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.