  The existing peer-to-peer networks have several problems such as fake content
distribution, free riding, white-washing and poor search scalability, lack of a
robust trust model and absence of user privacy protection mechanism. Although,
several trust management and semantic community-based mechanisms for combating
free riding and distribution of malicious contents have been proposed by some
researchers, most of these schemes lack scalability due to their high
computational, communication and storage overhead. This paper presents a robust
trust management scheme for P2P networks that utilizes topology adaptation by
constructing an overlay of trusted peers where the neighbors are selected based
on their trust ratings and content similarities. While increasing the search
efficiency by intelligently exploiting the formation of semantic community
structures by topology adaptation among the trustworthy peers, the scheme
provides the users a very high level of privacy protection of their usage and
consumption patterns of network resources. Simulation results demonstrate that
the proposed scheme provides efficient searching to good peers while penalizing
the malicious peers by increasing their search times as the network topology
stabilizes.
