Trackerless torrents

The BitTorrent file sharing system is in the news this week for a couple of reasons. The first of those is that BitTorrent has announced a beta with "Trackerless" publishing, which allows users to share files without maintaining a centralized tracker. The protocol is also in the news, predictably, due to the release of "Star Wars III: Revenge of the Sith." The Motion Picture Association of America (MPAA) has used the publicity around the movie to launch another attack on BitTorrent. Predictably, "Sith" did end up being available via BitTorrent, and 20th Century FOX is already issuing takedown notices to ISPs.

The trackerless technology is also getting attention as a tool to share illegal content, with no mention of the legitimate uses of BitTorrent. Given the coverage of "trackerless" BitTorrents so far, some might think that offering a "trackerless" BitTorrent would prevent detection by companies like BayTSP. However, "trackerless" is a far cry from anonymous. While a tracker site presents an obvious target for entertainment industry lawyers, there's nothing about so-called trackerless publishing that prevents detection.

As one might have surmised already, trackerless is actually a misnomer. In fact, as the BitTorrent press release acknowledges, it's actually a "lightweight tracker." To share a "trackerless" file, a user generates a .torrent file in much the same way that one would generate a normal .torrent tracker. This file still need to be published via a website and public Internet connection. As the BitTorrent page says, "Anyone with a website and an Internet connection can host a BitTorrent download!" Individuals who share files using trackerless BitTorrent may have a better chance of flying under the radar, and once a file has been shared by the original owner there's no need for that user to maintain their tracker, but it's not anonymity.

BitTorrent isn't the first to offer trackerless support. The Azureus project, for example, also offers an "embedded tracker" that allows users to share torrents directly. However, the two technologies seem to be incompatible at the moment.

The trackerless system is more convenient for users who are looking to share content legally. Once a user has seeded the network with a file, there's no need for that user to continue hosting their tracker, though this also makes the trackerless system less reliable than having a centralized tracker.

It should also be noted that users should think twice before sharing movies, music or other content illegally. The entertainment industry has traditionally gone after uploaders only, but BitTorrent users who share files are uploaders as well as downloaders.

While LWN would not encourage sharing copyrighted material illegally, there are alternatives for users who want to remain anonymous for other reasons. For example, the Electronic Frontier Foundation has sponsored development of an anonymous system called Tor, which can be used for browsing, publishing, SSH and BitTorrent. We'll be looking at Tor on this page within the next couple of weeks.

---

(Log in to post comments)