HAL Portal IOGS (nstitut d'Optique Graduate School)
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Full Key-Recovery Cubic-Time Template Attack on Classic McEliece Decapsulation
No full textInternational audienceClassic McEliece is one of the three code-based candidates in the fourth round of the NIST post-quantum cryptography standardization process in the Key Encapsulation Mechanism category. As such, its decapsulation algorithm is used to recover the session key associated with a ciphertext using the private key. In this article, we propose a new side-channel attack on the syndrome computation in the decapsulation algorithm that recovers the private key, which consists of the private Goppa polynomial g and the permuted support L. The attack relies on both practical aspects and theoretical contributions, namely that the side-channel distinguisher can accurately discriminate elements of the permuted support L, while relying only on a standard noisy Hamming weight leakage assumption and that there exists a cubic-time algorithm that uses this information to recover the private Goppa polynomial g. Compared with previous work targeting the Classic McEliece private key, this drastically improves both on the assumptions made in the attacker model and on the overall efficiency of the key-recovery algorithm. We have carried out the attack in practice on a microcontroller target running the reference implementation of Classic McEliece, and make the full attack source code available
Photosensitive oxide glass for direct 3D writing of integrated photonic components
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Practical Second-Order CPA Attack on Ascon with Proper Selection Function
No full textInternational audienceAscon has recently been selected by the National Institute of Standards and Technology (NIST) as the lightweight cryptography standard. Consequently, it is utilized in a multitude of environments and devices. In this study, we examine the potential vulnerability of Ascon software implementations to Correlation Power Analysis (CPA) attacks. First, we conduct a comprehensive analysis of different approaches from the literature for choosing the selection function used to compute intermediate values in a CPA attack. Through both theoretical explanation and experimental validation, we demonstrate how these choices influence the success of the attack. Second, leveraging insights from our analysis, we present, to the best of our knowledge, the first successful and practical second-order CPA attack on a masked software implementation provided by the Ascon team running on a 32-bit microcontroller. Our results show that the full 128-bit key can be recovered in 4.7 hours through the analysis of 360,000 traces on classical laptop
Activated Diffusion of 1D J-Aggregates in Boron Nitride Nanotubes by Curvature Patterning
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Image quality metrics for restricted gamut images produced by laser-induced printing on plasmonic films
No full textInternational audienceLaser-induced printing is a low-cost, high-speed, non-contact method of marking large, highresolution images. Implemented on thin films containing metallic nanoparticles, the technique allows for the printing of color images with visual effects. However, these images typically have a limited color gamut compared to inkjet printing. This limitation is due to the inability to achieve high levels of saturation for all colors and to cover the sRGB hue range. While common quality metrics focus primarily on aspects such as resolution or blur, they rarely address the color aspect. This study proposes a methodology to provide image quality metrics adapted to color gamuts with unusual shapes and volumes. It aims to rank them in terms of image quality performance for any given image. In particular, this work focuses on gamuts measured in transmission and reflection that are not necessarily centered on the CIE a*b* plane and may exhibit low contrast. Psychophysical studies have been conducted to evaluate the quality of images simulated with different color gamuts. The same images were evaluated using different metrics, and an analysis based on the ANOVA model was used to determine a set of metrics that explain observers' preferences
Recherche de references sensorielles dans des collections de documents multimodaux issus de fonds patrimoniaux
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Scintillating sol-gel silica glasses and optical fibers for remote ionizing radiation dosimetry
No full textInternational audienceOptically activated glasses are essential to the development of new radiation detectionsystems. Among these systems, optical fiber sensors attract a huge interest due to theirsmall size, intrinsic immunity to electromagnetic interferences, flexibility and ability to beremotely interrogated. They also offer high spatial resolution of the measurement with thepossibility to work in hazardous, narrow and constrained environments. In the domain ofradiation dosimetry techniques, the application of optical fibers started with thermoluminescence(TL), and was followed by radiation induced attenuation (RIA), optically stimulatedluminescence (OSL) and radioluminescence (RL). For RL-based techniques, the scintillationsignal from the probe exposed to radiation can be recorded, allowing real-time dose-ratemeasurements, which makes this technique very interesting for applications in medical orsevere environmental domains.For nearly 20 years now, advances in the so-called ”polymeric” sol-gel technique in our laboratorieshave made it possible to reproducibly provide glassy rods made