2010 Circumvention Tool Usage Report, by Hal Roberts, Ethan Zuckerman, Jillian

2010 Circumvention Tool Usage Report (October, 2010), by Hal Roberts, Ethan Zuckerman, Jillian. Berkman Center for Internet and society.

"All circumvention tools use the same basic method to bypass this sort of network filtering: they proxy connections through third party sites that are not filtered themselves. By using this method, a user in China who cannot reach http://falundafa.org directly can instead access a proxy machine like
http://superproxy.com/, which can fetch http://falundafa.org for the user. The network filter only sees a connection to the proxy machine (superproxy.com), and so as long as the proxy itself remains unfiltered, the user can visit sites through the proxy that are otherwise blocked by the network filter. Some, but not all, tools also encrypt traffic between the user and proxy, both so that the traffic between the user and proxy is much more difficult to surveille and so, that filtering triggered by the content of the traffic (instead of merely the destination of the traffic) will not work. Despite this core similarity, circumvention tools differ significantly in many implementation details. We break circumvention tools into four large categories based on their proxy implementations. Each category of tool is distinguished from one another also by virtue of each being closely associated with a single model of financial support. The four categories of tools are:

• blocking-resistant tools
• simple web proxies
• VPN services
• HTTP/SOCKS proxies