627 résultats

  • On the Construction of Lightweight S-Boxes

    • 15 décembre 2017

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

    Orateur : Sébastien Duval - INRIA Paris-Rocquencourt

    S-Boxes are essential objects in the conception of blockciphers. Typically, an S-Box is simply a permutation (bijective function) on n bits, with n small (usually 4 or 8). Its role in a blockcipher is to bring nonlinearity to the cipher, thus an S-Box must be highly nonlinear. Several parameters of a function are used to measure nonlinearity, among which the most important are differential[…]
  • Identification d'Algorithmes Cryptographiques dans du Code Natif

    • 12 décembre 2017

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

    Orateur : Pierre Lestringant - Soutenance de thèse à 14h en salle Métivier (IRISA)

    Durant ma thèse j’ai travaillé à la conception de méthodes automatisées permettant l’identification d’algorithmes cryptographiques dans des programmes compilés en langage machine. Ce besoin bien spécifique trouve une partie de son origine dans le domaine de l’évaluation logicielle. L’utilisation d’algorithmes cryptographiques se fait dans le but d’obtenir des fonctions de sécurité telles que la[…]
  • Class Group Computations in Number Fields and Applications to Cryptology

    • 08 décembre 2017

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

    Orateur : Alexandre Gelin - Versailles-Saint-Quentin-en-Yvelines

    In this talk, we focus on class group computations in number fields. We start by describing an algorithm for reducing the size of a defining polynomial of a number field. There exist infinitely many polynomials that define a specific number field, with arbitrarily large coefficients, but our algorithm constructs the one that has the absolutely smallest coefficients. The advantage of knowing such a[…]
  • Towards the Implementation of Efficient and Distributable Pairing-based Crypto Library

    • 01 décembre 2017

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

    Orateur : Al-Amin Khandaker - Okayama University

    Pairing-based cryptography is popular among the cryptographic protocol researchers for its eccentric provable security. Protocol side researchers often see pairing as a black box. They often need to test the correctness of their proposal. Typically, mathematicians and cryptography engineers try to make the underlying operations of pairing-based crypto efficient. In addition, different types of[…]
  • Lilliput: Advances in Security and Performance Analysis

    • 17 novembre 2017

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

    Orateur : Julien Francq - Airbus CyberSecurity

    Lilliput is a block cipher that has been published in 2015 in IEEE Transactions in Computers with Thierry Berger and Marine Minier, and the seminal paper has been cited 6 times for now. This talk will summarize the results of the third-party cryptanalysis and implementations, and will show that Lilliput is still an efficient and secure cryptographic primitives.
  • CRYSTALS: Dilithium and Kyber

    • 10 novembre 2017

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

    Orateur : Damien Stehlé - ENS de Lyon

    Kyber -- a Key Exchange Mechanism -- and Dilithium -- a digital signature -- are the two components of the Cryptographic Suite for Algebraic Lattices (CRYSTALS). I will present the intractable problems underlying their security, overview their design and comment their practical performance. The talk is based on the following articles:<br/> https://eprint.iacr.org/2017/633.pdf<br/&gt; https:/[…]