Computer science works on challenges of Internet routing and censorship.

by Karen Wentworth

The Internet we use daily was built by millions of people reacting and adapting to each other on a seemingly endless number of networks, servers, routers, and other back-end systems. As a consequence, no one can precisely know how electronic data will move as it travels, and if the data will move without incident. The UNM Computer Science Department works on a variety of projects that explore the way data is routed, re-routed, and censored.

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Policing the Flow of Traffic

UNM graduate student Josh Karlin is intrigued with the way Internet traffic moves and what happens when it is routed in unexpected ways.  He says that usually, Internet data reaches its intended destination, but occasionally someone may redirect traffic (intentionally or accidentally), causing service disruptions for Internet service providers (ISPs) and users.

Karlin and his advisor, Professor of Computer Science Stephanie Forrest, developed a watchdog for Internet routing disruptions with the help of a National Science Foundation grant.  The watchdog is software that automatically warns ISP, when their traffic is routed to another destination. It is a free service called the Internet Alert Registry, or IAR, and can be found at http://iar.cs.unm.edu

When suspicious activity occurs, the IAR sends an alert to the affected ISPs. They can look at the alert and react if it appears that their traffic is improperly routed. Karlin and Forrest are now taking the next step by building software that will automatically delay the adoption of suspicious routes so that ISPs can respond to them before they propagate.

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China Eyes on the Internet

How does a country or a company censor the information people receive over their Internet connections? 

That is the question UNM Assistant Professor Jedidiah Crandall and his students are investigating. They had an unusual opportunity to explore the question this summer as they tried to move keywords through Internet routes into China before and during the 2008 Summer Olympics.

When journalists arrived in Beijing before the Olympics, they immediately began to protest the censorship of some Internet addresses and Chinese authorities removed those blocks, but Crandall says they left in place more subtle forms of censorship. He says two major goals of the censors is to prevent access to sensitive topics and to stop protests from forming, so his group tried word combinations like “hunger strike,” “petition,” “dissident,” “persecution,” and “suppression.”

What they found was far more complex than simple blocking of banned words. The results of the probing suggested that the government reduced censorship, but not for all keywords in all places. Some keywords remained blocked in some places. Websites that use a blacklisted key word are blocked, but the blockage isn’t perfect because of the way Internet data travels through a variety of routes in and out of the country.

Certain words traveling one router might be blocked, but the same words traveling through different routers might go through, especially during times of heavy Internet traffic. Crandall believes that would explain why reporters in some Beijing hotels were unable to access some Web sites, while other reporters in the same hotel were able to reach those same sites. 

Crandall says the Chinese authorities make good use of reports that certain words or Web sites are banned to encourage Internet users to self-censor by avoiding those sites or phrases, capitalizing on the ambiguity of what is or isn’t acceptable communication.

His research group is now examining free anti-censorship tools that are available. Crandall says they are finding that at least some of the tools are falsely detected as malicious Trojan horses, worms, or backdoors for some anti-virus products. This finding makes it much more problematic for people trying to navigate the complex problems of Internet censorship.

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