527 résultats
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Cryptographie post-quantique fondée sur les codes : les candidats à la standardisation
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,[…] -
Implicit proofs of membership
Orateur : 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 show how[…] -
Improved Classical and Quantum Algorithms for Subset-Sum
Orateur : 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
Orateur : 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[…] -
Cryptanalysis of code-based cryptosystems using the square-code distinguisher
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[…] -
Constant time techniques for lattice based cryptography
Orateur : Melissa Rossi - École normale supérieure, CNRS, PSL University, Inria
NIST’s post-quantum cryptography competition has entered in its second phase, the time has come to focus more closely on practical aspects of the candidates. On the lattice-based side, certain schemes chose to implement discrete Gaussian distributions which allow better parameters and security reductions. However, this advantage has also proved to be their Achilles’ heel, as discrete Gaussians[…]