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 group-oriented anonymous communication best suited for broadcast communication: for example, bulletin boards, wikis, auctions, or voting. Members of a group obtain cryptographic guarantees of sender and receiver anonymity, message integrity, disruption resistance, proportionality, and location hiding.

For a high-level overview of Dissent and where it fits among various approaches to anonymous communication, see our article Seeking Anonymity in an Internet Panopticon, in Communications of the ACM. For technical details we recommend starting with 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 to the right, keeping in mind that it is an experimental prototype and 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 and Journal Publications

  • Riffle: An Efficient Communication System With Strong Anonymity, Albert Kwon, David Lazar, Srinivas Devadas, and Bryan Ford. PETS 2016. Paper: Abstract PDF.
  • Keeping Authorities “Honest or Bust” with Decentralized Witness Cosigning, Ewa Syta, Iulia Tamas, Dylan Visher, David Isaac Wolinsky, Philipp Jovanovic, Linus Gasser, Nicolas Gailly, Ismail Khoffi, and Bryan Ford. IEEE S&P 2016. Paper: Abstract PDF. Slides: LibreOffice, PDF.
  • AnonRep: Towards Tracking-Resistant Anonymous Reputation, Ennan Zhai, David Isaac Wolinsky, Ruichuan Chen, Ewa Syta, Chao Teng, and Bryan Ford. NSDI 2016. Paper: Abstract PDF. Slides: PDF.
  • Building Privacy-Preserving Cryptographic Credentials from Federated Online Identities, John Maheswaran, Daniel Jackowitz, Ennan Zhai, David Isaac Wolinsky, and Bryan Ford. CODASPY 2016. Paper: Abstract PDF.
  • Private Eyes: Secure Remote Biometric Authentication, Ewa Syta, Michael J. Fischer, David Wolinsky, Abraham Silberschatz, Gina Gallegos-Garcia, and Bryan Ford. SECRYPT 2015. Paper: PDF. Slides: PowerPoint.
  • 20,000 In League Under the Sea: Anonymous Communication, Trust, MLATs, and Undersea Cables, Aaron D. Jaggard, Aaron Johnson, Sarah Cortes, Paul Syverson, and Joan Feigenbaum. PETS 2015. PDF.
  • Managing NymBoxes for Identity and Tracking Protection, David Isaac Wolinsky, Daniel Jackowitz, and Bryan Ford. TRIOS 2014. Abstract PDF.
  • Security Analysis of Accountable Anonymity in Dissent, Ewa Syta, Aaron Johnson, Henry Corrigan-Gibbs, Shu-Chun Weng, David Wolinsky, and Bryan Ford. TISSEC, Volume 17 Issue 1, August 2014. Full version: Abstract PDF.
  • CloudTransport: Using Cloud Storage for Censorship-Resistant Networking, Chad Brubaker, Amir Houmansadr, and Vitaly Shmatikov. PETS 2014. Paper: PDF.
  • 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.

Drafts and Reports

  • Seeking Anonymity in an Internet Panopticon, Joan Feigenbaum and Bryan Ford. To appear in Communications of the ACM. Preprint: Abstract PDF.
  • Crypto-Book: Bootstrapping Privacy Preserving Online Identities from Social Networks, John Maheswaran, Daniel Jackowitz, David Isaac Wolinsky, Lining Wang, 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.

Popular Media Coverage

Workshop Publications

  • Multiple Objectives of Lawful-Surveillance Protocols, Joan Feigenbaum and Bryan Ford. SPW 2017. Paper: Abstract PDF
  • PriFi: A Low-Latency and Tracking-Resistant Protocol for Local-Area Anonymous Communication, Ludovic Barman, Mahdi Zamani, Italo Dacosta, Joan Feigenbaum, Bryan Ford, Jean-Pierre Hubaux, and David Wolinsky. WPES 2016. Paper: Abstract PDF
  • Privacy-Preserving Lawful Contact Chaining, Aaron Segal, Joan Feigenbaum, and Bryan Ford. WPES 2016. Paper: Abstract PDF
  • Certificate Cothority: Towards Trustworthy Collective CAs, Ewa Syta, Iulia Tamas, Dylan Visher, David Isaac Wolinsky, and Bryan Ford. HotPETS 2015. Paper: PDF. Slides: PowerPoint, PDF.
  • Catching Bandits and Only Bandits: Privacy-Preserving Intersection Warrants for Lawful Surveillance, Aaron Segal, Bryan Ford, and Joan Feigenbaum. FOCI 2014. Paper: Abstract, PDF.
  • From Onions to Shallots: Rewarding Tor Relays with TEARS, Rob Jansen, Andrew Miller, Paul Syverson, and Bryan Ford. HotPETS 2014. Paper: Abstract, PDF.
  • A TorPath to TorCoin: Proof-of-Bandwidth Altcoins for Compensating Relays, Mainak Ghosh, Miles Richardson, Bryan Ford, and Rob Jansen. HotPETS 2014. Paper: Abstract, PDF.
  • Representing Network Trust and Using It to Improve Anonymous Communication, Aaron D. Jaggard, Aaron Johnson, Paul Syverson, and Joan Feigenbaum. HotPETS 2014. Paper: Abstract, PDF.
  • 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. Paper: Abstract PDF
  • Conscript Your Friends into Larger Anonymity Sets with JavaScript, Henry Corrigan-Gibbs and Bryan Ford. WPES 2013. 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.
  • Faceless: decentralized anonymous group messaging for online social networks, Xiaoxiao Song, David Isaac Wolinsky, and Bryan Ford. SNS 2012. Paper: 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.

Lectures

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.