Background

The Dissent project is a research collaboration between Yale University and UT Austin to create a powerful, practical anonymous group communication system offering strong, provable security guarantees with reasonable efficiency. Dissent's technical approach differs in two fundamental ways from the traditional relay-based approaches used by systems such as Tor:

  • Dissent builds on dining cryptographers and verifiable shuffle algorithms to offer provable anonymity guarantees, even in the face of traffic analysis attacks, of the kinds likely to be feasible for authoritarian governments and their state-controlled ISPs for example.

  • Dissent seeks to offer accountable anonymity, giving users strong guarantees of anonymity while also protecting online groups or forums from anonymous abuse such as spam, Sybil attacks, and sockpuppetry. Unlike other systems, Dissent can guarantee that each user of an online forum gets exactly one bandwidth share, one vote, or one pseudonym, which other users can block in the event of misbehavior.

Dissent offers an anonymous communication substrate intended primarily for applications built on a broadcast communication model: for example, bulletin boards, wikis, auctions, or voting. Users of an online group obtain cryptographic guarantees of sender and receiver anonymity, message integrity, disruption resistance, proportionality, and location hiding.

See our CCS '10, OSDI '12, and USENIX Security '13 papers describing the experimental protocols underlying Dissent. Also feel free to check out the source code at the link below, but please keep in mind that it is an experimental prototype that is not yet ready for widespread deployment by normal users.

Communication Model

Dissent conceptually builds a "shuffled send" anonymous multicast primitive


Anytrust cloud architecture

A multi-provider, “anytrust” cloud architecture offers scalability to large anonymity sets

Conference Publications

  • No Direction Home: The True Cost of Routing Around Decoys, Amir Houmansadr, Edmund L. Wong, and Vitaly Shmatikov. NDSS 2014. Paper: Abstract, PDF.
  • Hang With Your Buddies to Resist Intersection Attacks, David Isaac Wolinsky, Ewa Syta, and Bryan Ford. CCS 2013. Paper: Abstract, PDF.
  • Ensuring High-Quality Randomness in Cryptographic Key Generation, Henry Corrigan-Gibbs, Wendy Mu, Dan Boneh, and Bryan Ford. CCS 2013. Paper: Abstract, PDF. Extended version: Abstract, PDF.
  • Proactively Accountable Anonymous Messaging in Verdict, Henry Corrigan-Gibbs, David Isaac Wolinsky, and Bryan Ford. USENIX Security 2013. Paper: Abstract, PDF. Extended version: PDF. Slides: PowerPoint, PDF.
  • The Parrot is Dead: Observing Unobservable Network Communications, Amir Houmansadr, Chad Brubaker, and Vitaly Shmatikov. Best Practical Paper Award, IEEE Security & Privacy 2013. Paper: Abstract, PDF. Slides: PowerPoint, PDF.
  • I want my voice to be heard: IP over Voice-over-IP for unobservable censorship circumvention, Amir Houmansadr, Thomas Riedl, Nikita Borisov and Andrew Singer. NDSS 2013. Paper: Abstract, PDF. Slides: PowerPoint, PDF.
  • Dissent in Numbers: Making Strong Anonymity Scale, David Isaac Wolinsky, Henry Corrigan-Gibbs, Bryan Ford, and Aaron Johnson. OSDI 2012. Paper: Abstract, PDF. Slides: PowerPoint, PDF.
  • Accountability and Deterrence in Online Life (Extended Abstract), Joan Feigenbaum, James A. Hendler, Aaron D. Jaggard, Daniel J. Weitzner, Rebecca N. Wright. WebSci11. Paper: PDF. Slides: PowerPoint, PDF.
  • Dissent: Accountable Group Anonymity, Henry Corrigan-Gibbs and Bryan Ford. CCS 2010. Paper: Abstract, PDF. Slides: PowerPoint, PDF.

