The Electronic Frontier Foundation has published an interesting theory that it is possible to track web browsers based on their web browser’s fingerprint. This fingerprint is of course the data that can be accessed by the server or website the browser connects to.

Math wizards might want to take a closer look at the technical analysis by Peter Eckersley.

There is a mathematical quantity which allows us to measure how close a fact comes to revealing somebody’s identity uniquely. That quantity is called entropy, and it’s often measured in bits. Intuitively you can think of entropy being generalization of the number of different possibilities there are for a random variable: if there are two possibilities, there is 1 bit of entropy; if there are four possibilities, there are 2 bits of entropy, etc. Adding one more bit of entropy doubles the number of possibilitie

The EFF has created a script on a website that computes how unique and trackable a web browser is.

The script will calculate a uniqueness score based on the data that the web browser reveals during connections. Tests with Google Chrome 5, Opera 10.5 pre-alpha, Internet Explorer 8 and Mozilla Firefox 3.6 revealed that all four web browsers contained unique bits that could be used to identify them.

This can be attributed to the web browser fingerprint database of the service as it contains only 450,000 fingerprints. It is likely that an increase here will reduce the uniqueness.

The self-defense aid lists some of the features that one could use to defend against browser fingerprinting:

• Try to use a “non-rare” browser
• Disable JavaScript (please note, Javascript needs to be enabled for the test to work)
• Use TorButton
• A Better Solution: Browsers’ “Private Browsing” Modes

The interesting aspect of this theory is that it is possible to track computers even if cookies have been deactivated in the web browser. There is another option to switching to a non-rare browser though: Browser switching. Identification is only possible for a session in which the same web browser is used. That in combination with disabled JavaScript could prove to be an effective defense against web browser tracking. (found at the Oracle)

That is probably the same line of thought that the developer of Prime Proxies had when he created his website. The website publishes an up to date list of working web proxy servers which are checked regularly so that the chance of encountering a non working proxy server is slim.

Proxies are divided into three categories that are named after the proxy script that is being used on the proxy websites. The three main scripts are PHP Proxy, CGI Proxy and Glyph. Some proxy scripts work better on specific websites than others and it comes down to finding the web proxy server script that displays the favorite websites properly.

The Prime Proxies database contains a list of more than 2300 working and 5000 dead proxy servers. That should be enough for everyone to find a web proxy server that is working and not banned at the location that you are accessing the Internet.

The aim is to provide every Internet user with the opportunity to surf the Internet without fearing censorship or prosecution. The Freedom Stick basically contains a version of TOR and a Firefox browser that can be used to connect to the Internet through The Onion Network.

It was designed with ease of use in mind. Just download the archive from the Chinese Wall page of the German Chaos Computer Club and unpack the contents on the USB device. If autostart is enabled the system should automatically start the Vidalia Control Panel which establishes the connection with the Tor network. Firefox is opened i that connection is successful and the user can surf the Internet using the anonymity of the Tor network.

The stick is only working on Windows operating systems. Linux users on the other hand usually know about these things and are able to implement them easily as well.

Many workarounds exist that help users access those services even if they are currently residing in a different country. One possibility that I would like to explain today is to configure Tor that way that the exit node lies in the country that you want to access the service in. Tor offers lots of so called nodes which are servers in a specific country running the Tor software.

I’m using Vidalia, a package that contains all necessary programs, to explain how a specific country can be selected when using Tor. Download Vidalia and install the software afterwards. The main program interface should load after the installation.

The control panel is displaying the current status of Tor. Additional information are displayed which we are going to use to find servers located in the country that we need an IP address from. A click on View the network displays a visual representation of all Tor servers but only if Tor is running.

Servers can be sorted by country flag and do have a performance indicator next to them as well. Write down some server names with the best performance and leave the menu again. We need to add those servers as exit nodes to the Tor configuration. A click on Settings and there on the advanced tab displays a menu where you find the entry Tor Configuration Menu.

A click on browse opens the browse for files dialog. Left-click on the file “torrc” and choose edit from that menu. Now add the following two lines to the configuration, just paste it at the beginning for instance:

ExitNodes server1, server2, server3
StrictExitNodes 1

Replace server1, server 2 and so on with the server names that you have written down in the network display window. Stop and restart Tor afterwards and the changes should have been made.

Now we have to add a http proxy to our browser. Firefox users click on Tools > Options > Advanced Network and there on the button Settings. Select Manual Proxy Configuration and enter localhost and port 8118 there.

You can test if everything is working fine by visiting my IP lookup script which should display a IP from the country that you have selected the servers from.

OperaTor is not complicated to setup and use. You only need to download the binary executable for Microsoft Windows and unpack it on your system. No installation is required which is great for mobile use. You could for instance copy Operator to your USB stick and run it from any computer that has Internet access. Great for internet cafes and other public computers. Just start the OperaTor.exe and all three required applications will be started automatically. Just use Opera as usual from this point on and rest assured that no data will be saved on the local computer.

It is a good idea to test the connection and make sure that you are really surfing anonymous. The easiest way would be to check that with a script that displays your IP. I have written a basic script that displays your IP. Compare that IP to the one when you are not using OperaTor to know that the service is working.

The developers are updating OperaTor whenever a new version of Tor, Privoxy or Opera come out. Make sure you check the site frequently to always use the latest version of OperaTor.

Update: Operator has been discontinued. The developer has created a new program, called Operator YAPO.