Posts classified under: Séminaire Cryptologie et sécurité

Dans la recherche actuelle de primitives pouvant résister à l'utilisation d'un ordinateur quantique, une des pistes majeure se base sur les réseaux euclidiens, et en particulier sur le problème Learning With Errors (LWE). En effet, il existe une réduction pire cas -- moyen cas vers le problème classique de réseaux qu'est le Shortest Vector Problem … Continue reading Andrea Lesavourey – Vecteurs courts dans des réseaux idéaux ; études pratiques.

Syndrome decoding problem is one of the central problems in coding theory as well as in code-based cryptography. The problem is known to be NP-complete and, for conveniently chosen parameters, exponentially hard for both classical and quantum algorithms. As such, it is proposed as a basis of classical protocols resistant to quantum attacks, i.e., post-quantum … Continue reading Simona Etinski – Generic Syndrome Decoding Problem and its Application to Cryptography

On étudie dans cette présentation l’uniformité différentielle des polynômes de degré pair définis sur des corps finis de caractéristique 2. Une caractérisation des polynômes Morse permet de comparer certains groupes de monodromie arithmétiques et géométriques et ainsi d’appliquer le théorème de densité de Chebotarev, central dans notre travail. On en déduit que pour certains degrés … Continue reading Ali Issa – Sur l’uniformité différentielle des polynômes sur les corps finis de caractéristique paire

In December 2019 were announced two new record computations: the factorization of RSA-240 (240 digits, 795 bits) and discrete logarithm computation in a prime field of the same size, with the same software, running on the same platforms. This is the first time that integer factorization (IF) and discrete logarithm (DL) of the same size … Continue reading Aurore Guillevic – Factoring RSA of 240 decimal digits and computing discrete logarithms in a 240-decimal-digit prime field with the same software and hardware.

Parmi toutes les possibilités de constructions post-quantiques, mises en avant par la compétition de standardisation post-quantique organisée par le NIST, la cryptographie reposant sur les réseaux euclidiens est la plus prometteuse. En effet, trois des quatre premiers standard proposés par le NIST reposent sur des hypothèses de réseaux. Dans cet exposé, je vais tout d'abord … Continue reading Adeline Roux-Langlois – Difficulté du problème « Module Learning with Errors »

In this talk, we will give a broad introduction of the Tezos blockchain by introducing its architecture and design choices regarding safety and security in an adversarial distributed system. We will then present Tezos smart-contract language: Michelson, a statically typed stacked-based (domain-specific) language. Lastly, we will talk an ongoing work aiming to develop a static … Continue reading Vincent Botbol – Introduction to the Tezos blockchain and static analysis of smart-contracts

In this talk, I will introduce FPPW, a new payment channel with watchtower scheme for Bitcoin. This new scheme provides fairness with respect to all channel participants including both channel parties and the watchtower. The watchtower in FPPW learns no information about the off-chain transactions and hence the channel balance privacy is preserved. As a … Continue reading Amin Sakzad – FPPW: A Fair and Privacy-Preserving Watchtower For Bitcoin

In this seminar, I will discuss some of our contributions centered around deep learning, specifically addressing two computer vision tasks. The first task will be on semantic image segmentation, a task aiming to assign a category label to each pixel in input images. While deep learning methods have demonstrated impressive performance in semantic segmentation, their … Continue reading Ayoub Karine – Beyond Pixels and 3D point Clouds: Exploring Deep Learning for Semantic Image Segmentation and 3D Point Cloud Quality Assessment

Euclidean lattices are among the most promising objects for building a post-quantum cryptography, i.e. constructions that would resist the power of large scale quantum computers. For efficiency reasons, most constructions use lattices enjoying a strong algebraic structure, and can be interpreted as constructions over polynomials with rational coefficients. However, it is still unknown to this … Continue reading Andrea Lesavourey – Diagonally dominant matrices in cryptography