Saba Eskandarian (University of North Carolina at Chapel Hill), Dan Boneh (Stanford University)

This paper studies the role of multiparty shuffling protocols in enabling more efficient metadata-hiding communication. We show that the process of shuffling messages can be expedited by having servers collaboratively shuffle and verify secret-shares of messages instead of using a conventional mixnet approach where servers take turns performing independent verifiable shuffles of user messages. We apply this technique to achieve both practical and asymptotic improvements in anonymous broadcast and messaging systems. We first show how to build a three server anonymous broadcast scheme, secure against one malicious server, that relies only on symmetric cryptography. Next, we adapt our three server broadcast scheme to a k-server scheme secure against k-1 malicious servers, at the cost of a more expensive per-shuffle preprocessing phase. Finally, we show how our scheme can be used to significantly improve the performance of the MCMix anonymous messaging system.

We implement our shuffling protocol in a system called Clarion and find that it outperforms a mixnet made up of a sequence of verifiable (single-server) shuffles by 9.2x for broadcasting small messages and outperforms the MCMix conversation protocol by 11.8x.

View More Papers

Demo #14: In-Vehicle Communication Using Named Data Networking

Zachariah Threet (Tennessee Tech), Christos Papadopoulos (University of Memphis), Proyash Poddar (Florida International University), Alex Afanasyev (Florida International University), William Lambert (Tennessee Tech), Haley Burnell (Tennessee Tech), Sheikh Ghafoor (Tennessee Tech) and Susmit Shannigrahi (Tennessee Tech)

Read More

Fuzzing Configurations of Program Options

Zenong Zhang (University of Texas at Dallas), George Klees (University of Maryland), Eric Wang (Poolesville High School), Michael Hicks (University of Maryland), Shiyi Wei (University of Texas at Dallas)

Read More

ditto: WAN Traffic Obfuscation at Line Rate

Roland Meier (ETH Zürich), Vincent Lenders (armasuisse), Laurent Vanbever (ETH Zürich)

Read More

Testability Tarpits: the Impact of Code Patterns on the...

Feras Al Kassar (SAP Security Research), Giulia Clerici (SAP Security Research), Luca Compagna (SAP Security Research), Davide Balzarotti (EURECOM), Fabian Yamaguchi (ShiftLeft Inc)

Read More