Reputation in peer-to-peer networks

At the core of any peer-to-peer network is the primitive of routing, whereby peers assist each other by forwarding transit traffic. However, some nodes may adopt selfish behavior and drop transit traffic due to reasons such as competing commercial interest or conservation of bandwidth. Thus nodes must be able to detect misbehavior as well as use this information to avoid misbehaving nodes. We propose two reputation schemes to address this problem, focusing on the Chord routing protocol. In the first scheme, nodes submit keyspace ranges that they suspect to contain a misbehaving node, and all the ranges are intersected to narrow the keyspace. The second scheme introduces a new routing reputation metric that is allocated to each finger of chord nodes´ routing table. This allows nodes to route to fingers with better reputation in order to have a greater chance of successful delivery. We also present simulation results to evaluate the performances of the two schemes.