Concept
Communication sécurisée
Publications associées (84)
On the Theory and Practice of Modern Secure Messaging
Billions of people now have conversations daily over the Internet. A large portion of this communication takes place via secure messaging protocols that offer "end-to-end encryption'" guarantees and resilience to compromise like the widely-used Double Ratc ...
EPFL2024Cryptographic Administration for Secure Group Messaging
Serge Vaudenay, Daniel Patrick Collins
Many real-world group messaging systems delegate group administration to the application level, failing to provide formal guarantees related to group membership. Taking a cryptographic approach to group administration can prevent both implementation and pr ...
2023Epidemic Learning: Boosting Decentralized Learning with Randomized Communication
Rachid Guerraoui, Anne-Marie Kermarrec, Sadegh Farhadkhani, Rafael Pereira Pires, Rishi Sharma, Marinus Abraham de Vos
We present Epidemic Learning ( EL ), a simple yet powerful decentralized learning (DL) algorithm that leverages changing communication topologies to achieve faster model convergence compared to conventional DL approaches. At each round of EL, each node sen ...
2023Private Message Franking with After Opening Privacy
Serge Vaudenay, Iraklis Leontiadis
Recently Grubbs et al. [GLR17] initiated the formal study of message franking protocols. This new type of service launched by Facebook, allows the receiver in a secure messaging application to verifiably report to a third party an abusive message some send ...
2023Bridging the gap between theoretical and practical privacy technologies for at-risk populations
With the pervasive digitalization of modern life, we benefit from efficient access to information and services. Yet, this digitalization poses severe privacy challenges, especially for special-needs individuals. Beyond being a fundamental human right, priv ...
EPFL2023As easy as ABC: Optimal (A)ccountable (B)yzantine (C)onsensus is easy!
Rachid Guerraoui, Jovan Komatovic, Pierre Philippe Civit, Vincent Gramoli, Seth Gilbert
In a non-synchronous system with n processes, no t(0)-resilient (deterministic or probabilistic) Byzantine consensus protocol can prevent a disagreement among correct processes if the number of faulty processes is > n - 2t(0). Therefore, the community defi ...
ACADEMIC PRESS INC ELSEVIER SCIENCE2023Moby: A Blackout-Resistant Anonymity Network for Mobile Devices
Bryan Alexander Ford, Antoine Rault, Amogh Pradeep, Hira Javaid
Internet blackouts are challenging environments for anonymity and censorship resistance. Existing popular anonymity networks (e.g., Freenet, I2P, Tor) rely on Internet connectivity to function, making them impracticable during such blackouts. In such a set ...
2022Optimal Symmetric Ratcheting for Secure Communication
Serge Vaudenay, Andrea Felice Caforio, Daniel Patrick Collins, Hailun Yan
To mitigate state exposure threats to long-lived instant messaging sessions, ratcheting was introduced, which is used in practice in protocols like Signal. However, existing ratcheting protocols generally come with a high cost. Recently, Caforio et al. pro ...
OXFORD UNIV PRESS2022Analyzing and Protecting Communication Metadata
Most communication systems (e.g., e-mails, instant messengers, VPNs) use encryption to prevent third parties from learning sensitive information.However, encrypted communications protect the contents but often leak metadata: the amount of data sent and the ...
EPFL2021Towards Efficient LPN-Based Symmetric Encryption
Serge Vaudenay, Sonia Mihaela Bogos, Dario Korolija, Thomas Locher
Due to the rapidly growing number of devices that need to communicate securely, there is still significant interest in the development of efficient encryption schemes. It is important to maintain a portfolio of different constructions in order to enable a ...
Springer International Publishing2021