Filtrer par type de contenu
Sélectionnez un ou plusieurs filtres. Ce choix permettra de recharger la page pour afficher les résultats filtrés.
716 résultats
-
-
Séminaire
-
Cryptographie
Implicit proofs of membership
Orateur : Olivier Blazy - Université Limoges
Smooth hash proof systems have been introduced by Cramer and shoup to build compact efficient cca2 encryption in the standard model. Since then, they found applications in a broad range of protocols from oblivious transfer to authenticated key exchange, passing by witness examples.<br/> In this talk, we will start by a panorama of languages that can be managed by such a primitive and then show how[…] -
-
-
Séminaire
-
Cryptographie
A Concrete Treatment of Efficient Continuous Group Key Agreement via Multi-Recipient PKEs
Orateur : Thomas Prest - PQShield
Continuous group key agreements (CGKAs) are a class of protocols that can provide strong security guarantees to secure group messaging protocols such as Signal and MLS. Protection against device compromise is provided by commit messages: at a regular rate, each group member may refresh their key material by uploading a commit message, which is then downloaded and processed by all the other members[…] -
-
-
Séminaire
-
Cryptographie
Middle-Product Learning with Rounding Problem and its Applications
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[…] -
-
-
Séminaire
-
Cryptographie
Soutenance de thèse: Conception de courbes elliptiques et applications
Orateur : Rémi Clarisse - Rennes
Le thème de la sécurité de l’information est prédominant dans nos vies actuelles. En particulier, les utilisateurs de service, plus précisément en ligne, s’attendent de plus en plus à ce que leurs données à caractère personnel soient traitées dignement et avec leur consentement. Cela incite donc à concevoir des systèmes se pliant à de telles exigences. Le recours à la cryptographie permet de[…] -
-
-
Séminaire
-
Cryptographie
Traceable Constant-Size Multi-Authority Credentials
Orateur : Chloé Hébant - ENS
Many attribute-based anonymous credential (ABC) schemes have been proposed allowing a user to prove the possession of some attributes, anonymously. They became more and more practical with, for the most recent papers, a constant-size credential to show a subset of attributes issued by a unique credential issuer. However, proving possession of attributes coming from K different credential issuers[…] -
-
-
Séminaire
-
Cryptographie
Computing isogenies from modular equations in genus 2
Orateur : Jean Kieffer - Université Bordeaux 1
Given two l-isogenous elliptic curves, a well-known algorithm of Elkies uses modular polynomials to compute this isogeny explicitly. In this work, we generalize his ideas to Jacobians of genus 2 curves. Our algorithms works for both l-isogenies and (in the RM case) cyclic isogenies, and uses Siegel or Hilbert type modular equations respectively. This has applications for point counting in genus 2:[…] -