PeerTrust: A Trust Mechanism for an Open Peer-to-Peer Information System

Abstract

In an open peer-to-peer information system, peers often have to interact with unknown or unfamiliar peers and need to manage the risk that is involved with the interactions without any presence of trusted third parties or trust authorities. It is important for peers to be able to reason about trust when interacting with each other to accomplish a task. This paper presents PeerTrust, a simple and yet effective trust mechanism for quantifying and comparing the trustworthiness of peers. We argue that the amount of satisfaction a peer obtains through interactions, the total number of interactions that a peer has with other peers, and the balancing factor of trust all play a crucial role in evaluating the trustworthiness of the peer. This paper also discusses the architecture and the design considerations in implementing this mechanism in a decentralized peer-to-peer system. We report the set of initial experiments, showing the feasibility, the cost, and the benefit of our approach.