Refraction networking, also known as decoy routing, is a research anti-censorship approach that would allow users to circumvent a censor without using any individual proxy servers.[1] Instead, it implements proxy functionality at the core of partner networks, such as those of Internet service providers, outside the censored country. These networks would discreetly provide censorship circumvention for "any connection that passes through their networks."[2] This prevents censors from selectively blocking proxy servers and makes censorship more expensive, in a strategy similar to collateral freedom.[3][4][5]

The approach was independently invented by teams at the University of Michigan, the University of Illinois, and Raytheon BBN Technologies. There are five existing protocols: Telex,[6] TapDance,[7] Cirripede,[8] Curveball,[9] and Rebound.[10] These teams are now working together to develop and deploy refraction networking with support from the U.S. Department of State.[1][3]

See also


  1. ^ a b "Refraction Networking". Retrieved 2020-12-06.
  2. ^ Frolov, Sergey; Douglas, Fred; Scott, Will; McDonald, Allison; VanderSloot, Benjamin; Hynes, Rod; Kruger, Adam; Kallitsis, Michalis; Robinson, David G.; Schultze, Steve; Borisov, Nikita (2017). "An ISP-Scale Deployment of TapDance". ((cite journal)): Cite journal requires |journal= (help)
  3. ^ a b Braga, Matthew (2017-08-16). "In fight for free speech, researchers test anti-censorship tool built into the internet's core | CBC News". CBC. Retrieved 2020-12-06.
  4. ^ "$1M grant to develop secure, high-capacity research network at U-M". Michigan Engineering. 2020-01-29. Retrieved 2020-12-06.
  5. ^ "'Clever' TapDance approach to web censorship that works at ISP level". Naked Security. 2017-08-25. Retrieved 2020-12-06.
  6. ^ "Telex: Anticensorship in the Network Infrastructure | USENIX". Retrieved 2020-12-06.
  7. ^ Wustrow, Eric; Swanson, Colleen M.; Halderman, J. Alex (2014). TapDance: End-to-Middle Anticensorship without Flow Blocking. pp. 159–174. ISBN 978-1-931971-15-7.
  8. ^ Houmansadr, Amir; Nguyen, Giang T.K.; Caesar, Matthew; Borisov, Nikita (2011-10-17). "Cirripede". Proceedings of the 18th ACM conference on Computer and communications security. CCS '11. Chicago, Illinois, USA: Association for Computing Machinery. pp. 187–200. doi:10.1145/2046707.2046730. ISBN 978-1-4503-0948-6. S2CID 11019789.
  9. ^ "Decoy Routing: Toward Unblockable Internet Communication | USENIX". Retrieved 2020-12-06.
  10. ^ Ellard, D.; Jones, C.; Manfredi, V.; Strayer, W. T.; Thapa, B.; Welie, M. Van; Jackson, A. (2015). "Rebound: Decoy routing on asymmetric routes via error messages". 2015 IEEE 40th Conference on Local Computer Networks (LCN). pp. 91–99. doi:10.1109/LCN.2015.7366287. ISBN 978-1-4673-6770-7. S2CID 12887876.