—Distributed object search is the primary function of Peer-to-Peer (P2P) file sharing system to locate and transfer the file. The predominant search schemes in unstructured P2P systems have their problems: flooding creates excessive traffic overhead and random walk prolongs search delay. Moreover, both use uniform Time-to-Live (TTL) control for all users, which makes them vulnerable to selfish user attacks, and results in the “free-riding” and “tragedy of the commons” problems. In this paper, we propose a Budget-based Self-optimized Incentive Search (BuSIS) protocol for unstructured P2P file sharing systems, which is robust to and restricts selfish user behaviors. Furthermore, our protocol lowers the search overhead while keeping high hit rate. BuSIS provides differentiated search service for selfish users and ties a user’s contribution to its service level. We present the analytical models on expected search performance, associated search cost and the user satisfac...
Yi Hu, Min Feng, Laxmi N. Bhuyan, Vana Kalogeraki