599 results
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Attaques par invariants : comment choisir les constantes de tour pour s'en protéger
Speaker : Anne Canteaut - Inria
Many lightweight block ciphers apply a very simple key schedule in which the round keys only differ by addition of a round-specific constant. Generally, there is not much theory on how to choose appropriate constants. In fact, several of those schemes were recently broken using invariant attacks, i.e. invariant subspace or nonlinear invariant attacks. This work analyzes the resistance of such[…] -
Soutenance de thèse (exceptionnellemnt lundi à 10h salle Métiviers à l'IRISA): Algorithmes de recherche sur bases de données chiffrées.
Speaker : Raphaël Bost - Université Rennes 1
La recherche sur les bases de données chiffrées vise à rendre e cace une tâche apparemment simple : déléguer le stockage de données à un serveur qui ne serait pas de con ance, tout en conservant des fonctionnalités de recherche. Avec le développement des services de stockage dans le Cloud, destinés aussi bien aux entreprises qu’aux individus, la mise au point de solutions e caces à ce problème est[…] -
On the Construction of Lightweight S-Boxes
Speaker : 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
Speaker : 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
Speaker : 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
Speaker : 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[…]