Treat-Before-Trick : Free-Riding Prevention for BitTorrent-Like Peer-to-Peer Networks
Source: North Carolina State University
In P2P file sharing systems, free-riders who use others' resources without sharing their own cause system-wide performance degradation. Existing techniques to counter free-riders are either complex (and thus not widely deployed), or easy to bypass (and therefore not effective). This paper proposes a simple yet highly effective free-rider prevention scheme using (t, n) threshold secret sharing. A peer must upload encrypted file pieces to obtain the sub-keys necessary to decrypt a file which has been downloaded, i.e., sub-keys are swapped for file pieces. No centralized monitoring or control is required. This scheme is called "Treat-Before-Trick" (TBeT). TBeT penalizes free-riding with increased file completion times (time to download file and necessary sub-keys).