Cognitive Approach to e-Learning in Sciences and Technologies

This article describes the approach adopted and the results obtained by the international team developing WBLST (Web Based Learning in Sciences and Technologies) a Web-based application for e-learning, developed for the students of “UVPL: Université Virtuelle des Pays de la Loire”. The developed e-learning system covers three levels of learning activities - content, exercises, and laboratory. The delivery model is designed to operate with domain concepts as relevant providers of semantic links. The aim is to facilitate the overview and to help the establishment of a mental map of the learning material. The implemented system is strongly based on the organization of the instruction in virtual classes. The obtained quality of the system is evaluated on the bases of feedback form students and professors

Caractérisation statistique de signaux de type ROS polarimétriques. Application au codage avec compression d'information

L'obtention d'images satellitaires de type radar nécessite la transmission d'une quantité très importante de données, car le traitement de construction des images ne peut généralement pas être effectué directement à bord. Un traitement de compression des données acquises est donc requis. Les résolutions actuelles des images ne permettent pas de réaliser des codages sans perte d'une partie de l'information. Les propriétés statistiques du signal sont en outre généralement négligées. Or, la corrélation intrinsèque de ces signaux peut être exploitée afin d'augmenter les performances des procédés de compression. Le but de cet article consiste à montrer des exemples de techniques de compression et l'apport de la prise en compte des propriétés statistiques en vue de la compression de signaux effectivement mesurés

Fragile Watermarking using Chaotic Sequences *

Abstract I

Chaos-based Cryptography: a Promising Technology

Journée GDR ISIS "Traitement et communication des images médicales" Université d’Evry Val d’Essonne, 23 mars 2017Security and confidentiality of image and video data is an important research topic and have been widely investigated by using standard cryptography and chaos-based cryptography. Indeed, a variety of chaos-based cryptosystems have been investigated during the last decade. Most of them are based on the structure of Fridrich, which is based on the traditional confusion-diffusion architecture proposed by Shannon. Compared with traditional cryptography, the chaos-based cryptography are more flexible which make them more suitable for large scale-data encryption, such as images and video. The heart of any chaos-based cryptosystem is the chaotic generator and so, a part of the efficiency (robustness, speed) of the system depends greatly on it. Furthermore, in stream ciphers all the security depend on the used pseudo-random number generator (PRNG).In this talk, we present two strong chaos-based cryptosystems: a stream cipher and block cipher. These chaos- cryptosystems are recently published

Chaos-based- Information Hiding and Security: an emergent technology

International audienceSecurity and confidentiality of image and video data is an important research topic and have been widely investigated by using standard cryptography and chaos-based cryptography. Indeed, a variety of chaos-based cryptosystems have been investigated during the last decade. Most of them are based on the structure of Fridrich, which is based on the traditional confusion-diffusion architecture proposed by Shannon. Compared with traditional cryptography, the chaos-based cryptography are more flexible which make them more suitable for large scale-data encryption, such as images and video. The heart of any chaos-based cryptosystem is the chaotic generator and so, a part of the efficiency (robustness, speed) of the system depends greatly on it. Furthermore, in stream ciphers all the security depend on the used pseudo-random number generator (PRNG).In this talk, first, we describe three of our chaos-based cryptosystems: two blocks ciphers and one selective stream cipher for HEVC coder at CABAC level. Then, we describe the structure of the proposed generator of discrete chaotic samples and we compare its performance (robustness, speed) with the traditional pseudo-random number generators used in standard cryptography (eStream)

Chaos-based Confidentiality : Chaotic generators, and Chaos-based-Cryptosystems

International audienceThe security of image and video data has become increasingly important for many applications which demand both real-time performance and high level of security: private multimedia messages exchanged by portable devices over the wireless networks and sensitive data exchanged in wireless sensor networks, etc.A new class of pseudo-random number generators (PRNGs) called chaotic PRNGs has appeared in the literature and has attracted much attention. Indeed, their characteristics such as ergodicity, sensitivity to the secret key and ease of implementation, make them very good candidates for use in information hiding and security systems such as: Keys generation, cryptosystems, steganography and watermarking systems or any system that needs random number.Due, to their structures, which are more flexible whatever the block size and more robust against cryptanalysis, a variety of chaos-based cryptosystems has been introduced to protect the content of the transmitted images and videos.In this talk, we give an overview of the state of the art of chaotic PRNGs and chaos-based cryptosystems and we describe some of our schemes already proposed

Etude theorique et experimentale de l'immunite aux perturbations electromagnetiques de cables coaxiaux et bifilaires blindes

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Chaos-based- Information Hiding and Security: an emergent technology

International audienceSecurity and confidentiality of image and video data is an important research topic and have been widely investigated by using standard cryptography and chaos-based cryptography. Indeed, a variety of chaos-based cryptosystems have been investigated during the last decade. Most of them are based on the structure of Fridrich, which is based on the traditional confusion-diffusion architecture proposed by Shannon. Compared with traditional cryptography, the chaos-based cryptography are more flexible which make them more suitable for large scale-data encryption, such as images and video. The heart of any chaos-based cryptosystem is the chaotic generator and so, a part of the efficiency (robustness, speed) of the system depends greatly on it. Furthermore, in stream ciphers all the security depend on the used pseudo-random number generator (PRNG).In this talk, first, we describe three of our chaos-based cryptosystems: two blocks ciphers and one selective stream cipher for HEVC coder at CABAC level. Then, we describe the structure of the proposed generator of discrete chaotic samples and we compare its performance (robustness, speed) with the traditional pseudo-random number generators used in standard cryptography (eStream)