627 results

  • Subject Access Request and Proof of Ownership

    • October 25, 2019

    • Inria Center of the University of Rennes - - Petri/Turing room

    Speaker : Cédric Lauradoux (INRIA Rhône-Alpes)

    The GDPR (General Data Protection Regulation) provides rights on our data: access, rectification, objection, etc. However, this regulation is not binding on how we can exercise these rights. Data controllers have therefore deployed various methods to authenticate subject requests. We have analyzed how this authentication process can fail and examined its consequences. Our study shows that a key[…]
  • Post-quantum cryptography based on supersingular isogeny problems?

    • October 25, 2019

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

    Speaker : Christophe Petit - University of Birmingham

    The security of many cryptographic protocols in use today relies on the computational hardness of mathematical problems such as integer factorization. These problems can be solved using quantum computers, and therefore most of our security infrastructures will become completely insecure once quantum computers are built. Post-quantum cryptography aims at developing security protocols that will[…]
  • Optimisation des Principaux Composants des Chiffrements par Bloc

    • October 22, 2019

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

    Speaker : Baptiste Lambin - soutenance de thèse salle Métivier à l'IRISA, 14h

    La sécurité des chiffrements par bloc évolue constamment au fur et à mesure que de nouvelles techniques de cryptanalyse sont découvertes. Lors de la conception de nouveaux chiffrements par bloc, il est donc nécessaire de considérer ces nouvelles techniques dans l'analyse de sécurité. Dans cette thèse, nous montrons comment construire certaines opérations internes des chiffrements par bloc pour[…]
  • Isogeny-based cryptography from superspecial genus-2 curves

    • October 18, 2019

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

    Speaker : Wouter Castryck - KU Leuven

    I will report on some first attempts to do isogeny-based cryptography in genus 2. More precisely, we will use isogeny graphs of superspecial principally polarized abelian surfaces over GF(p^2) for constructing variants of Charles, Goren and Lauter's hash function and of Jao and De Feo's SIDH key exchange protocol, both of which use supersingular elliptic curves over GF(p^2). This will be largely[…]
  • Lossy trapdoor primitives, zero-knowledge proofs and applications

    • October 04, 2019

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

    Speaker : Chen Qian - soutenance de thèse salle Métivier à l'IRISA, 14h

    In this thesis, we study two differentprimitives. Lossy trapdoor functions and zero-knwoledge proof systems.The lossy trapdoor functions (LTFs) arefunction families in which injective functionsand lossy ones are computationally indistin-guishable. Since their introduction, they havebeen found useful in constructing various cryp-tographic primitives. We give in this thesisefficient constructions of[…]
  • Supersingular isogeny Diffie-Hellman

    • October 04, 2019

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

    Speaker : Leonardo Colo - Univesité Aix-Marseille

    Supersingular isogeny graphs have been used in the Charles–Goren–Lauter cryptographic hash function and the supersingular isogeny Diffie–Hellman (SIDH) protocole of De\,Feo and Jao. A recently proposed alternative to SIDH is the commutative supersingular isogeny Diffie–Hellman (CSIDH) protocole, in which the isogeny graph is first restricted to $\FF_p$-rational curves $E$ and $\FF_p$-rational[…]