Going Beyond Tit-for-Tat: Designing Peer-to-Peer Protocols for the Common Good

Peer-to-peer systems, in which participants pool their resources 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 approach based on seeking the globally optimal outcome known as the common good.