The first public release occurred a year later. The alpha version of Tor, developed by Syverson and computer scientists Roger Dingledine and Nick Mathewson and then called The Onion Routing project (which was later given the acronym 'Tor'), was launched on 20 September 2002.

Onion routing is implemented by means of encryption in the application layer of the communication protocol stack, nested like the layers of an onion.

Reed and David Goldschlag, to protect American intelligence communications online. The core principle of Tor, onion routing, was developed in the mid-1990s by United States Naval Research Laboratory employees, mathematician Paul Syverson, and computer scientists Michael G. It protects user's freedom and ability to communicate confidentially through IP address anonymity using Tor exit nodes. Tor protects personal privacy, concealing a user's location and usage from anyone performing network surveillance or traffic analysis. Using Tor makes it more difficult to trace a user's Internet activity. It directs Internet traffic through a free, worldwide, volunteer overlay network consisting of more than seven thousand relays. Tor, short for The Onion Router, is free and open-source software for enabling anonymous communication. Comparison of Internet Relay Chat clients.Overlay network, mix network, onion router, Anonymity application Unix-like, ( Android, Linux, BSD, macOS), Microsoft Windows, iOS

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