Biased Contribution Index: A Simpler Mechanism to Maintain Fairness in   Peer to Peer Network
  To maintain fairness, in the terms of resources shared by an individual peer, a proper incentive policy is required in a peer to peer network. This letter proposes, a simpler mechanism to rank the peers based on their resource contributions to the network. This mechanism will suppress the free riders from downloading the resources from the network. Contributions of the peers are biased in such a way that it can balance the download and upload amount of resources at each peer. This mechanism can be implemented in a distributed system and it converges much faster than the other existing approaches. 
Sateesh Kumar Awasthi and Yatindra Nath Singh
cs.NI