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

    Towards Trustworthy Electronic Voting Systems

    • 11 décembre 2009

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

    Orateur : Jacques Traoré - France telecom

    We will focus on this talk on electronic voting which emulates traditional voting in a networked environment. We will first introduce the model of electronic voting. In particular, we will present the security requirements that an electronic voting system must fulfil in order to be a proper substitute for a paper-ballot system. We will also briefly review the cryptographic tools generally used to[…]
    • Séminaire

    • Cryptographie

    Quelques aspects algorithmiques de la cryptographie

    • 14 novembre 2008

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

    Orateur : David Lubicz - DGA et Université Rennes I

    La cryptographie à clef publique, qui fut inventée dans les années soixante-dix par W. Diffie et M. Hellman, apporte par rapport à la cryptographie symétrique un certain nombre de fonctionnalités particulièrement intéressantes pour les applications pratiques. Sa mise en oeuvre repose le plus souvent sur la difficulté calculatoire de certains problèmes issus de la théorie des nombres. De là, on[…]
    • Séminaire

    • Cryptographie

    An infinite class of balanced functions with optimal algebraic

    • 24 avril 2009

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

    Orateur : Claude Carlet - Université Paris 8

    Travail en commun avec Keqin Feng, Tsinghua University, Pékin.<br/> After the improvement by Courtois and Meier of the algebraic attacks on stream ciphers and the introduction of the related notion of algebraic immunity, several constructions of infinite classes of Boolean functions with optimum algebraic immunity have been proposed. All of them gave functions whose algebraic degrees are[…]
    • Séminaire

    • Cryptographie

    Breaking the F-FCSR-H stream cipher in real time

    • 16 janvier 2009

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

    Orateur : Thomas Johanson - Lund University

    The F-FCSR stream cipher family has been presented a few years ago. Apart from some flaws in the initial propositions, corrected in a later stage, there are no known weaknesses of the core of these algorithms. The hardware oriented version, called FCSR-H, is one of the ciphers selected for the eSTREAM portfolio. In this paper we present a new and severe cryptanalytic attack on the F-FCSR stream[…]
    • Séminaire

    • Cryptographie

    Key Recovery Attacks of Practical Complexity on AES Variants With Up To 10 Rounds

    • 25 septembre 2009

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

    Orateur : Orr Dunkelman - ENS

    AES is the best known and most widely used block cipher. Its three versions (AES-128, AES-192, and AES-256) differ in their key sizes (128 bits, 192 bits and 256 bits) and in their number of rounds (10, 12, and 14, respectively). In the case of AES-128, there is no known attack which is faster than the 2^{128} complexity of exhaustive search. However, AES-192 and AES-256 were recently shown to be[…]
    • Séminaire

    • Cryptographie

    Hardware Operators for Pairing-Based Cryptography

    • 13 mars 2009

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

    Orateur : Jean-Luc Beuchat - University of Tsukuba

    This talk is devoted to the design of fast parallel accelerators for the cryptographic Tate pairing. We propose here a novel hardware implementation of Miller's loop based on a pipelined Karatsuba-Ofman multiplier. Thanks to a careful choice of the mean of computing the Tate pairing and algorithms for tower field arithmetic, we manage to keep the pipeline busy. We also describe the strategies[…]