The Tor Network: Anonymity Online

“The idea of forcefully having people live with a religious symbol they do not believe in is sheer stupidity. Crosses should go. The government is acting stupidly on the issue.”

I can make such a statement because I live in a democracy. Not everyone has this luxury. In some countries, such a statement directed at the ruling president of the country can land me in jail if I am lucky, on the missing person’s list if I’m not.

The internet is brimming with content and anyone with an internet connection can, in a matter of minutes, get information on any topic. Newsgroups, chat programs, forums and social networks allow people to interact with others to discuss issues, publicize causes and voice opinions. The internet, if unchecked, constitutes one of the biggest problems to regimes that limit their citizen’s freedom of speech. Many-a-times, freedom of speech goes hand in hand with freedom of information. Therefore a dictator will block all avenues that consider opinions different from his own.

The internet is based upon the simple concept that each and every connected computer has a number that uniquely identifies it. This is known as the IP address. When you request a particular web page, your IP address and that of the server hosting the web page come into play. Each communication on the internet normally consists of three parts: the IP address of the computer you want information from (destination), your IP address (source) and the type of operation you require (for example view a particular web page or post a message to a forum). A dictator can easily implement systems that analyze this information. From observed communications he can easily build up a profile of what each citizen is doing and which servers he spends time on.

When it was first launched, the Tor Network was called the Onion route. Its name originated from the fact that to get from the outside to the inside of the onion one must work through a series of intermediate layers. It was originally developed by the US Navy. In 2004, the second-generation onion route was launched under the name of Tor Network. The Tor Network consists of a distributed network of volunteer relays from all around the world. It prevents somebody watching your Internet connection from learning what sites you visit and what operations you are performing on these sites. When you request a page via Tor, rather than going directly to the page you desire, your request is directed to a computer forming part of the Tor network. This in turn hands over your request to another member computer which in turn passes it on to a third. The third computer finally contacts the server you originally wanted information from. The response from the server is routed via the same route. Anyone eavesdropping your internet connection will only be able to determine the IP address of the first computer in the Tor network chain and the IP address of the computer you are actually interested in will never be revealed.

Last February, ABC News announced that the Iranian authorities had blocked Web sites promoting the presidential bid of Mohammed Khatami. Iran is one of the countries that has repeatedly blocked political, religious and other web sites the government feel go against the “best interest of its citizens”. When a citizen requests an IP address of a web site that is on the government’s black list, the communication will be terminated. Think of this as government imposed parental control.

Since in the Tor system the citizen never deals with the prohibited site directly, such restrictions never come into force. The only transmissions the government observes are between the citizen’s computer and one of many computers forming part of the Tor network. Since these would not be blacklisted communication will take place.

In mainland China the internet is controlled. Official sources claim that this is done for the good of the people. The thirty thousand strong Chinese internet police actively monitor instant messaging, chat rooms, and emails for traffic related to the organization and publicizing of protests that go against the party doctrines. Pollution, corruption and the discussion of matters related to Tiananmen Square and Tibet are some of the monitored content. Reports of Chinese citizens being prosecuted by the state over comments and publications they placed on the internet have periodically made it to the world press.

Under normal circumstances, information transmitted through the internet is not encrypted. Therefore internet police may read the type of operation being requested. Suppose a citizen sends a message complaining about corruption in a Chinese province. If that message can be read, it would be sufficient to get him into trouble. Communication between the citizen’s computer and each computer forming part of the Tor network is encrypted. By encrypting the data as it is transmitted between the citizen’s computer and all computers forming part of the Tor network, this type of invasion of privacy cannot take place. If the destination site only works with unencrypted data, the last computer forming part of the communication chain decrypts the data before sending it to the destination computer. Any response from the destination computer is encrypted once it reaches the first computer in the Tor network and is transmitted all the way to the citizen in undecipherable form.

A police informant, a journalist operating in a sensitive zone or a person close to Burma’s Aung San Suu Kyi may have his or her internet communication analyzed. In this scenario, the IP addresses of the servers the citizen connects to are analyzed in order to draw a picture of what sites are frequented. Regimes may try to infiltrate the Tor network to understand what monitored individuals are doing.

By constantly changing the computer to which one connects to, this form of analyses is circumvented. It is possible for each session to take a different route from the one before it because of the thousands of volunteers who make up the Tor network. Each computer on the Tor network forming part of the communication chain never knows more information beyond that which is necessary to maintain the transmission of data. This ensures that if a government tries to infiltrate the Tor network with its own computers, it will never be able to figure out the source, destination and content of a message all at the same time.

To become part of the Tor network go to www.torproject.org. Your involvement with Tor may one day allow a whistle blower to communicate with authorities an imminent terror plot or you may help transmit a short mobile phone video of a riot in Iran.