Conscript Your Friends into Larger Anonymity Sets with JavaScript

Henry Corrigan-Gibbs Stanford University

Bryan Ford Yale University

Workshop on Privacy in the Electronic Society (WPES '13)
November 4, 2013, Berlin, Germany

Abstract

We present the design and prototype implementation of ConScript, a framework for using JavaScript to encourage casual Web users to participate in an anonymous communication system. When a Web user visits a cooperative Web site, the site serves a JavaScript application that instructs the browser to create and submit "dummy" messages into the anonymity system. Users who want to send non-dummy messages through the anonymity system use a browser plug-in to replace these dummy messages with real messages. Creating such conscripted anonymity sets can increase the anonymity set size available to users of remailer, e-voting, and verifiable shuffle-style anonymity systems. We outline ConScript’s architecture, we address a number of potential attacks against ConScript, and we discuss the ethical issues related to deploying such a system. Our implementation results demonstrate the practicality of ConScript: a workstation running our prototype ConScript JavaScript client generates a dummy message for a mix-net in 81 milliseconds and it generates a dummy message for a DoS-resistant DC-net in 156 milliseconds.

Proceedings version: PDF.

Extended version: PDF.

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This material is based upon work supported by the Defense Advanced Research Agency (DARPA) and SPAWAR Systems Center Pacific, Contract No. N66001-11-C-4018.