Going Beyond Tit-for-Tat: Designing Peer-to-Peer Protocols for the Common Good
Ryan S. Peterson, Emin Gün Sirer · 2007
Peer-to-peer systems, in which participants pool their re-sources to accomplish their goals, have become ubiquitous. Since rational peers engage in strategic behavior, much past work has examined the design of mechanisms that incentivize peers to provide resources. The predominant design paradigm to date has been tit-for-tat, in which each peer benefits from every interaction. In this paper, we discuss the limitations of the tit-for-tat design paradigm and make the case for a new ap-proach based on seeking the globally optimal outcome known as the common good. Peer-to-peer (P2P) systems, in which participants simulta-neously act as both clients and servers, have become ubiq-uitous in recent years and dominate bandwidth consumed on the Internet. Compared to client-server systems that preceded them, peer-to-peer systems promise an unprecedented level of