Tor: an anonymizing overlay network for TCP

Tor is a connection-based low-latency anonymous communication system that protects TCP streams: web browsing, instant messaging, irc, ssh, etc.

Remember that this is development code -- don't rely on the current Tor network if you really need strong anonymity.

We've gotten a lot of press lately, and so far the Tor network has stood up just fine to the flood of new users. Great! To help make it scale even better, please consider installing it and then volunteering to run a server. Thanks!

Documentation

Read our How-to for explanations of:

The Design Document (published at Usenix Security 2004) gives our justifications and security analysis for the Tor design:

The Specification aims to give developers enough information to build a compatible version of Tor:

Read the Guide to Tor's source code.

Look at the slides from the Codecon 2004 talk, or listen to the audio from the talk. You can also peruse the Black Hat 2004 slides or Defcon 2004 slides.

Read these papers (especially the ones in boxes) to get up to speed on anonymous communication systems.

Resources

You can get the latest release from the download directory.

Latest experimental: 0.0.9pre2 (sig)
Latest stable: 0.0.8 (sig)
Win32 executable (experimental, contributed): 0.0.8 (sig) Be sure to read the instructions -- you'll need OpenSSL, and don't forget privoxy)

The or-announce mailing list is a low volume list for announcements of new releases, etc. You can read the archives or subscribe.

The or-dev mailing list is for posting by developers only, and the or-talk mailing list is where a lot of the discussion happens. There's also a list for cvs commits.

See the Tor wiki for our FAQ, list of tasks for volunteers, further documentation, etc.

And you can browse the Tor CVS repository: (which may not necessarily work or even compile)

Regularly updated cvs sandbox
ViewCVS
anonymous pserver access (password is guest):
- Make a new empty directory and cd into it.
- cvs -d :pserver:guest@cvs.seul.org:/home/or/cvsroot login
- cvs -d :pserver:guest@cvs.seul.org:/home/or/cvsroot co .
- (use -r tor-0_0_8 or equivalent to fetch a particular version.)

Debian packages have been uploaded to unstable, so you can just apt-get install tor if you are running sid.
For stable (woody) add these lines to your /etc/apt/sources.list file:

deb http://mirror.noreply.org/pub/tor stable main deb-src http://mirror.noreply.org/pub/tor stable main

and then run apt-get update; apt-get install tor. Packages for architectures other than i386 can be added on demand.

If you want a list of current Tor nodes, fetch the latest dynamically generated directory (you're talking http to a tor node!) and look at the "running-routers" line. (Your tor client fetches this automatically, so loading it yourself is just for novelty.) Check out weasel's graph of the number of tor servers over time.