Olivier Blazy, LIX, CNRS, Inria, École Polytechnique, Institut Polytechnique de Paris, France; Ioana Boureanu, University of Surrey, Surrey Centre for Cyber Security, UK; Pascal Lafourcade, LIMOS, University of Clermont Auvergne, France; Cristina Onete, XLIM, University of Limoges, France; Léo Robert, LIMOS, University of Clermont Auvergne, France
Post-Compromise Security (PCS) is a property of secure-channel establishment schemes, which limits the security breach of an adversary that has compromised one of the endpoint to a certain number of messages, after which the channel heals. An attractive property, especially in view of Snowden’s revelation of mass-surveillance, PCS was pioneered by the Signal messaging protocol, and is present in OTR. In this paper, we introduce a framework for quantifying and comparing PCS security, with respect to a broad taxonomy of adversaries. The generality and flexibility of our approach allows us to model the healing speed of a broad class of protocols, including Signal, but also an identity-based messaging protocol named SAID, and even a composition of 5G handover protocols.
Open Access Media
USENIX is committed to Open Access to the research presented at our events. Papers and proceedings are freely available to everyone once the event begins. Any video, audio, and/or slides that are posted after the event are also free and open to everyone. Support USENIX and our commitment to Open Access.
author = {Olivier Blazy and Ioana Boureanu and Pascal Lafourcade and Cristina Onete and L{\'e}o Robert},
title = {How fast do you heal? A taxonomy for post-compromise security in secure-channel establishment},
booktitle = {32nd USENIX Security Symposium (USENIX Security 23)},
year = {2023},
isbn = {978-1-939133-37-3},
address = {Anaheim, CA},
pages = {5917--5934},
url = {https://www.usenix.org/conference/usenixsecurity23/presentation/blazy},
publisher = {USENIX Association},
month = aug
}