Filter by content type

Select one or more filters. This choice will reload the page to display the filtered results.

Remove all filters

655 results

    • Seminar

    • Cryptography

    On weak keys in QC-MDPC schemes

    • February 21, 2020

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

    Speaker : Valentin Vasseur - INRIA

    Quasi-cyclic moderate density parity check (QC-MDPC) codes allow the design of McEliece-like public-key encryption schemes with compact keys and a security that provably reduces to hard decoding problems for quasi-cyclic codes. Because of these features, QC-MDPC have attracted a lot of interest from the cryptographic community. In particular, the BIKE suite of key exchange mechanisms has been[…]
    • Seminar

    • Cryptography

    Soutenance de thèse: Theoretical Hardness of Algebraically Structured Learning With Errors

    • November 16, 2021

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

    Speaker : Katharina Boudgoust - Rennes

    The main focus of this PhD thesis lies on the computational problem Learning With Errors (LWE). It is a core building block of lattice-based cryptography, which itself is among the most promising candidates to replace current cryptographic protocols once large-scale quantum computers may be available. The contributions of the present work are separated into two different parts. First, we study the[…]
    • Seminar

    • Cryptography

    The generalized quaternion isogeny path problem.

    • April 03, 2020

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

    Speaker : Antonin Leroux - LIX

    The correspondence between maximal orders in a quaternion algebra and supersingular elliptic curves has uncovered new perspectives in the field of isogeny-based cryptography. The KLPT algorithm of Kohel et al. in 2014 introduces an algorithm solving the quaternion isogeny path problem in polynomial time. Studying this problem has applications both constructive and destructive. It has allowed to[…]
    • Seminar

    • Cryptography

    Soutenance de thèse: Study and design of new encryption primitives based on rank metric error correcting codes

    • December 10, 2021

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

    Speaker : Ba Duc Pham - Rennes

    In 2005, Faure and Loidreau proposed a new rank-metric cryptosystem inspired from the Hamming metric scheme of Augot-Finiasz in 2003. In 2018, it was broken by the attack of Gaborit, Otmani and Kalachi. Recently, there are some attempts of repairing the Faure-Loidreau scheme, for example the work of Renner, Puchinger and Wachter–Zeh which is called LIGA. In this thesis, we also introduce a new[…]
    • Seminar

    • Cryptography

    Lattice-based signatures: from construction to implementation

    • November 29, 2019

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

    Speaker : Pauline Bert - soutenance de thèse, amphi P de l'ISTIC, 14h

    Lattice-based cryptography is one of the major line of research to build post-quantum public key primitives. In this thesis, we discuss about digital signatures constructions and their implementation. We first describe a Fiat-Shamir transformation from an identification scheme using rejection sampling to a digital signature secure in the random oracle model. Then we describe an identity-based[…]
    • Seminar

    • Cryptography

    Code-based postquantum cryptography : candidates to standardization

    • April 23, 2021

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

    Speaker : Nicolas Sendrier - INRIA

    At the third round of the NIST standardization process, three candidates remain with a security based on error correcting codes, all are key exchange mechanisms. We will explore them according to their security assumptions and properties. Among them, we find an historical scheme (Classic McEliece), as well as schemes using sparse and quasi-cyclic matrices (BIKE and HQC). We will examine pros and[…]