Exploring the Feasibility of Proactive Reputations

Gayatri Swamynathan, Ben Y. Zhao and Kevin C. Almeroth

Department of Computer Science
University of California
Santa Barbara, CA 93106

Reputation mechanisms help peers in a peer-to-peer (P2P) system
avoid unreliable or malicious peers. In application-level networks,
however, short peer life-times 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.