527 résultats

  • 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[…]
  • Post-Quantum Cryptography Hardware: Monolithic Implementations vs. Hardware-Software Co-Design

    • 23 avril 2021

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

    Orateur : Markku-Juhani Saarinen - PQShield

    At PQShield, we've developed dedicated coprocessor(s) for lattice schemes, hash-based signatures, and code-based cryptography. These cryptographic modules are commercial rather than academic and designed to meet customer specifications such as a specific performance profile or Common Criteria and FIPS security certification requirements. Hardware implementations of legacy RSA and Elliptic Curve[…]
  • Middle-Product Learning with Rounding Problem and its Applications

    • 17 avril 2020

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

    Orateur : Katharina Boudgoust - Univ Rennes, CNRS, IRISA

    This talk focuses on a new variant of the Learning With Errors (LWE) problem, a fundamental computational problem used in lattice-based cryptography.<br/> At Crypto17, Roşca et al. introduced the Middle-Product LWE problem (MP-LWE), whose hardness is based on the hardness of the Polynomial LWE (P-LWE) problem parameterized by a large set of polynomials, making it more secure against the possible[…]
  • Comparing the difficulty of factorization and discrete logarithm: a 240-digit experiment

    • 10 avril 2020

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

    Orateur : Emmanuel Thomé - INRIA Nancy

    We report on two new records: the factorization of RSA-240, a 795-bit number, and a discrete logarithm computation over a 795-bit prime field. Previous records were the factorization of RSA-768 in 2009 and a 768-bit discrete logarithm computation in 2016. Our two computations at the 795-bit level were done using the same hardware and software, and show that computing a discrete logarithm is not[…]
  • The generalized quaternion isogeny path problem.

    • 03 avril 2020

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

    Orateur : Antonin Leroux - LIX

    The correspondence between maximal orders in a quaternion algebra and supersingular elliptic curves has uncovered new perspectives in the field of isogeny-based cryptography. The KLPT algorithm of Kohel et al. in 2014 introduces an algorithm solving the quaternion isogeny path problem in polynomial time. Studying this problem has applications both constructive and destructive. It has allowed to[…]
  • Candidats NIST basés sur les réseaux: choix de conception et astuces de ninja

    • 25 mars 2020

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

    Orateur : Thomas Prest. - PQShield

    Parmi les 26 schémas post-quantique toujours considérés pour standardisation par le NIST, 12 sont basés sur les réseaux (3 schémas de signature et 9 schémas de chiffrement). Cette présentation leur est consacrée. A haut niveau, tous peuvent être interprétés comme des instanciations directes de paradigmes bien établis. Mais une analyse plus attentive révèle que chacun d'eux fait des choix de[…]