Co-utility - Self-enforcing collaborative protocols with mutual help.

Peer-to-peer scenarios are increasingly important in globalized information societies. To guide the interaction between (rational) agents in these P2P settings, self-enforcing collaborative protocols are desirable, so that agents have no motivation to deviate from them. Moreover, to increase social welfare and ensure the success of protocols, it would be desirable to make the collaboration between agents mutually beneficial. In this paper, we present the notion of co-utility, which refers to protocols in which mutual help is the best rational option to take, even for purely selfish agents. This concept is illustrated through several P2P scenarios, framed both in the information society and in the physical world, for which we present and discuss co-utile self-enforcing protocols.