624 results
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Certification de représentations galoisiennes modulaires
Speaker : Nicolas Mascot - Université de Bordeaux 1
Nous verrons comment certifier algorithmiquement des calculs de représentations galoisiennes associés à des formes modulaires, en nous appuyant notamment sur le théorème de Khare-Wintenberger (ex conjecture de modularité de Serre) et des calculs de cohomologie des groupes afin de déterminer le groupe de Galois de certains polynômes. -
Soutenance de thèse
Speaker : Gwezheneg Robert - Rennes 1
Le codage espace-temps désigne les codes correcteurs mis en place pour les transmissions MIMO. (Ce sont des transmissions sans fil utilisant plusieurs antennes, en émission comme en réception.) Ces codes correcteurs ont la particularité d'avoir des coefficients dans le corps des complexes, et non dans des corps finis. Un des paramètres fondamentaux pour l'évaluation des performances des codes[…] -
Algebraic Decoding of Folded Gabidulin Codes
Speaker : Hannes Bartz - Technische Universität München
Folded Gabidulin codes were proposed by Mahdavifar and Vardy in 2012. Beside the code construction an interpolation-based decoding scheme that can correct rank errors beyond the unique decoding radius for low code rates was presented.<br/> In this talk we present an efficient interpolation-based decoding algorithm for folded Gabidulin codes that can correct rank errors beyond half the minimum rank[…] -
Simplified Settings for Discrete Logarithms in Small Characteristic Finite Fields
Speaker : Cécile Pierrot - UPMC LIP6
Public key cryptography is based on hard problems, such as the discrete logarithm problem (DLP). In this talk, I focus on the discrete logarithm problem in finite fields:<br/> Given GF(q^k) and a generator g of GF(q^k)*, we say that we solve the DLP in GF(q^k) if, for any arbitrary element h in GF(q^k)*, we are able to recover an integer x such that: g^x = h. When the characteristic is small[…] -
Computing individual discrete logarithms in non-prime finite fields
Speaker : Aurore Guillevic - Inria Saclay, équipe Grace et Ecole Polytechnique, LIX
This talk is about computing discrete logarithms in non-prime finite fields. These fields arise in pairing-based cryptography. In this setting, the pairing-friendly curve is defined over GF(q) and the pairing takes its values in an extension GF(q^k), where k is the embedding degree.<br/> Fr example, GF(p^2) is the embedding field of supersingular elliptic curves in large characteristic; GF(p^3),[…] -
Cryptography, Encryption, and Big Data
Speaker : Hoeteck Wee - ENS
We live in an era of "Big Data", wherein a deluge of data is being generated, collected, and stored all around us. In order to protect this data, we need to encrypt it. This raises a fundamentally new challenge in cryptography: Can we encrypt data while enabling fine-grained access control and selective computation, as is necessary to protect big, complex data? In this talk, I will present my work[…]