Adaptive P2P Topology Node Model

Authentic Response Rate as Topology Evolves

Effect of Score Manager Redundancy in EigenTrust

EigenTrust Algorithm

EigenTrust Reduces Inauthentic Downloads

Peer-to-Peer Search

2003 - 2005

The fantastic growth of peer-to-peer file-sharing networks in the late 90s and early 2000s highlighted a number of challenges in search in distributed networks of users. Not only is the generation of content distributed among many peers who may have different and conflicting goals, but so too are the algorithms for search.

Since search algorithms in peer-to-peer networks are dependent on the organization and cooperation of peers with diverse aims, the research challenges mirror the challenges in the organization of real-world societies. In particular, robust search in peer-to-peer networks requires social and market mechanisms that reward cooperation, that punish adversarial or free-riding behavior, and that create topologies where peers are connected to those peers with whom they interact productively and disconnected from those with whom they don't.

Our research focuses on designing these mechanisms and encoding them into algorithms and peer-level protocols that facilitate robust information retrieval in distributed networks.

This is joint work with Mario Schlosser, Tyson Condie, Beverly Yang, and Hector Garcia-Molina.

Selected Publications

  • The EigenTrust Algorithm for Reputation Management in P2P Networks. Proceedings of the Twelfth International World Wide Web Conference. (with Mario Schlosser and Hector Garcia-Molina).
  • Simulating a File-Sharing P2P Network. First Workshop on Semantics in P2P and Grid Computing, December 2002. (with Mario Schlosser and Tyson Condie).
  • Incentives for Combatting Freeriding on P2P Networks. Euro-Par 2003, June 2003. (with Mario Schlosser and Hector Garcia-Molina).
  • Adaptive Peer-to-Peer Topologies. Proceedings of the Fourth International Conference on Peer-to-Peer Computing, August, 2004. (with Tyson Condie and Hector Garcia-Molina).
  • Addressing the Non-Cooperation Problem in Competitive P2P Systems. First Workshop on Economics of P2P Systems. (with Beverly Yang and Hector Garcia-Molina).
  • Non-Cooperation in Competitive P2P Networks. The 25th International Conference on Distributed Computing Systems, March 2005. (with Beverly Yang and Hector Garcia-Molina).


  • EigenTrust for Reputation Management in Peer-to-Peer Networks. At WWW 2003.
  • Simulating a File-Sharing P2P Network. At SemPGrid 2003.


  • Query Cycle Simulator Tutorial.