Secure and user privacy-preserving searching in peer-to-peer networks

Peer-to-peer (P2P) networks have found growing interest in the research community over the last decade. A P2P network is a distributed system in which peers deploy distributed resources to perform some functions in a decentralized manner. In an unstructured peer-to-peer system, there is no centralized administrative entity, and the contents in the peers are not related to their topological positions in the network. These networks suffer from several problems such as fake content distribution, free riding, whitewashing, poor search scalability, lack of a robust trust model and absence of user privacy protection mechanism. Moreover, the peers can join and leave the network frequently, which makes the designing of trust management frameworks and other protection mechanisms for such networks a complex and difficult task. In this article, a secure and efficient searching protocol for unstructured P2P networks has been proposed that utilizes topology adaptation by constructing an overlay of trusted peers where the neighbours are selected based on their trust ratings and content similarities. While increasing the search efficiency by intelligently exploiting the formation of semantic community structures among the trustworthy peers, the protocol provides a highly reliable module for protecting the privacy of the users and data in the network. Simulation results have demonstrated the effectiveness of the protocol.