Table of contents

  • This session has been presented March 29, 2002.

Description

  • Speaker

    Pierrick Gaudry - Lix Ecole Polytechnique

Nous commencerons par rappeler les méthodes algorithmiques pour manipuler les courbes hyperelliptiques, et en particulier l'attaque du problème du logarithme discret par des méthodes de calcul d'index. Nous présenterons ensuite la méthode de la restriction de Weil, dont Frey fut le premier a soupçonner les conséquences cryptographiques. En traçant une courbe hyperelliptique sur la restriction de Weil d'une courbe elliptique, on peut dans certains cas obtenir un algorithme de logarithme discret plus rapide que les meilleurs connus précédemment, remettant en cause la sécurité des cryptosystèmes correspondants.

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