DATE: Thursday , April 25, 2002
TIME: Noon - 1 pm
PLACE: Wean Hall 8220

Nick Feamster

Infranet: Circumventing Web Censorship and Surveillance
Contributing: Nick Feamster, Magdalena Balazinska, Greg Harfst, Hari Balakrishnan, David Karger

An increasing number of countries and companies routinely block or monitor access to parts of the Internet. To counteract these measures, we propose Infranet, a system that enables clients to surreptitiously retrieve sensitive content via cooperating Web servers distributed across the global Internet. These Infranet servers provide clients access to censored sites while continuing to host normal uncensored content. Infranet uses a tunnel protocol that provides a covert communication channel between its clients and servers, modulated over standard HTTP transactions that resemble innocuous Web browsing. In the upstream direction, Infranet clients send covert messages to Infranet servers by associating additional semantics to the HTTP requests being made. In the downstream direction, Infranet servers return content by hiding censored data in uncensored images using steganographic techniques. Our security analysis shows that Infranet can successfully circumvent several sophisticated censoring techniques. We describe the design, a prototype implementation, and measured performance of Infranet, highlighting the tradeoffs between the level of security achieved and the performance of Infranet browsing.

Nick Feamster is a graduate student in the Networks and Mobile Systems group at the Laboratory for Computer Science at MIT under the supervision of Professor Hari Balakrishnan. His research focuses on security, network video, and wide-area networking. Nick has interned at HP Labs, Bell Labs, and AT&T Labs. He is an NSF Graduate Research Fellow and the recipient of the Best Student Paper award at USENIX Security 2001.

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