Exploring the Feasibility of Proactive Reputations

Reputation mechanisms help peers in a peer-to-peer system avoid unreliable or malicious peers. In application-level networks, however, short peer lifetimes mean reputations are often generated from a small number of past transactions. These reputation values are less ‘reliable’, and more vulnerable to bad-mouthing or collusion attacks. We address this issue by introducing proactive reputations, a first-hand history of transactions initiated to augment incomplete or short-term reputation values. We present several mechanisms to generate proactive reputations, along with a statistical similarity metric to measure their effectiveness. Copyright c © 2007 John Wiley & Sons, Ltd.