of dense silica dopedwith luminescent elements. The synthesis of such glass rods, capable of being drawn intocapillaries and then active fibers, required know-how and precise control of the hydrolysisand condensation reactions, inherent in this technique. Doping and densification also remaindelicate steps in this synthesis.Finally, the fusion-splicing and/or the assembly of luminescent sol-gel rods in a fiber structurehas given rise to multiple demonstrations of their dosimetry capabilities under differentradiations, using radioluminescence and optically or thermally stimulated luminescence processes.These processes, closely linked to the doping ions, such as Ce3+, Cu+, Tb3+, orGd3+, as well as to intrinsic matrix traps, are increasingly well understood thanks to amodel that can simulate optical signals under irradiation.The aim of this paper is to present the main results of dosimetry characterizations of suchsol-gel rods or fibers, combined with spectroscopic measurements as well as combined withthe optical signal simulation. The involved physical processes will be discussed to better understandthe behavior of these responses versus temperature and dose rate, the target beingto obtain total ionizing dose (TID) measuring probes independent of these parameters
Unveiling Ultrafast Dynamics: Atomistic-Continuum Modeling of Laser-Induced Phase Transitions in Silicon
No full textInternational audienceModern semiconductor applications demand precise laser processing at the nanometer scale, requiring a detailed understanding of phase transition and structural modification mechanisms. Accurate control over laser-induced processes in semiconductors is essential for generating predesigned surface structures and modifying the surface properties. In this study, we present a numerical investigation of non-equilibrium laser-induced phase transitions in silicon (Si) using a hybrid atomistic-continuum model. The model combines the strengths of Molecular Dynamics (MD) simulations for atomistic-scale descriptions of non-equilibrium phase transitions with a continuum approach to account for the effect of laser-generated free carriers. As compared to the ordinary continuum or MD approaches, this advanced framework, therefore, captures the kinetics of melting and ablation phenomena on one hand, and generation and diffusion of the electron-hole pairs, thermal diffusion, and the electron-phonon coupling processes during laser energy deposition on the other hand. We applied the model to determine the melting depth as a function of fluence for a 100 fs laser pulse at 800 nm. The results show that the stand-alone continuum approach underestimates the melting threshold as compared to the hybrid atomistic-continuum model by 46% originating from the detailed description of the melting kinetics, inherently given by MD. Additionally, we explored the effect of crystal orientation on melting dynamics and compared the results with the corresponding experimental measurement. Finally, the MD model is used to identify the conditions leading to the amorphization of the Si surface. The determined corresponding cooling rates are referred to the conditions realized in the experiments on femtosecond laser-silicon interaction. These findings provide valuable insights into experimental observations of Si surface structuring induced by ultrashort laser pulses.Key words: laser-material interactions, laser ablation, laser-induced melting, surface amorphization, atomistic-continuum model, ultrashort laser pulses, free carrier dynamic
Naturalight: A controlled illuminated environment to study light exposure impact on behavior and cognition in freely moving rats
No full textInternational audienceIn humans, scientific studies have shown that the increased use of screens at night and prolonged exposure to artificial light, particularly blue light, can significantly disrupt the organization of sleep-wake cycles and the functions that depend on them like memory. In rodents, moderate and even weak exposures to light have been shown to have various and either detrimental or beneficial effects on circadian rhythms, behavior, cognition. Yet, scattered and sometimes opposite effects are reported in the literature, which is largely attributed to differences in experimental conditions, especially on the definition and evaluation of the actual dose of light received. To address this issue, we have built an enclosure with controlled and characterized illumination. It can be used as a standalone experimental environment or eventually connected to naturalistic environment where several animals live constantly and interact freely within several housing modules, including the controlled illumination one
Just Project! Multi-Channel Despeckling, the Easy Way
No full textInternational audienceReducing speckle fluctuations in multi-channel SAR images is essential in many applications of SAR imaging such as polarimetric classification or interferometric height estimation. While single-channel despeckling has widely benefited from the application of deep learning techniques, extensions to multi-channel SAR images are much more challenging.This paper introduces MuChaPro, a generic framework that exploits existing single-channel despeckling methods. The key idea is to generate numerous single-channel projections, restore these projections, and recombine them into the final multi-channel estimate. This simple approach is shown to be effective in polarimetric and/or interferometric modalities. A special appeal of MuChaPro is the possibility to apply a self-supervised training strategy to learn sensor-specific networks for single-channel despeckling