Tor, a Software for Anonymous Communication
Tor is free software and an open global network that enables anonymous Internet communication. Tor's users use this network of volunteer-operated servers to connect through a series of virtual tunnels rather than make a direct connection so both individuals and organizations can share information over different public networks without compromising their privacy. Besides, Tor allows its users to reach blocked destinations or content and software developers can use Tor as a building block to develop new communication tools with built-in privacy features.
Tor directs Internet traffic through a worldwide volunteer overlay network that consists of more than seven thousand relays. When people use Tor, their traffic gets intermingled with the traffic of other Tor users and as the userbase grows, that route gets more twisted and more hard-to-follow. In this way, Tor protects its users’ privacy against traffic analysis and network surveillance.
Data on the Tor distributed network is encrypted in layers and that’s why the original project’s name was the Onion Router. Tor encrypts the information multiple times and sends it through randomly selected relays. Each relay decrypts only one layer of encryption to discover only the next relay to send the data to and an individual in the circuit never knows the full path.
Tor is open source for Mac, Windows, Linux/Unix, and Android and there are a number of projects and services. Here are some of them:
- Tor Browser requires no installation.
- Arm is a command line application to monitor and configure Tor.
- Metrics portal presents detailed Tor network statistics.
- Tor Messenger is a cross-platform chat program.
- Pluggable Transports helps users bypass censorship against Tor.
- OONI is a global network that monitors censorship, traffic manipulation, and surveillance on the Internet.
- Atlas is a web app that provides an overview of currently running Tor relays.
- Tails is a live USB/CD operating system that is preconfigured to use Tor safely.