Exploiting BitTorrent For Fun

This paper assesses BitTorrent’s robustness against selfish peers, who try to download more than their fair share by abusing existing protocol mechanisms. We design and implement three selfish-peer exploits and evaluate their effectiveness on public and private torrents. In practice, BitTorrent appears quite robust against this kind of exploit: selfish peers can sometimes obtain more bandwidth, and honest peers’ download rates suffer slightly in consequence, but we observe no considerable degradation of the system’s quality of service. We identify private-torrent scenarios in which a selfish peer could benefit more significantly at the expense of honest peers, and discuss the BitTorrent protocol mechanisms that lead to robustness by rendering these scenarios infeasible.