Je recherche

644 résultats

• • Séminaire

  • Cryptographie

  identity-based encryption with rank metric

  • 15 septembre 2017

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

  Orateur : Adrien Hauteville - Université de Limoges

  Code-based cryptography has a long history, almost as long as the history of public-key encryption (PKE). While we can construct almost all primitives from codes such as PKE, signature, group signature etc, it is a long standing open problem to construct an identity-based encryption from codes. We solve this problem by relying on codes with rank metric. The concept of identity-based encryption […]

• • Séminaire

  • Cryptographie

  Improved Cryptanalysis of Rank Metric Schemes Based on Gabidulin Codes.

  • 03 février 2017

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

  Orateur : Hervé Talé Kalachi - Université de Rouen et Université de Yaoundé, Cameroun

  In this presentation, we prove that any variant of the GPT cryptosystem which uses a right column scrambler over the extension field as advocated by the works of Gabidulin et al. with the goal to resist to Overbeck’s structural attack are actually still vulnerable to that attack. We show that by applying the Frobenius operator appropriately on the public key, it is possible to build a Gabidulin[…]

• • Séminaire

  • Cryptographie

  CRYSTALS: Dilithium and Kyber

  • 10 novembre 2017

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

  Orateur : Damien Stehlé - ENS de Lyon

  Kyber -- a Key Exchange Mechanism -- and Dilithium -- a digital signature -- are the two components of the Cryptographic Suite for Algebraic Lattices (CRYSTALS). I will present the intractable problems underlying their security, overview their design and comment their practical performance. The talk is based on the following articles:<br/> https://eprint.iacr.org/2017/633.pdf<br/&gt; https:/[…]

• • Séminaire

  • Cryptographie

  A Modular Security Analysis of EAP and IEEE 802.11

  • 07 avril 2017

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

  Orateur : Haakon Jacobsen - TBD

  The Extensible Authentication Protocol (EAP) is a widely used three-party authentication framework that allows a client to connect to a wireless access point it does not share a secret with, using a mutually trusted server. EAP is often found in enterprise networks or large organizations to provide central key-management and user authentication; one prime example being the eduroam network.<br/> In[…]

• • Séminaire

  • Cryptographie

  On the Construction of Lightweight S-Boxes

  • 15 décembre 2017

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

  Orateur : Sébastien Duval - INRIA Paris-Rocquencourt

  S-Boxes are essential objects in the conception of blockciphers. Typically, an S-Box is simply a permutation (bijective function) on n bits, with n small (usually 4 or 8). Its role in a blockcipher is to bring nonlinearity to the cipher, thus an S-Box must be highly nonlinear. Several parameters of a function are used to measure nonlinearity, among which the most important are differential[…]

• • Séminaire

  • Cryptographie

  Design de cryptographie white-box : n'oublions pas la grey-box

  • 02 décembre 2016

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

  Orateur : Philippe Teuwen - QuarksLab

  Bien que toutes les tentatives académiques actuelles pour créer des primitives cryptographiques standard en white-box aient été cassées, il y a encore un grand nombre d'entreprises qui vendent des solutions "sécurisées" de cryptographie white-box. Afin d'évaluer le niveau de sécurité de solutions en boîte blanche, nous verrons de nouvelles approches qui ne nécessitent ni connaissance des tables[…]