Filtrer par type de contenu

Sélectionnez un ou plusieurs filtres. Ce choix permettra de recharger la page pour afficher les résultats filtrés.

Supprimer tous les filtres

634 résultats

    • Séminaire

    • Cryptographie

    Lattice-based signatures: from construction to implementation

    • 29 novembre 2019

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

    Orateur : Pauline Bert - soutenance de thèse, amphi P de l'ISTIC, 14h

    Lattice-based cryptography is one of the major line of research to build post-quantum public key primitives. In this thesis, we discuss about digital signatures constructions and their implementation. We first describe a Fiat-Shamir transformation from an identification scheme using rejection sampling to a digital signature secure in the random oracle model. Then we describe an identity-based[…]
    • Séminaire

    • Cryptographie

    Code-based postquantum cryptography : candidates to standardization

    • 23 avril 2021

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

    Orateur : Nicolas Sendrier - INRIA

    At the third round of the NIST standardization process, three candidates remain with a security based on error correcting codes, all are key exchange mechanisms. We will explore them according to their security assumptions and properties. Among them, we find an historical scheme (Classic McEliece), as well as schemes using sparse and quasi-cyclic matrices (BIKE and HQC). We will examine pros and[…]
    • Séminaire

    • Cryptographie

    Soutenance de thèse: Problème du logarithme discret sur des courbes elliptiques

    • 28 janvier 2022

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

    Orateur : Andy Russon - Rennes 1 et Orange

    L’usage des courbes elliptiques en cryptographie s’est largement répandu pour assurer la sécurité des communications ou de transactions financières. Cela est dû notamment au fait que la sécurité repose sur la difficulté du problème du logarithme discret qui permet d’utiliser les courbes elliptiques avec des paramètres qui assurent une efficacité.<br/> Dans cette thèse, nous abordons[…]
    • Séminaire

    • Cryptographie

    Cryptanalysis of code-based cryptosystems using the square-code distinguisher

    • 07 février 2020

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

    Orateur : Mathieu Lequesne - INRIA

    Many code-based cryptosystems have been proposed recently, especially in response to the call for post-quantum cryptography standardization issued by the National Institute of Standards and Technologie. Most code-based cryptosystem rely on the same idea: an error-correcting code with some special structural properties (including good error-correction capacity) serves as the private key. This code[…]
    • Séminaire

    • Cryptographie

    Decoding Supercodes of Gabidulin Codes and Applications to Cryptanalysis

    • 22 octobre 2021

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

    Orateur : Maxime Bombar - Ecole Polytechnique

    Error correcting codes are well known to provide possible candidates for building quantum safe cryptographic primitives. Besides the Hamming metric which has a long-standing history, one may consider other metrics such as the rank metric. Gabidulin codes are the rank metric analogue of Reed-Solomon codes and can be efficiently decoded up to half the minimum distance. However, beyond this radius,[…]
    • Séminaire

    • Cryptographie

    Learning With Errors and Extrapolated Dihedral Cosets Problem

    • 23 février 2018

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

    Orateur : Weiqiang Wen - ENS de Lyon

    The hardness of the learning with errors (LWE) problem is one of the most fruitful resources of modern cryptography. In particular, it is one of the most prominent candidates for secure post-quantum cryptography. Understanding its quantum complexity is therefore an important goal. We show that under quantum polynomial time reductions, LWE is equivalent to a relaxed version of the dihedral coset[…]