624 results

  • How fast do you heal? A taxonomy for post-compromise security in secure-channel establishment.

    • November 10, 2023

    • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

    Speaker : Léo Robert - Université d'Amiens

    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 features in prominent messaging protocols such as Signal. In this[…]
  • An extension of Overbeck’s attack with an application to cryptanalysis of Twisted Gabidulin-based schemes.

    • October 06, 2023

    • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

    Speaker : Ilaria Zappatore - XLIM

    In this talk, I will discuss the decoding of Gabidulin and related codes from a cryptographic point of view, pointing out that these codes can be decoded solely from the knowledge of a generator matrix. I will also present an extension of Gibson and Overbeck attacks on the generalized GPT encryption scheme (instantiated with the Gabidulin code) for different ranks of the distortion matrix. Finally[…]
  • ECDSA White-Box Implementations, Feedback on CHES 2021 WhibOx Contest

    • September 29, 2023

    • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

    Speaker : Agathe Houzelot - Idemia

    Cryptographic algorithms are primarily designed to be secure in the black-box model, where an attacker can only observe their input/output behavior. However in practice, algorithms are rarely executed in a completely isolated environment and additional information is often leaked. In the context of mobile applications or connected objects, devices often lack secure storage to protect secret keys,[…]
  • Generic Attack on Duplex-Bases AEAD Modes using Random Function Statistics

    • September 22, 2023

    • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

    Speaker : Rachelle Heim Boissier - Inria

    Duplex-based authenticated encryption modes with a sufficiently large key length are proven to be secure up to the birthday bound 2^(c/2), where c is the capacity. However this bound is not known to be tight and the complexity of the best known generic attack, which is based on multicollisions, is much larger: it reaches 2^c/α where α represents a small security loss factor. There is thus an[…]
  • Modélisation statistique et sécurité des générateurs d'aléa pour la cryptographie

    • April 08, 2023 (11:00 - 12:00)

    • À l'IRISA, campus de Beaulieu, Rennes

    Speaker : David Lubicz - DGA, IRMAR

    Dans cet exposé on essaie d'expliquer ce que l'on entend pas méthodes statistiques et on donne des exemples concrets d'application dans la cybersécurité.
    • Cryptography

  • Analyse statistique des extrêmes pour la modélisation d'évènements rares ou atypiques

    • April 08, 2023 (10:00 - 11:00)

    • À l'IRISA, campus de Beaulieu, Rennes

    Speaker : Gilles Stupfler - ENSAI