624 résultats

  • 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[…]
  • Contemporary Issues in Digital Forensics

    • 31 janvier 2020

    • Inria Center of the University of Rennes - - Petri/Turing room

    Orateur : Ben Martini (University of South Australia)

    The discipline of digital forensics, or as it was then known ‘forensic computing’, began with a focus on retrieving admissible evidence from computer systems (typically personal computers). However, with the increased pervasiveness of connected digital technologies in the last 20 years, a wide variety of new and complex sources of digital evidence have emerged. This has presented a range of[…]
  • Constant time techniques for lattice based cryptography

    • 24 janvier 2020

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

    Orateur : Melissa Rossi - École normale supérieure, CNRS, PSL University, Inria

    NIST’s post-quantum cryptography competition has entered in its second phase, the time has come to focus more closely on practical aspects of the candidates. On the lattice-based side, certain schemes chose to implement discrete Gaussian distributions which allow better parameters and security reductions. However, this advantage has also proved to be their Achilles’ heel, as discrete Gaussians[…]
  • The Revival of Quadratic Fields Cryptography

    • 17 janvier 2020

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

    Orateur : Guilhem Castagnos - Université Bordeaux 1

    More than 30 years ago, Buchmann and Williams proposed using ideal class groups of imaginary quadratic fields in cryptography with a Diffie-Hellman style key exchange protocol. After several twists, there has been in recent years a new interest in this area. This rebirth is mainly due to two features. First, class groups of imaginary quadratic fields allow the design of cryptographic protocols[…]
  • Computing isogenies from modular equations in genus 2

    • 10 janvier 2020

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

    Orateur : Jean Kieffer - Université Bordeaux 1

    Given two l-isogenous elliptic curves, a well-known algorithm of Elkies uses modular polynomials to compute this isogeny explicitly. In this work, we generalize his ideas to Jacobians of genus 2 curves. Our algorithms works for both l-isogenies and (in the RM case) cyclic isogenies, and uses Siegel or Hilbert type modular equations respectively. This has applications for point counting in genus 2:[…]
  • Vers une meilleure compréhension de l’apprentissage profond appliqué aux attaques par observation

    • 10 janvier 2020

    • CEA - Salle Métivier

    Orateur : Loïc Masure

    Les attaques par observation (SCA) exploitent les failles d’une primitive cryptographique embarquée sur un composant (type carte à puce, IoT, …), en mesurant des grandeurs physiques qui dépendent indirectement de la valeur de la clé secrète. C’est pourquoi il est primordial pour les développeurs de proposer des contre-mesures adaptées et d’évaluer leur efficacité face à un attaquant potentiel.Au[…]