MCMix: Anonymous Messaging via Secure Multiparty Computation

Nikolaos Alexopoulos, Aggelos Kiayias, Riivo Talviste, Thomas Zacharias

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We present MCMix, an anonymous messaging system that completely hides communication metadata and can scale in the order of hundreds of thousands of users. Our approach is to isolate two suitable functionalities, called dialing and conversation, that when used in succession realize anonymous messaging. With this as a starting point, we apply secure multiparty computation (MPC) and proceed to realize them. We present an implementation using a popular MPC system (Sharemind) that is competitive in terms of latency with previous messaging systems that only offer much weaker privacy guarantees. Our solution can be instantiated in a variety of different ways with different MPC implementations, overall illustrating how MPC is a viable and competitive alternative to mix-nets and DC-nets for anonymous communication.
Original languageEnglish
Title of host publicationProceedings of the 26th USENIX Security Symposium
PublisherUSENIX Association
Number of pages18
ISBN (Print)978-1-931971-40-9
Publication statusPublished - 18 Aug 2017
Event26th USENIX Security Symposium - Sheraton Vancouver Wall Centre Hotel, Vancouver, Canada
Duration: 16 Aug 201718 Aug 2017
Conference number: 26


Conference26th USENIX Security Symposium
Internet address


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