Table of contents

The cryptography seminar is systematically visible by videoconference.

Practical infos

  • Date

    The cryptography seminar of Rennes takes place every Friday at 1:45 p.m. Any participant can suggest a guest or a talk subject by using the form below..

  • Location

    IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes Amphi Lebesgue
    Locate on OpenStreetMaps

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Next sessions

  • Cyclotomic Cosets: Hidden Subgroup and Quantum Sieving Algorithm for Prime-Power Moduli

    • November 06, 2026 (13:45 - 14:45)

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

    Speaker : Mathias Boucher - Université de Rennes

    The Dihedral Coset Problem (DCP), also known as the hidden shift problem, plays a fundamental role in post-quantum public-key cryptography, since the Learning-With-Error problem reduces to DCP. The “Simon meets Kuperberg” quantum algorithm by Bonnetain and Naya-Plasencia solves the DCP in quasi-polynomial time when the modulus is a power of two. We provide a generalization of this algorithm for[…]

  • 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 (09:30 - 15:15)

    • Amphithéâtre E - Bâtiment 02A, Campus de Beaulieu - A map of the Beaulieu campus can be viewed at: https://www.univ-rennes.fr/en/beaulieu-campus-map (the building is south of the campus)

    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. The talks will take place at Amphi E in building 02A. To register for lunch, please do so before oct 30th using this link. 

  • Chiffrement homomorphe à l'aide des groupes après Nuida

    • November 27, 2026 (13:45 - 14:45)

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

    Speaker : Pierre Guillot - Ravel Technologies/Université de strasbourg

    Nuida et d'autres ont montré comment on peut obtenir un protocole de chiffrement pleinement homomorphe si l'on sait chiffrer les éléments d'un groupe G convenable, tout en sachant faire l'opération de G "en homomorphe".   Les exemples étaient jusqu'à présent limités au chiffrement d'un bit à la fois, avec beaucoup d'opérations à effectuer pour "simuler" les portes logiques usuelles. Je vais[…]

    • Cryptography

Previous session

Module Learning With Errors and Structured Extrapolated Dihedral Cosets

  • October 02, 2026 (13:45 - 14:45)

  • Batiment 32A salle 8

Speaker : Jinwei Zheng - Télécom Paris

The Module Learning With Errors (MLWE) problem is the fundamental hardness assumption underlying the key encapsulation and signature schemes ML-KEM and ML-DSA, which have been selected by NIST for post-quantum cryptography standardization. Understanding its quantum hardness is crucial for assessing the security of these standardized schemes.   Inspired by the equivalence between LWE and[…]

  • Cryptography

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Subscribe to the mailing list

A mailing list is available for announcements concerning Cryptography seminar's talks. To subscribe, you just have to send an email to sympa@listes.univ-rennes1.fr with subscribe math-crypto as a subject.

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Presentation of the seminar

  • Scientists welcome the renewed interest and original insight that cryptography brings to their disciplines, as well as the intellectual challenges posed to them.

    Multidisciplinary par excellence, cryptography constitutes a point of contact between number theory, algebraic geometry, algorithms and computer science. It brings whole sections of the most fundamental mathematics into contact with applications of great practical importance. 

  • Leader :

    Board :

    • The General Directorate of Armament (DGA) : state body responsible for the development of cryptographic algorithms, which depends on the the Ministry of the Armed Forces.
    • Rennes Mathematical Research Institute (IRMAR) : mathematics research laboratory associating the National Center for Scientific Research (CNRS), the University of Rennes, the École Normale Supérieure de Cachan (ENS Cachan), the National Institute of Applied Sciences of Rennes (INSA Rennes) and the University of Rennes 2.
    • Institute for Research in Computer Science and Random Systems (IRISA): computer science research laboratory in Rennes.

    DGA, IRISA and IRMAR wish, by organizing this cooperative seminar, to crystallize the interest of different actors in the Rennes region around cryptography and, beyond current fashion, to encourage fruitful and scientific collaboration. quality.

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