Posted by oussama at 5:49 AM
State-backed internet censorship is the method of choice for countries that want to crack down on citizens spreading messages of revolution online. But now dissidents have a tool to help them fight back.
Telex, developed by computer scientists at the University of Michigan, US and the University of Waterloo, Canada, transmits information to blocked websites by piggybacking on uncensored connections with the aid of friendly foreign internet service providers (ISPs).
Dissidents install the Telex client, perhaps from a USB stick smuggled over the border. They then make a secure connection to an uncensored site outside of the censor's network - nearly any site that uses password logins will do. The connection looks normal, but Telex tags the traffic with a secret key.
Foreign ISPs in the network between the client and destination site can look for these tags and redirect the connection to an anonymising service such as a proxy server, which allows users to connect from one location while appearing to be elsewhere. Using Telex is more robust than using such servers directly, as censors can easily block access to a proxy once it is discovered.
The researchers have tested the system by watching YouTube videos in Beijing, China, despite the site being blocked in that country, but they say it's not yet ready for real users. One barrier might be the need for foreign ISPs to install Telex software. "Widespread ISP deployment might require incentives from governments," suggest the researchers - something that the US government might be interested in given its plans to provide rebels with an "internet in a suitcase". Telex also wouldn't be able to help during an Egypt-style disconnect, as dissidents must at least be able to connect to uncensored sites.