MARSHAL: Messaging with Asynchronous Ratchets and Signatures for faster HeALing - Université Clermont Auvergne Access content directly
Conference Papers Year : 2022

MARSHAL: Messaging with Asynchronous Ratchets and Signatures for faster HeALing

Abstract

Secure messaging applications are deployed on devices that can be compromised, lost, stolen, or corrupted in many ways. Thus, recovering from attacks to get back to a clean state is essential and known as healing. Signal is a widely-known, privacy-friendly messaging application, that uses key-ratcheting mechanism updates keys at each stage to provide end-to-end channel security, forward secrecy, and post-compromise security. We strengthen this last property, by providing a faster healing. Signal needs up to two full chains of messages before recovering, our protocol enables recovery after the equivalent of a chain of only one message. We also provide an extra protection against session-hijacking attacks. We do so, while building on the pre-existing Signal backbone, without weakening its other security assumptions, and still being compatible with Signal's out-of-order message handling feature. Our implementation results show that, while slower than Signal (as expected), MARSHAL's spectacular gain in healing speed comes at a surprisingly low cost, with individual stages (including keyderivation, encryption, and decryption) taking less than 6 ms.
Fichier principal
Vignette du fichier
main.pdf (146.15 Ko) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

hal-03510612 , version 1 (04-01-2022)

Licence

Attribution

Identifiers

Cite

Olivier Blazy, Pierre-Alain Fouque, Thibaut Jacques, Pascal Lafourcade, Cristina Onete, et al.. MARSHAL: Messaging with Asynchronous Ratchets and Signatures for faster HeALing. The 37th ACM/SIGAPP Symposium on Applied Computing, SAC (2022), Apr 2022, Virtual, Czech Republic. pp.1-8, ⟨10.1145/3477314.3507044⟩. ⟨hal-03510612⟩
155 View
333 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More