Fighting Freeloaders in Decentralized P2P File Sharing Systems

Date of Submission: 
January 14, 2004
Report Number: 
04-004
Report PDF: 
Abstract: 
Currently used P2P file-sharing systems such as Gnutella suffer from a freeloading problem due to absence of enforcible decentralized mechanism to motivate peers to provide services to others. Freeloading leads to a defacto centralized system that is susceptible to DoS attacks and provides poor service to its participants. In this paper, we propose a decentralized mechanism that avoids on-line polling and forces peers to contribute their bandwidth to the system. We discuss additional positive properties of the model and, finally, discuss how to deal with collusion and Sybil attacks.