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Center for Education and Research in Information Assurance and Security

Refraction Networking: Censorship Circumvention in the Core of the Internet

Nikita Borisov - University of Illinois at Urbana-Champaign

Nov 08, 2017

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Internet users around the world are facing censorship. To access blocked websites, they use circumvention services that most commonly consist VPN-like proxies. The censors, in turn, try to block such proxies, creating a sort of cat-and-mouse game. Refraction networking takes a different approach by placing refracting routers inside ISP networks. By spending a special signal, a user can ask a router to refract *any* connection that transits the ISP to another, blocked destination, in a process that is undetectable by the censor. To prevent such connections, the censor would need to block all traffic from reaching that ISP, which considerably raises the cost of censorship.

I will discuss the design of refraction networking and how it achieves the properties above. I will also discuss the results of our a pilot deployment of refraction networking two ISPs handling an aggregate of nearly 100 Mbps traffic, which provided censorship circumvention to 50,000 users in a country with heavy Internet censorship. I will close by discussing some future research issues in the space.

About the Speaker

Nikita Borisov is an associate professor at the University of Illinois at
Urbana-Champaign. His research is interests are online privacy and network
security, with recent work on anonymous communication, censorship resistance,
analysis of encrypted traffic, and protocols for secure communication. He is
the co-designer of the Off-the-Record (OTR) instant messaging protocol and was
responsible for the first public analysis of 802.11 security. He has been the
chair of the Privacy Enhancing Technologies Symposium and the ACM Workshop on
Privacy in Electronic Society. He is also the recipient of the NSF CAREER
award. Prof. Borisov received his Ph.D. from the University of California,
Berkeley in 2005 and a B.Math from the University of Waterloo in 1998.

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