Incentive framework using Shapley value for BitTorrent-like systems

Abstract

BitTorrent is the dominating protocol in nearly all regions. Various reputation models and incentive mechanisms are proposed in recent years. However, many of them are designed for general peer-to-peer networks, only a few are designed for BitTorrent even though some models and mechanisms assert that they can be applied to BitTorrent-like systems. In this paper, we propose an incentive framework based on reputation history instead of tit-for-tat in BitTorrent. It is derived from the coalition games concept of Shapley value that will encourage selfish peers who seek to maximize their own profits to converge to Nash equilibrium. We show that this profit sharing framework exhibits several fairness properties that support the argument that this distribution of profit is desirable. Moreover, we improve SepRep reputation model and tailor it to the needs of BitTorrent protocol. In particular, we utilize the tracker of BitTorrent to process global reputation and trust values assisting the local values maintained by each peer.