TL; DR: Using a global network of volunteer-operated servers, Tor helps Internet users improve their online privacy and security. Tor programs direct Internet traffic through several relays and encryption layers to conceal someone’s location and protect them from network surveillance and traffic analysis. Used for a wide range of reasons, Tor helps users avoid censorship and access the complete Internet with programs including a web browser, mobile app, chat app, and more. Supporters can help Tor in many ways: running a relay, donating, volunteering, and contributing development time to projects.
Originally developed for protecting government communications, the Tor network now also shields Internet users from surveillance and provides a way around government-censored web access.
The network of thousands of volunteer-run servers boosts online privacy and security, providing anonymous paths for Internet users to deliver and search for unlimited information.
The original project, run by computer scientists and mathematicians at the US Naval Research Laboratory in the early 2000s, provided the flavorsome inspiration for the network’s name and logo — Tor is short for The Onion Router.
Who Needs Online Anonymity and Why Millions of People Choose Tor
Given the privacy and security protections offered by Tor, people around the world access the network for a variety of reasons:
- Journalists communicate sensitive information with sources as well as research and publish articles that oppose state-controlled media.
- Law enforcement officers and militaries provide truly anonymous tip lines, engage in undercover operations, and gather intelligence.
- Activists and whistleblowers report abuses from danger zones, organize protests, avoid surveillance, and circumvent government censorship.
- Businesses avoid misleading information from competitors, keep operational strategies confidential, and facilitate internal accountability.
- IT professionals verify IP-based firewall rules, conduct testing, bypass security settings for nontechnical employees, and work around ISP network outages.
Beyond the specialized industries above, general Internet users can use Tor to protect their identity from thieves and advertisers, guard private data from irresponsible companies, safeguard children’s online activities, research sensitive topics, as well as avoid surveillance and censorship.
How Tor Works: Peeling Back the Layers of Onion Routing
Paul Syverson, Roger Dingledine, and Nick Mathewson launched the alpha version of Tor in 2002, with a public release happening a year later. The Naval Research Laboratory released the code for Tor under a free license, and the Electronic Frontier Foundation began funding the project.
As the original name implies, Tor relies on onion routing, which nests layers of encryption across a wide network. Internet traffic, or data packets, have two parts: the payload, or information being sent, and the header, which displays source and destination locations, file sizes and types, along with other identifying information. Internet service providers and other surveillance programs can examine headers for revealing data.
The Tor network obscures header information by routing traffic through several detours across the Internet. Instead of going directly from the source to the destination, data on the Tor network take random paths through a handful of more than 7,000 available relays.
Each relay connection is encrypted a step at a time, meaning no relay ever knows the data packet’s full path. A user’s path through the Tor network changes every 10 minutes.
Our 4 Favorite Tor Programs Help Users Browse and Share Info Online
The non-profit Tor Project and an open community of developers maintain 14 software programs and services to secure users’ Internet experiences, ranging from mass-market products, like a web browser and chat client, to more technical software like a terminal status monitor and discrete-event network simulator.
1. Tor Browser: Portable, Pre-Configured Web Browser
The bullet-proof way to access the Tor network is through their browser and bundled programs. Based on an Extended Support Release (ESR) branch of Firefox, Tor Browser adjusts browser preferences and applies a series of patches to improve privacy and security.
Torbutton and Tor Launcher extensions further obscure a user’s online activity, while HTTPS-Everywhere, NoScript, and other plugins protect their privacy. Tor warns that almost any other web browser configuration will likely be unsafe to use with Tor.
2. Tor Messenger: Secure, Cross-Platform Chat Program
Also based on something from the Mozilla community, Tor Messenger uses Instantbird to create a secure chat platform that supports a wide variety of communications, including XMPP, IRC, Twitter, Facebook, and others.
Tor Messenger is still in beta but sends all traffic through the Tor network with an excellent user interface, secure updater, along with automatically enabled Off-the-Record messaging. Future releases, which are expected to be paired with Mozilla’s ESR cycle, could include multi-party communication features, encrypted file transfers, and international versions.
3. Orbot: Private Internet Connections for Android Devices
Android users can access the web, instant messaging, and email through the Tor network by using Orbot, a free app created as part of a partnership with the Guardian Project. Orbot includes Tor and the libevent API, along with a local HTTP proxy and SOCKS4A/5 interface.
Orbot can be used for any app with a proxy feature and can be configured to transparently proxy all of the device’s Internet traffic through Tor.
4. Tails: Movable, Private Linux Distribution
Nicknamed the amnesic incognito live system, Tails is an operating system that boots from a USB drive, DVD, or SD card. Because it is confined to removable media, Tails leaves no evidence of its usage on whatever computer on which it runs.
Tails comes with several built-in applications, including a web browser, instant messaging program, email client, image and audio editor, and a productivity suite, all pre-configured for Tor security and privacy.
How You Can Contribute and Get Involved With the Tor Project
The Tor Project relies on volunteers to support and develop software, along with maintaining and growing the network.
Currently supported by X, Y, and Z, Tor also seeks donations and sponsorships from businesses, organizations, or governmental agencies.
Volunteers with at least 2Mbps for upload and download can configure their Tor to donate bandwidth and become a network relay — the more relays, the faster the Tor network. Tor users can also test complementary programs, contribute documentation, and translate documentation — particularly into Arabic or Farsi — for users living in censored-Internet areas.