Table of contents

  • This session has been presented June 23, 2006.

Description

  • Speaker

    Hendrik Hubrechts - Leuven University

Let p be a small prime number, F a field of characteristic p and extension degree n, and E a hyperelliptic curve over F. In cryptography one tries to exploit the hardness of determining a discrete logarithm on the jacobian of such curves. In order to achieve this it is important to know what the size of this jacobian is. This parameter can be deduced from the zeta function of the curve.<br/> We will present algorithms to compute this zeta function for curves in one parameter families. The advantage of such `deformation' algorithms, when compared with Kedlaya's classical algorithm, is mainly a dramatically reduced memory usage, although a decrease in time requirements is attainable as well. We will also show the results of an implementation of such an algorithm.

Next sessions

  • Adelic reduction of module lattices

    • November 13, 2026 (13:45 - 14:45)

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

    Speaker : Henry Bambury - DGA-MI et Inria Rennes

    We give a strict generalisation of the LLL algorithm over number fields, based on the reduction theory of  $GL(n)$ over the adele ring of a number field. Our algorithm is free of heuristics, with rigorous bounds on output quality and complexity.   -- based on joint work with Seungki Kim, Changmin Lee and Phong Nguyen --
    • Cryptography

  • European Cyber Week: atelier cryptographie post-quantique

    • From November 18, 2026 to November 19, 2026 (09:00 - 18:00)

    • Couvent des jacobins, Rennes

    Dans la continuité des éditions 2021, 2022 et 2024, la DGA — en partenariat avec CREACH LABS et avec le soutien de l'ANSSI, de l'IRISA, de l'IRMAR et du Pôle d'Excellence Cyber — organise la 4e édition de l'atelier consacré à la cryptographie post-quantique dans le cadre de l'European Cyber Week 2026. Attention, il faut s'inscrire (gratuitement) au préalable — s'inscrire à la conférence Les[…]
  • Post-quantum day of the cryptography seminar

    • November 20, 2026 (09:00 - 15:00)

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

    A scientific day devoted to post-quantum cryptography, held in the wake of the European Cyber Week, with talks more technical than those presented at the ECW.
Show previous sessions