CryptoDB
Metadata Protection for MLS and Its Variants
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| Download: | |
| Presentation: | Slides |
| Abstract: | In this talk, we first systematically analyze the privacy offered by Signal and MLS and observe a critical shortcoming of MLS compared to Signal. In short, MLS leaks much more _metadata_ than Signal. In privacy-critical scenarios, dismissing this metadata leakage puts at risk the users who may otherwise believe that MLS offers the exact same level of security as Signal. We then propose an efficient and provably secure solution to bootstrap the current MLS to be as metadata-hiding (or, in some metrics, even more) as Signal. Our key insight is to leverage the existence of a _unique_ continuously evolving group secret key shared by the group to perform an anonymous membership authentication protocol. |
| Video: | https://youtu.be/sthXs4zJ5XU?t=4522 |
BibTeX
@misc{rwc-2023-35457,
title={Metadata Protection for MLS and Its Variants},
note={Video at \url{https://youtu.be/sthXs4zJ5XU?t=4522}},
howpublished={Talk given at RWC 2023},
author={Shuichi Katsumata and Thomas Prest and Keitaro Hashimoto},
year=2023
}