Appariement de points caractéristiques trouvés à même les régions d'avant-plan de vidéos à spectres visible et infrarouge

Systèmes de caméras calibrés -- Extraction des points caractéristiques -- Appariement des points caractéristiques -- Filtrage des paires de points caractéristiques -- Filtrage des paires de points caractéristiques -- Le projet de référence -- Aperçu de la méthode -- Prétraitements -- La méthode du squelette -- Le processus DCE -- Filtrage par paires de blobs -- Filtrage par RANSAC -- Calcul des disparités -- Complexité des méthodes

RECTGAUSS-Tex : block-based background subtraction

This paper presents an approach to background subtraction based on rectangular regions (blocks). The general principle is to successively divide the image into blocks and detect foreground pixels based on the color histogram and the variance between pixels of the blocks. Then, the classic Gaussian Mixture background subtraction method is applied to refine the detected foreground. Results show that this approach reduces false positives by filtering noise coming from small motion as it is based on groups of pixels instead of on individual pixels

Isolated virtualised clusters: testbeds for high-risk security experimentation and training

International audienceAdequate testbeds for conducting security experiments and test under controlled, safe, repeatable and asrealistic- as-possible conditions, are a key element for the research and development of adequate security solutions and the training of security personnel and researchers. In this paper, we report on the construction and operations of isolated virtualised testbeds used in two separate security research labs in Canada and France, as part of a joint collaborative effort. The main idea was to use mid- to large-scale isolated computing clusters to obtain high levels of scale, manageability and safety by heavily leveraging virtualisation technology, open-source cluster management tools and a network architecture separating experiment and control traffic. Both facilities have been used for conducting different types of security research experiments, including in-lab reconstructions of botnets, denial-of-service attacks, and virus detection experimentation. They have also been used for teaching and training students in experimental security methods. We describe these facilities and the criteria that we used to design them, the research and training activities that were conducted, and close by discussing the lessons learned and the pros and cons of this approach

The case for in-the-lab botnet experimentation: creating and taking down a 3000-node botnet

International audienceBotnets constitute a serious security problem. A lot of effort has been invested towards understanding them better, while developing and learning how to deploy effective counter-measures against them. Their study via various analysis, modelling and experimental methods are integral parts of the development cycle of any such botnet mitigation schemes. It also constitutes a vital part of the process of understanding present threats and predicting future ones. Currently, the most popular of these techniques are “in-the-wild” botnet studies, where researchers interact directly with real-world botnets. This approach is less than ideal, for many reasons that we discuss in this paper, including scientific validity, ethical and legal issues. Consequently, we present an alternative approach employing “in the lab” experiments involving at-scale emulated botnets. We discuss the advantages of such an approach over reverse engineering, analytical modelling, simulation and in-the-wild studies. Moreover, we discuss the requirements that facilities supporting them must have. We then describe an experiment in which we emulated a close to 3000-node, fully-featured version of the Waledac botnet, complete with a reproduced command and control (C&C) infrastructure. By observing the load characteristics and yield (rate of spamming) of such a botnet, we can draw interesting conclusions about its real-world operations and design decisions made by its creators. Furthermore, we conducted experiments where we launched sybil attacks against the botnet. We were able to verify that such an attack is, in the case of Waledac, viable. However, we were able to determine that mounting such an attack is not so simple: high resource consumption can cause havoc and partially neutralise the attack. Finally, we were able to repeat the attack with varying parameters, in an attempt to optimise it. The merits of this experimental approach is underlined by the fact that it is very difficult to obtain these results by employing other methods

ComputeCanada/magic_castle: Magic Castle 13.1.0

<h2>Changed</h2> <ul> <li>[cloudflare] SSHFP fingerprints are now uppercase.</li> </ul> <p>Refer to <a href="https://github.com/ComputeCanada/puppet-magic_castle/blob/main/CHANGELOG.md">puppet-magic_castle changelog</a> for details on change to the Puppet environment.</p&gt

ComputeCanada/magic_castle: Magic Castle 12.6.1

No changes to infrastructure code. Refer to puppet-magic_castle changelo