Maryam Babazadeh - School of Electrical and Computer Engineering University of Tehran, Tehran, Iran
Mahmoud Reza Hashemi - School of Electrical and Computer Engineering,University of Tehran, Tehran, Iran

Electronic marketplaces have facilitated access to global markets, reduced transaction costs, enhanced communications and motivated competition. Furthermore, peer-to-peer networks have some characteristics that seems using them in the structure of e-marketplaces can overcome some problems and improve their efficiency. However, using P2P e-marketplaces introduces the new challenge of trust in the establishment of secure and beneficial transactions. In this paper, we present a model for evaluating the trustworthiness of the participants in a P2P based electronic marketplaces. In particular, the aim of this paper is two folds. Firstly we propose a propagation algorithm which is based on statistical techniques and contains trust values, relationship commitments and expertise of the participants in order to evaluate the value of the inferred trust. Secondly we supplement our proposed approach to effectively address opportunistic behavior of the malicious peers within different time windows by the help of a correction factor. Experimental results indicate that in order to interact with trustworthy people, our approach can effectively model the trustworthiness of the participants over time even when they do not have much prior experience with each other.

E-marketplace, Direct Trust, Inferred Trust, Correction Factor