Reputation based trust management is increasingly popular in providing a quantitative measurement for peers choosing reliable resources and trusted cooperators in a decentralized Peer-to-Peer (P2P) environment. However, existing approaches do little regarding the validation of a peer's reputation, that is, it is challenging to guarantee the validation and accuracy of computing a reputation value due to malicious denigration or overpraising. In this work, we first investigate the impact of this problem. We then propose TruthRep approach, which encourages peers to provide honest feedback by involving the quality of their evaluations of others into computing reputations. We outline the challenging issues of this design, and present preliminary experimental results.

This paper presents the issue that current reputation systems within peer-to-peer (P2P) networks are based on the fundamental assumption that user feedback (i.e. votes / ratings of other users) are honest and represent the real opinions of peers. However, this is not always the case and user feedback must be validated. The authors have termed this issue as the feedback validation problem. This paper is relevant as it provides a comprehensive review of existing reputation systems. Figure 1 presents a great diagrammatic overview of how a peer's reputation has been defined in existing literature and P2P networks. Future research will look at developing an integrated trust-incentive management protocol based on TruthRep for current P2P applications including BitTorrent, eDonkey and eMule. I will be revisiting this paper in the future as I believe that some aspects of the reputation model and the feedback validation problem is relevant to the development of a sophisticated user contribution measurement models for social software.

• Reputation
• Trust Management
• TruthRep
• Feedback validation problem
• Truthful feedback
• P2PRep, XRep, EigenTrust, Peertrust & Trustguard
• Feedback validation degree