JustTorrent: Value Based - Fairer and Faster Protocols for P2P File Sharing

JustTorrent: Value Based - Fairer and Faster Protocols for P2P File Sharing

BitTorrent is a highly effective peer-to-peer file sharing protocol. It allows clients to share large files over the network by dividing a file into pieces and dividing pieces into blocks. Studies so far showed that BitTorrent’s tit-for-tat strategy does not provide fairness. Thus, there were some proposed modifications and extensions. Unfortunately, the previous attempts at providing fairness fail when pieces are not of equal value. In this paper, we consider value-based fairness in BitTorrent, for the first time, as we show that different pieces in a single torrent may be of different value. We suggest two separate modifications to increase fairness and decrease average download time in the BitTorrent protocol. The results of our modifications show us that via fair mechanisms, one may provide security against adversaries who only request valuable pieces in the system. Moreover, one may achieve around 30% better average download times for peers in the system, while remaining fair.

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