Abstract-One of the key challenges in peer-to-peer networks is the design of incentives to encourage peers to share their resources. Incentives are necessary in order to exploit the full potential of these systems. The tit-for-tat incentive scheme, as used in BitTorrent for example, has proven to be a successful approach in P2P file sharing systems, where peers have direct relations and share the same kind of resources. However, in P2P systems where different kind of resources are shared between peers with non-direct relations, the design of incentives remains a challenge. In this paper, a large-scale, fully decentralized P2P collaboration network is shown, where peers share not only bandwidth and storage space, but also contribute by editing articles and voting for or against changes. A new incentive scheme is proposed which supports non-direct relations and provides incentives for sharing different kind of resources. The incentive scheme is based on a reputation system that assigns a reputation value to every peer reflecting its previous behavior in the network. Based on this value, the service level is differentiated, i.e. the higher a peer's reputation the better the quality of service it can get from the network. The service differentiation has been analyzed and simulated with rational, irrational and altruistic peers based on game theory concepts. Peer-to-peer (P2P) networks have received much attention in the past because they have many advantages over client-server architectures, including fault tolerance, higher scalability, and less maintenance costs. However, one of the drawbacks of P2P networks is that participants tend not to share their resources, which can result in a serious loss of performance [1], [8] . Thus, in order to encourage peers to share their resources there needs to be an incentive scheme that rewards cooperation and punishes freeriding. BitTorrent [4] is a prominent example of a P2P file-sharing system that includes a solid incentive scheme called tit-for-tat (TFT). TFT provides incentives to share resources for peers with direct relations and resources of same kind. Two peers are in a direct relation if both peers demand and supply resources of the same kind. The TFT scheme is useful for applications with many direct relations. This is typically the case for P2P file-sharing systems, especially when sharing popular files.
The work in REF studies an incentive mechanism for resources that are shared among peers with non-direct relations and differentiate the service level based on every peer's previous behavior.
Game theoretical analysis of incentives for large-scale, fully decentralized collaboration networks
2008 IEEE International Symposium on Parallel and Distributed Processing
2008 IEEE International Symposium on Parallel and Distributed Processing
Computer Science