Ten tools--some commercial products and some open-source, nonprofit efforts--were tested for the new study, which was conducted partly in a lab setting at Harvard and partly in cybercafes in Beijing, Shanghai, Hanoi, and Seoul. Hal Roberts, a senior researcher at Berkman, visited the cafes and ran the circumvention tools through their paces. The best tools overall were found to be Ultrareach, Psiphon, and Tor, while Dynaweb and Anonymizer also scored well. Others suffered greater problems with usability or security.

"All of the tools we tested worked in the sense that if you sat in an Internet cafe in China and tried to bring up a site, you could do it," says Roberts. But a major problem, he says, was the long loading times of restricted pages, a function of limited bandwidth at proxies or the additional hops the data took to reach the cafe. "The only tool that was even marginally unpainful was Ultrareach," Roberts says, "but even for Ultrareach, it was anywhere from two to eight times slower than direct connection." In some cases, the extra time helps provide added security--notably for Tor.

The larger issue is that circumvention tools are only used by a few million people around the world--a small number, considering that China alone has some 300 million Internet users. The challenge ahead will include spreading the word more widely, increasing the availability of proxy computers, and enlisting more technical and financial support in the fight against censorship.

Circumvention research is supported by human-rights and civil-rights organizations, including Human Rights Watch and the Electronic Frontier Foundation, and by some Western governments. "It's easy to understand why governments and human rights funders would be interested in supporting censorship circumvention tools," notes the text of the report, which was coauthored by Palfrey, Roberts, and Ethan Zuckerman, who heads a blogging advocacy group called Global Voices. "As discourse shifts from traditional media to new participatory media, the ability to access and create online information becomes equivalent to the ability to read, listen, and speak freely."