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 © 2007 John Wiley & Sons, Ltd.