring systems

In P2P file sharing systems, behaviours of free riders and malicious peers cause negative impact on the robustness and availability of these systems. However, most existing incentive schemes only consider behaviours of free riders or malicious peers, thus fail to effectively enhance performances of these systems. In this paper, a contribution-based incentive mechanism with considering both behaviours is proposed. Firstly a contribution management scheme is presented to identify peers with different behaviours. Then a contribution value-based service policy is given to provide differentiated service to peers with different behaviours in order to motivate cooperation among peers. Simulation results confirm the ability of our proposed incentive mechanism to effectively identify both free riders and malicious peers, and punish them by reducing the level of service provided to them.