Tor (Network)
Tor is a free anonymity network that routes internet traffic through a series of volunteer-run servers, hiding users' locations and activity from network surveillance. Traffic "is relayed and encrypted three times as it passes over the Tor network", across "thousands of volunteer-run servers known as Tor relays".[1] Its name comes from "The Onion Router", after the layered encryption it uses.
History
Onion routing was developed in the mid-1990s at the US Naval Research Laboratory by Paul Syverson, Michael Reed and David Goldschlag. Building on their work, Roger Dingledine and Nick Mathewson developed Tor, which was deployed in October 2002. The Tor Project, a nonprofit, was founded in 2006 to maintain it, and development of the Tor Browser began in 2008.[2] Dingledine, Mathewson and Syverson described the design in "Tor: The Second-Generation Onion Router", presented at the USENIX Security Symposium in 2004.[3]
How it works
A Tor connection passes through three relays. Each layer of encryption is removed by one relay, so no single relay knows both where the traffic came from and where it is going. Tor also supports onion services, websites reachable only through the network, whose own locations are hidden.
Use and surveillance
Tor is used by journalists, activists and ordinary users seeking privacy, as well as for illicit activity. Documents leaked by Edward Snowden in 2013 showed that the US National Security Agency had struggled to break it; one slide stated: "We will never be able to de-anonymize all Tor users all the time."[4] In late 2026, Tor's metrics counted roughly three million users connecting each day.[5]
See also
References
- ↑ "The Tor Project". Retrieved November 12, 2026.
- ↑ "History". The Tor Project. Retrieved November 12, 2026.
- ↑ 2004. "Tor: The Second-Generation Onion Router". USENIX. Retrieved November 12, 2026.
- ↑ James Ball, Bruce Schneier and Glenn Greenwald (October 4, 2013). "NSA and GCHQ target Tor network that protects anonymity of web users". The Guardian (republished by Schneier on Security). Retrieved November 12, 2026.
- ↑ "Directly connecting users". Tor Metrics. Retrieved November 12, 2026.