544 results

  • Towards Non-Interactive Zero-Knowledge from CDH and LWE

    • January 18, 2019

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

    Speaker : Geoffroy Couteau - Karlsruher Institut für Technologie (KIT)

    We provide a generic construction of non-interactive zero-knowledge (NIZK) schemes. Our construction is a refinement of Dwork and Naor’s (FOCS 2000) implementation of the hidden bits model using verifiable pseudorandom generators (VPRGs). Our refinement simplifies their construction and relaxes the necessary assumptions considerably. As a result of this conceptual improvement, we obtain[…]
  • Wave: A New Code-Based Signature Scheme

    • January 11, 2019

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

    Speaker : Thomas Debris-alazard - inria

    It is a long standing open problem to build an efficient and secure digital signature scheme based on the hardness of decoding a linear code which could compete with widespread schemes like DSA or RSA. The latter signature schemes are broken by a quantum computer with Shor’s algorithm. Code-based schemes could provide a valid quantum resistant replacement. We present here Wave the first « hash[…]
  • Some new results on cube attacks against Trivium

    • December 14, 2018

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

    Speaker : Tian Tian - Université de Zhengzhou

    Trivium is a bit oriented synchronous stream cipher designed by Cannière and Preneel. It is one of the eSTREAM hardware-oriented finalists and an International Standard under ISO/IEC 29192-3:2012. Cube attacks are an important type of key recovery attack against Trivium. First, I will give a survey on cube attacks against Trivium. Second, I will present our recent results including an algebraic[…]
  • Soutenance de thèse (exceptionnellement jeudi à 14h): Couches de diffusion linéaires à partir de matrices MDS

    • December 13, 2018

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

    Speaker : Victor Cauchois - DGA/Université Rennes 1

    Cette thèse s’intéresse à deux aspects de la cryptologie symétrique liés à l’utilisation de matrices MDS dans les couches de diffusion linéaires de primitives. Une première partie se fonde sur les conceptions de couches de diffusion linéaires de schémas de chiffrement symétrique à partir de matrices MDS. Les associations entre matrices récursives, respectivement circulantes, et polynômes sont[…]
  • Aggregate Cash Systems: A Cryptographic Investigation of Mimblewimble

    • November 30, 2018

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

    Speaker : Michele Orru - ENS

  • Repairing the Faure-Loidreau Public-Key Cryptosystem

    • November 23, 2018

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

    Speaker : julian renns - Teschnische Universität Munchen

    A repair of the Faure–Loidreau (FL) public-key code-based cryptosystem is proposed. The FL cryptosystem is based on the hardness of list decoding Gabidulin codes which are special rank-metric codes. We prove that the recent structural attack on the system by Gaborit et al. is equivalent to decoding an interleaved Gabidulin code. Since all known polynomial-time decoders for these codes fail for a[…]