599 results
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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[…] -
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[…] -
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[…] -
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[…] -
Oblivious Transfer: mieux que le PIR ?
Speaker : Olivier Blazy - Limoges
La notion d'Oblivious Transfer a été introduite en 1981 par Rabin, dans le but d'autoriser un receveur à recevoir une (et seulement une) ligne dans une base de k messages, sans que l'émetteur ne sache lequel. Diverses techniques /modèles ont été proposés pour réaliser cette fonctionnalité, nous montrerons dans cet exposé de récents développements sur comment instancier génériquement[…]