627 results
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Evaluation embarquée de l'entropie d'un générateur d'aléa pour la cryptographie
Speaker : David Lubicz - DGA et IRMAR
Dans cet exposé, nous présentons une méthode de mesure embarquée de la composante thermique du jitter de phase d'un couple d'anneaux d'oscillateurs : cette mesure est nécessaire pour calculer le taux d'entropie d'un générateur d'aléa physique basé sur des anneaux oscillants. La précision de cette mesure dont le principe repose sur un algorithme de type Monte-Carlo dépend de l' équidistribution de[…] -
Password-Authenticated Key Exchange (PAKE) from Isogenies
Speaker : Sabrina Kunzweiler - Université Bordeaux
The passwords that we use in our everyday life are often chosen to be easily memorable which makes them vulnerable to attacks. This problem is addressed by password-authenticated key exchange (PAKE). The general idea is to enable two parties who share the same (potentially weak) password to establish a strong session key. Most PAKE protocols used today are based on Diffie-Hellman key exchange in[…] -
Finding short integer solutions when the modulus is small
Speaker : Eamonn Postlethwaite - King's College London
We present cryptanalysis of the inhomogenous short integer solution (ISIS) problem for anomalously small moduli by exploiting the geometry of BKZ reduced bases of q-ary lattices. We apply this cryptanalysis to examples from the literature where taking such small moduli has been suggested. A recent work [Espitau–Tibouchi–Wallet–Yu, CRYPTO 2022] suggests small versions of the lattice signature[…] -
How fast do you heal? A taxonomy for post-compromise security in secure-channel establishment.
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.
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
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,[…]