Table of contents

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 sending an email to one of the scientific committee members.
  • Location

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

  • Efficient zero-knowledge proofs and arguments in the CL framework

    • March 07, 2025 (13:45 - 14:45)

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

    Speaker : Agathe Beaugrand - Institut de Mathématiques de Bordeaux

    The CL encryption scheme, proposed in 2015 by Castagnos and Laguillaumie, is a linearly homomorphic encryption scheme, based on class groups of imaginary quadratic fields. The specificity of these groups is that their order is hard to compute, which means it can be considered unknown. This particularity, while being key in the security of the scheme, brings technical challenges in working with CL,[…]
  • Constant-time lattice reduction for SQIsign

    • March 14, 2025 (13:45 - 14:45)

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

    Speaker : Sina Schaeffler

    SQIsign is an isogeny-based signature scheme which has recently advanced to round 2 of NIST's call for additional post-quantum signatures. A central operation in SQIsign is lattice reduction of special full-rank lattices in dimension 4. As these input lattices are secret, this computation must be protected against side-channel attacks. However, known lattice reduction algorithms like the famous[…]
  • Circuit optimisation problems in the context of homomorphic encryption

    • March 21, 2025 (13:45 - 14:45)

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

    Speaker : Sergiu Carpov - Arcium

    Fully homomorphic encryption (FHE) is an encryption scheme that enables the direct execution of arbitrary computations on encrypted data. The first generation of FHE schemes began with Gentry's groundbreaking work in 2019. It relies on a technique called bootstrapping, which reduces noise in FHE ciphertexts. This construction theoretically enables the execution of any arithmetic circuit, but[…]
  • Journées C2

    • April 04, 2025 (00:00 - 18:00)

    • Pornichet

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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.