Have you ever wondered how to browse the web truly anonymously? Believe it or not, it is possible. Here's how.

For those eager to get started, the process goes like this:
1) install Firefox
2) install the Stealther extension
3) install Tor & Privoxy
4) install the TorButton extension
5) install the User Agent Switcher extension

When browsing the web you have to either cover your tracks, erase your tracks, or obfuscate your tracks in two places: your local machine & websites that you visit. Your browser stores a history of sites that you visit, along with cookies and a local cache of images and other content from those sites. Every website that you visit stors a copy of the IP address of every computer that visits that website. User statistics can also be collected, your web browser & operating system for example.

Because your machine is under your control, hiding your tracks here is relatively easy. Installing the Stealther extension comes with the option of enabled or disabled. When enabled the extension will block all cookies, disable your history, disable your local cache, and disable ReferrerHeader (this lets other websites know which site you were visiting immediately before visiting their site). A fun test to run with Stealther is to log into a website like Gmail, turn on Stealther, and then return back to the Gmail homepage where you will notice that it thinks you are no longer signed in. Nice!

Now it gets complicated
Almost everyone knows that computers on the internet each have a unique number identifying that machine's location called an IP address. IP address spoofing is very technical in nature, often violates the terms of your ISP, and still doesn't hide the actual path of your outgoing packets. One other option you have is to route your data from one machine, to another machine, to another machine, to another machine, etc. so that the chain becomes so long that it is very time consuming to track down the originator. You would of course want to ensure that your data is encrypted and not viewable by other machines in this long chain and that the chain works quickly enough to browse the web.

This all sounds very complex doesn't it? Well it is, but thankfully there are enough people out there concerned with this sort of thing that they have written some open source software just for this purpose. It comes in two pieces: Tor (the traffic router) and Privoxy (a proxy that lets your browser connect to the Tor network). You can get both pieces from our friends at the EFF: tor.eff.org. Follow their instructions to configure Tor and Privoxy on your machine.

I feel it is important to mention that Tor is a world-wide effort. Remember those people in China that have their internet filtered? Tor works for them too. And because Tor is worldwide your data may be sent to Canada, then to Ireland, then to Egypt, then to Russia, etc. This means that for authorities in your home country to track you down they would have to have to follow the laws in each country to obtain this information to use in court. The amount of time, money, and politics inovolved in this process is almost entirely prohibitive.

So does all this data hopping slow down your browsing experience? Yes, definitely. I would only recommend using Tor when you need to do something that demands privacy. For day-to-day browsing this is not your solution.

After you have Tor installed (and the TorButton extension to make it easy) a fun test to run is to visit IPChicken.com both with Tor on and Tor off. You will notice that IPChicken suddenly thinks that you have a different IP address, are coming from another university, often another country. Nice!

The UserAgent
But what about that other data listed at IPChicken? Notice that the site can still determine your browser and operating system? This is also data that could be used to trace you. This information can be falsified using the User Agent Switcher extension. This lets Firefox trick websites into thinking that it is Safari in OS X or Netscape in Windows 98, for example. Neat stuff eh?

Lastly, if you want to remain truly anonymous:
1) use a free wireless network
2) use an external USB wireless network card

Why? The first is obvious, if you are on a free wireless network it can never be traced to your home. But second, every network card has a unique number that identifies it from all other network cards. This is called the MAC address. If you are using a laptop the MAC address pretty much makes your computer unique and indentifiable from all other computers in the world. If you use an external USB wireless network card the MAC is different from the one built into your latop and at least the purchase is much harder to trace. As a last ditch effort the card is disposable if you are really that paranoid.

Why
To quote the EFF, "Ongoing trends in law, policy, and technology threaten anonymity as never before, undermining our ability to speak and read freely online. These trends also undermine national security and critical infrastructure by making communication among individuals, organizations, corporations, and governments more vulnerable to analysis." Regardless, this information is empowering. I hope it empowers you to do what you believe is right.