Breaking Online Barriers

By Karen A. Frenkel

Technology may provide the tools to overcome Internet censorship. This article appears in the "Defining Internet Freedom ( http://www.america.gov/defining_internet_freedom.html )" issue of eJournal USA ( http://www.america.gov/publications/ejournalusa.html ).

Millions of Internet surfers living in closed societies use free anti-censorship technology to break through online barriers imposed by their authoritarian governments. Several organizations produce that software, including the Censorship Research Center (CRC), the Global Internet Freedom Consortium (GIF), Torproject.org, and the University of Toronto's Citizen Labs (UTCL), which is affiliated with the OpenNet Initiative.

Governments that censor the Internet employ three technical methods. The first blocks visits to specified Internet Protocol addresses. The second filters content, cutting off access to any site with keywords prohibited by the censoring government. The third technique, called Domain Name Redirect, is similar to changing a person's phone number. It makes sites impossible to find.

Software designed to dodge the censor can also work in several different ways. GIF's software tools defeat the blocks, monitors, and traces authorities use to surveil individually owned computers. For example, censor-busting software might scramble the bits and bytes flowing in and out of a Chinese user's computer, so the "Great Firewall of China," as it is known, cannot see patterns in the traffic.

UTCL's software, called Psiphon, is a browser proxy. It enables users behind firewalls to see otherwise-blocked content by delivering Web pages through an intermediate server in an uncensored country. The system works based on trust; someone already with a Psiphon account must invite first-time users. The invitation is an Internet address combined with a code. These enable the newcomer to log in to get credentials and visit an address without anyone knowing they're using Psiphon to get there. The user enters that address into an address bar on any browser and can surf freely from then on.

Torproject.org's Tor software protects users' anonymity by preventing those watching from conducting traffic analysis. It distributes transactions along a random Internet pathway so no single point links a user to his or her destination.

The Censorship Research Center ( http://www.censorshipresearch.org/ ) offers the newest addition to the anti-censorship toolkit. It developed "Haystack" software after an Iranian government crackdown on Internet use after 2009's disputed presidential election. Haystack uses a mathematical formula to hide users' real Internet identity when they visit Web sites. The program lets people in Iran use the Internet "as if there were no Iranian government filters," CRC Executive Director Austin Heap told Business Week.

The opinions expressed in this article do not necessarily reflect the views or policies of the U.S. government.