Treat-before-trick : Free-riding prevention for BitTorrent-like peer-to-peer networks

In P2P file sharing systems, free-riders who use others’ resources without sharing their own cause system-wide performance degradation. Existing techniques to counter freeriders 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 subkeys necessary to decrypt a file which has been downloaded, i.e., subkeys are swapped for file pieces. No centralized monitoring or control is required. This scheme is called “treat-beforetrick” (TBeT). TBeT penalizes free-riding with increased file completion times (time to download file and necessary subkeys). TBeT counters known free-riding strategies, incentivizes peers to donate more upload bandwidth, and increases the overall system capacity for compliant peers. TBeT has been implemented as an extension to BitTorrent, and...

• Type: Conference
• Year: 2009
• Where: IPPS
• Authors: Kyuyong Shin, Douglas S. Reeves, Injong Rhee
• Keywords: Distributed And Parallel Computing, IPPS 2009, System-wide Performance Degradation, Threshold Secret Sharing, file Pieces