687 résultats

• • Séminaire

  • Cryptographie

  Elliptic curves for SNARKs

  • 01 septembre 2022

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

  Orateur : Youssef El Housni - LIX

  At CANS’20, El Housni and Guillevic introduced a new 2-chain of pairing-friendly elliptic curves for recursive zero-knowledge Succinct Non-interactive ARguments of Knowledge (zk-SNARKs) made of the former BLS12-377 curve (a Barreto–Lynn–Scott curve over a 377- bit prime field) and the new BW6-761 curve (a Brezing–Weng curve of embedding degree 6 over a 761-bit prime field). First we generalise the[…]

• • Séminaire

  • Cryptographie

  New Representations of the AES Key Schedule

  • 10 juin 2022

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

  Orateur : Clara Pernot - INRIA Paris

  In this talk we present a new representation of the AES key schedule, with some implications to the security of AES-based schemes. In particular, we show that the AES-128 key schedule can be split into four independent parallel computations operating on 32 bits chunks, up to linear transformation. Surprisingly, this property has not been described in the literature after more than 20 years of[…]

• • Séminaire

  • Cryptographie

  Fault tolerant algorithms via decoding: Interleaving techniques

  • 17 juin 2022

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

  Orateur : Eleonora Guerrini - Université Montpellier

  Evaluation Interpolation algorithms are a key tool for the algebraic decoding of a large class of codes, including the famous Reed Solomon codes. Recent techniques allow the use of this type of decoding in the more general setting of fault tolerant algorithms, where one has to interpolate erroneous data (potentially computed by an untrusted entity). In this talk we will present algorithms to[…]

• • Séminaire

  • Cryptographie

  Cryptanalysis of code-based cryptosystems using the square-code distinguisher

  • 07 février 2020

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

  Orateur : Mathieu Lequesne - INRIA

  Many code-based cryptosystems have been proposed recently, especially in response to the call for post-quantum cryptography standardization issued by the National Institute of Standards and Technologie. Most code-based cryptosystem rely on the same idea: an error-correcting code with some special structural properties (including good error-correction capacity) serves as the private key. This code[…]

• • Séminaire

  • Cryptographie

  Decoding Supercodes of Gabidulin Codes and Applications to Cryptanalysis

  • 22 octobre 2021

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

  Orateur : 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,[…]

• • Séminaire

  • Cryptographie

  Cryptographie post-quantique fondée sur les codes : les candidats à la standardisation

  • 25 mars 2020

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

  Orateur : Nicolas Sendrier - INRIA

  Au second tour du processus de standardisation du NIST, il reste 7 candidats dont la sécurité est fondée sur les code correcteurs, tous sont des mécanismes d'échange de clé. Nous les classifierons selon leurs hypothèses de sécurité et leurs propriétés. Nous trouvons les systèmes « historiques » (Classic McEliece et NTS-KEM), les systèmes fondés sur des matrices creuses et quasi-cycliques (BIKE,[…]