Workshop Publications

  • Open vs. Closed Systems for Accountability, Joan Feigenbaum, Aaron D. Jaggard, and Rebecca N. Wright. HotSoS 2014. Paper: Abstract, PDF.
  • Crypto-Book: An Architecture for Privacy Preserving Online Identities, John Maheswaran, David Isaac Wolinsky, and Bryan Ford. HotNets 2013.
  • Conscript Your Friends into Larger Anonymity Sets with JavaScript, Henry Corrigan-Gibbs and Bryan Ford. WPES 2013 (to appear). Paper: Abstract, PDF. Extended version: PDF.
  • Reducing Latency in Tor Circuits with Unordered Delivery, Michael F. Nowlan, David Wolinsky, and Bryan Ford. FOCI 2013. Paper: Abstract, PDF. Slides: PowerPoint, PDF.
  • Welcome to the World of Human Rights: Please Make Yourself Uncomfortable, Henry Corrigan-Gibbs and Bryan Ford. CREDS 2013. Paper: PDF. Slides: PDF.
  • Scavenging for Anonymity with BlogDrop (Abstract), Henry Corrigan-Gibbs and Bryan Ford. ProvPriv 2012. Abstract: PDF. Slides: PDF.
  • Scalable Anonymous Group Communication in the Anytrust Model, David Isaac Wolinsky, Henry Corrigan-Gibbs, Bryan Ford, Aaron Johnson. EUROSEC 2012. Abstract PDF.
  • Towards a Formal Model of Accountability, Joan Feigenbaum, Aaron D. Jaggard, and Rebecca N. Wright. NSPW 2011. Paper: PDF.

Drafts and Reports

  • Seeking Anonymity in an Internet Panopticon, Joan Feigenbaum and Bryan Ford. Preprint: Abstract PDF.
  • WiNoN — Plugging the Leaky Boat of Web Anonymity, David Isaac Wolinsky and Bryan Ford. Preprint: Abstract PDF.
  • Security Analysis of Accountable Anonymous Group Communication in Dissent, Ewa Syta, Aaron Johnson, Henry Corrigan-Gibbs, Shu-Chun Weng, David Wolinsky, and Bryan Ford. Preprint: Abstract PDF.
  • On Backtracking Resistance in Pseudorandom Bit Generation, Michael J. Fischer, Michael S. Paterson, and Ewa Syta. YALEU/DCS/TR-1466, December 2012. PDF.
  • Efficient and Privacy-Preserving Biometric Authentication, Ewa Syta, David Wolinsky, Michael J. Fischer, Abraham Silberschatz, Bryan Ford, and Gina Gallegos-García. YALEU/DCS/TR-1469, November 2012. PDF.
  • Systematizing “Accountability” in Computer Science, Joan Feigenbaum, Aaron D. Jaggard, Rebecca N. Wright, Hongda Xiao. Technical Report YALEU/DCS/TR-1452, February 2012. Paper: PDF.
  • Defining "Anonymity" in Networked Communication, version 1, Joan Feigenbaum. Technical Report YALEU/DCS/TR-1448, December 2011. Paper: PDF.

Lectures

  • Hiding in a Panopticon: Grand Challenges in Internet Anonymity, keynote by Bryan Ford at NDSS Workshop on Security of Emerging Networking Technologies (SENT), February 23, 2014.
    Slides: OpenOffice PDF
  • Can You Hide in an Internet Panopticon?, presented by Bryan Ford at:
    • Tulane University, February 2013.
    • Stony Brook University, October 2013.
    • University of Texas at Austin, October 2013.
    • University of Virginia, November 2013.
    • Microsoft Research, November 2013.
    Slides: OpenOffice PDF
  • Scalable, Accountable, Traffic Analysis Resistant Anonymity in Dissent, presented by Bryan Ford at:
    • University of Texas at Austin, November 2012.
    • Cornell University, November 2012.
    • Columbia University, September 2012.
    Slides: OpenOffice PDF
  • Dissent: Accountable, Anonymous Communication on the Internet, presented by Joan Feigenbaum at:
    • Algorithms Workshop, Oxford University, October 2012.
    • University of Illinois at Chicago, April 2011.
    • Penn State University, Dec 2010.
    Slides: PDF
  • Dissent: Accountable Anonymous Group Communication, presented by Bryan Ford at:
    • Max Planck Institute for Software Systems, January 2012.
    • University of Connecticut CSE Colloquium, December 2011.
    Slides: OpenOffice PDF

Acknowledgements

This material is based upon work supported by the National Science Foundation under Grant No. CNS-0916413, and supported by the Defense Advanced Research Agency (DARPA) and SPAWAR Systems Center Pacific, Contract No. N66001-11-C-4018. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation, the Defense Advanced Research Agency (DARPA), and SPAWAR Systems Center Pacific.