511 results
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The generalized quaternion isogeny path problem.
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[…] -
Cryptographie post-quantique fondée sur les codes : les candidats à la standardisation
Speaker : 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 […] -
Candidats NIST basés sur les réseaux: choix de conception et astuces de ninja
Speaker : Thomas Prest. - PQShield
Parmi les 26 schémas post-quantique toujours considérés pour standardisation par le NIST, 12 sont basés sur les réseaux (3 schémas de signature et 9 schémas de chiffrement). Cette présentation leur est consacrée. A haut niveau, tous peuvent être interprétés comme des instanciations directes de paradigmes bien établis. Mais une analyse plus attentive révèle que chacun d'eux fait des choix de[…] -
Implicit proofs of membership
Speaker : Olivier Blazy - Université Limoges
Smooth hash proof systems have been introduced by Cramer and shoup to build compact efficient cca2 encryption in the standard model. Since then, they found applications in a broad range of protocols from oblivious transfer to authenticated key exchange, passing by witness examples.<br/> In this talk, we will start by a panorama of languages that can be managed by such a primitive and then[…] -
Improved Classical and Quantum Algorithms for Subset-Sum
Speaker : André Schrottenloher - INRIA
We present new classical and quantum algorithms for solving random hard instances of the subset-sum problem, in which we are given n integers on n bits and try to find a subset of them that sums to a given target. This classical NP-complete problem has several applications in cryptography and underlies the security of some proposed post-quantum cryptosystems.<br/> At EUROCRYPT 2010, Howgrave[…] -
On weak keys in QC-MDPC schemes
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[…]