624 résultats

  • Isogenies over Hessian Model of Elliptic Curves

    • 03 juin 2022

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

    Orateur : Emmanuel Fouotsa - Université de Bamenda

    In this talk we present explicit formulas for isogenies between elliptic curves in (twisted) Hessian form. We examine the numbers of operations in the base field to compute the formulas. In comparison with other isogeny formulas, we note that the obtained formulas for twisted Hessian curves have the lowest costs for processing the kernel and the X-affine formula has the lowest cost for processing[…]
  • New uses in Symmetric Cryptography: from Cryptanalysis to Designing

    • 20 mai 2022

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

    Orateur : Clémence Bouvier - INRIA

    New symmetric primitives are being designed to be run in abstract settings such as Multi-Party Computations (MPC) or Zero-Knowledge (ZK) proof systems. More particularly, these protocols have highlighted the need to minimize the number of multiplications performed by the primitive in large finite fields.<br/> As the number of such primitives grows, it is important to better understand the[…]
  • Port Contention Goes Portable: Port Contention Side Channels in Web Browsers

    • 13 mai 2022

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

    Orateur : Thomas Rokicki (Univ Rennes, CNRS, IRISA)

    Microarchitectural side-channel attacks can derive secrets from the execution of vulnerable programs. Their implementation in web browsers represents a considerable extension of their attack surface, as a user simply browsing a malicious website, or even a malicious third-party advertisement in a benign cross-origin isolated website, can be a victim.In this talk, we present the first CPU port[…]
  • Security challenges and opportunities in emerging device technologies: a case study on flexible electronics

    • 06 mai 2022

    • Inria Center of the University of Rennes - Espace de conférences

    Orateur : Nele Mentens - KU Leuven, Belgium

    While traditional chips in bulk silicon technology are widely used for reliable and highly ef?cient systems, there are applications that call for devices in other technologies. On the one hand, novel device technologies need to be re-evaluated with respect to potential threats and attacks, and how these can be faced with existing and novel security solutions and methods. On the other hand,[…]
  • On Rejection Sampling in Lyubashevsky's Signature Scheme

    • 06 mai 2022

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

    Orateur : Julien Devevey - ENS de Lyon

    Lyubashevsky’s signatures are based on the Fiat-Shamir with aborts paradigm, whose central ingredient is the use of rejection sampling to transform (secret-key-dependent) signature samples into samples from a secret-key-independent distribution. The choice of these two underly- ing distributions is part of the rejection sampling strategy, and various instantiations have been considered up to this[…]
  • Side Channel Analysis: Instruction extraction and Information estimation

    • 06 mai 2022

    • CEA-LETI; Université de Montpellier, LIRMM - Salle Pétri/Turing

    Orateur : Valence Cristiani

    Side-channel usually aims at extracting cryptographic secrets from electronic devices through their physical leakages. However, these channels can leak other sensitive information. The first part of this talk will present a study of side channel-based disassembling (SCBD) that aims to recover instructions executed by a microcontroller. The main threat represented by SCBD is that it potentially[…]