MARCH: A Distributed Incentive Scheme for Peer-to-Peer Networks

As peer-to-peer networks grow larger and include more diverse users, the lack of incentive to encourage cooperative behavior becomes one of the key problems. This challenge cannot be fully met by traditional incentive schemes, which suffer from various attacks based on false reports. Especially, due to the lack of central authorities in typical P2P systems, it is difficult to detect colluding groups. Members in the same colluding group can cooperate to manipulate their history information, and the damaging power increases dramatically with the group size. In this paper, we propose a new distributed incentive scheme, in which the benefit that a node can obtain from the system is proportional to its contribution to the system, and a colluding group cannot gain advantage by cooperation regardless of its size. Consequently, the damaging power of colluding groups is strictly limited. The proposed scheme includes three major components: a distributed authority infrastructure, a key sharing protocol, and a contract verification protocol.