Filtrer par type de contenu
Sélectionnez un ou plusieurs filtres. Ce choix permettra de recharger la page pour afficher les résultats filtrés.
719 résultats
-
-
Séminaire
-
Cryptographie
Soutenance de thèse: Problème du logarithme discret sur des courbes elliptiques
Orateur : Andy Russon - Rennes 1 et Orange
L’usage des courbes elliptiques en cryptographie s’est largement répandu pour assurer la sécurité des communications ou de transactions financières. Cela est dû notamment au fait que la sécurité repose sur la difficulté du problème du logarithme discret qui permet d’utiliser les courbes elliptiques avec des paramètres qui assurent une efficacité.<br/> Dans cette thèse, nous abordons principalement[…] -
-
-
Séminaire
-
Cryptographie
Aggregate Cash Systems: A Cryptographic Investigation of Mimblewimble
Orateur : Michele Orru - ENS
-
-
-
Séminaire
-
Cryptographie
Cocks-Pinch curves of embedding degree five to eight and optimal ate pairing computation
Orateur : Simon Masson - Loria, Nancy
Recent algorithmic improvements of discrete logarithm computation in special extension fields threaten the security of pairing-friendly curves used in practice. A possible answer to this delicate situation is to propose alternative curves that are immune to these attacks, without compromising the efficiency of the pairing computation too much. We follow this direction, and focus on embedding[…] -
-
-
Séminaire
-
Cryptographie
CSIDH: an efficient post-quantum commutative group action
Orateur : Chloé Martindale - Technical University of Eindhoven
CSIDH, or `commutative supersingular isogeny Diffie-Hellman' is a new isogeny-based protocol of Castryck, Lange, Martindale, Panny, and Renes.<br/> The Diffie-Hellman style scheme resulting from the group action allows for public key validation at very little cost, runs reasonably fast in practice, and has public keys of only 64 bytes at a conjectured AES-128 security level, matching NIST’s post[…] -
-
-
Séminaire
-
Cryptographie
Isogeny-based cryptography from superspecial genus-2 curves
Orateur : Wouter Castryck - KU Leuven
I will report on some first attempts to do isogeny-based cryptography in genus 2. More precisely, we will use isogeny graphs of superspecial principally polarized abelian surfaces over GF(p^2) for constructing variants of Charles, Goren and Lauter's hash function and of Jao and De Feo's SIDH key exchange protocol, both of which use supersingular elliptic curves over GF(p^2). This will be largely[…] -
-
-
Séminaire
-
Cryptographie
Horizontal isogeny graphs of ordinary abelian varieties and the discrete logarithm problem
Orateur : Benjamin WESOLOWSKI - École Polytechnique Federale de Lausanne
An isogeny graph is a graph whose vertices are abelian varieties (typically elliptic curves, or Jacobians of genus 2 hyperelliptic curves) and whose edges are isogenies between them. Such a graph is "horizontal" if all the abelian varieties have the same endomorphism ring. We study the connectivity and the expander properties of these graphs. We use these results, together with a recent algorithm[…] -