Internet freedom in the network’s core
Most of today’s censorship circumvention tools use the same fundamental approach: they encrypt the user’s traffic to make it look innocuous, and channel it to a proxy server located outside the censored network. This leads to a fundamental problem: Once the censor discovers the proxy server, the proxy itself becomes just another site to block. If users can find the proxy servers, the censors can too.
In this race to find and use—or find and block—proxy servers, censoring governments enjoy natural, growing advantages over censored users. For example, they can examine all data flowing across their borders in search of disfavored activity. Strategies that rely on friendly servers are failing against increasingly sophisticated state-level censors who can see and control a country’s entire network.
Refraction networking was independently invented in 2011 by three engineering teams. Five protocols exist: Telex and TapDance at the University of Michigan, Cirripede at the University of Illinois, and Curveball and Rebound at Raytheon BBN Technologies. These designs share the same basic premise but represent a range of design choices and technical tradeoffs.
Today, researchers from Michigan, Illinois, BBN, and the University of Colorado have formed a coalition to make refraction networking a widely deployed and powerful tool for Internet freedom, with support from the U.S. State Department's Bureau of Democracy, Human Rights, and Labor. In early 2017, the coalition ran a real-world ISP trial—the first of its kind—providing refraction to more than 50,000 users.
The papers are:
Beyond the work of our coalition, several other research papers directly address issues connected with refraction networking:
The refraction networking coalition is working to partner with network operators. If you’d like to find out more or help support our efforts, please contact us at email@example.com.