Table of contents

  • This session has been presented October 22, 2021.

Description

  • Speaker

    Maxime Bombar - Ecole Polytechnique

Error correcting codes are well known to provide possible candidates for building quantum safe cryptographic primitives. Besides the Hamming metric which has a long-standing history, one may consider other metrics such as the rank metric. Gabidulin codes are the rank metric analogue of Reed-Solomon codes and can be efficiently decoded up to half the minimum distance. However, beyond this radius, they are believed to be difficult to decode. Based on this hard problem, in 2005 Faure and Loidreau designed an encryption scheme with small public keys. In 2016 though, this scheme was subject to a very efficient key recovery attack by Gaborit, Otmani and Talé-Kalachi. More recently, two independent repairs of Faure-Loidreau scheme resisting the previous attack appeared. The first one, due to Renner, Puchinger and Wachter-Zeh is called LIGA, and the second one due to Lavauzelle, Loidreau and Pham is called RAMESSES. In this talk, I will present how to decode any code extending the Gabidulin codes, at the cost of a significant decrease of the decoding radius, and show how this decoder can be used to provide an efficient message recovery attack on LIGA and RAMESSES.<br/> This is joint work with Alain Couvreur.<br/> lien: https://univ-rennes1-fr.zoom.us/j/97066341266?pwd=RUthOFV5cm1uT0ZCQVh6QUcrb1drQT09

Next sessions

  • Verification of Rust Cryptographic Implementations with Aeneas

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

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

    Speaker : Aymeric Fromherz - Inria

    From secure communications to online banking, cryptography is the cornerstone of most modern secure applications. Unfortunately, cryptographic design and implementation is notoriously error-prone, with a long history of design flaws, implementation bugs, and high-profile attacks. To address this issue, several projects proposed the use of formal verification techniques to statically ensure the[…]

  • On the average hardness of SIVP for module lattices of fixed rank

    • March 06, 2026 (13:45 - 14:45)

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

    Speaker : Radu Toma - Sorbonne Université

    In joint work with Koen de Boer, Aurel Page, and Benjamin Wesolowski, we study the hardness of the approximate Shortest Independent Vectors Problem (SIVP) for random module lattices. We use here a natural notion of randomness as defined originally by Siegel through Haar measures. By proving a reduction, we show it is essentially as hard as the problem for arbitrary instances. While this was[…]

  • Journées C2: pas de séminaire

    • April 03, 2026 (13:45 - 14:45)

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

  • Endomorphisms via Splittings

    • April 10, 2026 (13:45 - 14:45)

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

    Speaker : Min-Yi Shen - No Affiliation

    One of the fundamental hardness assumptions underlying isogeny-based cryptography is the problem of finding a non-trivial endomorphism of a given supersingular elliptic curve. In this talk, we show that the problem is related to the problem of finding a splitting of a principally polarised superspecial abelian surface. In particular, we provide formal security reductions and a proof-of-concept[…]

    • Cryptography

Show previous sessions
Page top