Definition
BitTorrent is a file transferring protocol used to distribute large amounts of data. It is peer-to-peer in nature, as users connect to each other directly to send and receive portions of the file. The initial distributor of the complete file or collection acts as the first seed. Each peer who downloads the data also uploads them to other peers. Because of this, BitTorrent is extremely efficient. A minimum of one seed is needed to begin spreading files between thousands of peers.
A BitTorrent client is any program that implements the BitTorrent protocol. Each client is capable of preparing, requesting, and transmitting any type of computer file over a network, using the protocol. A peer is any computer running an instance of a client.
To share a file or group of files, a peer first creates a small file called a "torrent" containing metadata about the files to be shared and about a tracker.
There are central servers called trackers which coordinate the activity of peers. Distributed trackers may be used in combination with Peer exchange and a distributed hash table.
Security
BitTorrent does not offer its users anonymity. It is possible to obtain the IP addresses of all current, and possibly previous, participants in a swarm from the tracker. This may expose users running a BitTorrent client.
There are "cheating" clients like BitThief which claim to be able to download without uploading. Such exploitation negatively affects the cooperative nature of the BitTorrent protocol, although it might prove useful for people in countries where uploading copyrighted material is illegal, but downloading is not.
Popular BitTorrent Portals
- Torrent Portal
- #sztv - Mostly television program content (like YouTube?)
- mininova - Largest BitTorrent portal, based in the Netherlands, does not allow pornographic
- The Pirate Bay - Swedish, good for music, video, and software (shareware, etc).
- isoHunt - works with the RIAA and Microsoft to remove copyright listings.
- torrent spy - shutdown / offline
- SuprNova - Swedish (formerly Slovenian) good for music, video, and software (shareware, etc). Frequently offline. New owners also operate "The Pirate Bay"
- Demonoid - Membership is required to download torrent files older than a few days.