Compiler-based Countermeasure Against Fault Attacks

International audiencePhysical attacks especially fault attacks represent one themajor threats against embedded systems. In the state ofthe art, software countermeasures against fault attacks areeither applied at the source code level where it will verylikely be removed at compilation time, or at assembly levelwhere several transformations need to be performed on theassembly code and lead to considerable overheads both interms of code size and execution time. This paper presentsthe use of compiler techniques to efficiently automate theapplication of software countermeasures against instruction-skip fault attacks. We propose a modied LLVM compilerthat considers our security objectives throughout the compi-lation process. Experimental results illustrate the effective-ness of this approach on AES implementations running onan ARM-based microcontroller in terms of security overheadcompared to existing solutions

Falling under the control of a different type of owner : risk-taking implications for Banks

European banks have experienced significant changes in the type of entity that owns them (another bank, an individual or a family, a non-financial company, an institutional investor, a government, a foreign entity, a domestic entity…). In this paper, we look at the influence of ownership type changes on performance. Working with a panel of commercial banks from 17 European countries, we find that although banks that experience a change in ownership type do not exhibit lower or higher risk or profitability than other banks, their risk and profitability is significantly affected after the change takes place. The type of the acquirer plays a significant role in explaining the observed changes. When the acquirer is a non-financial company, the state or an institutional investor, the level of risk increases after the change while the level of profitability remains unchanged. Conversely, when the acquirer is a bank, we find that the level of risk-adjusted profitability decreases. Banks acquired by a different type of owner during the global financial crisis do not perform better or worse than they did before

Effet de l’empilement des anodes de carbone pendant la cuisson sur leur densification et sur leur résistivité électrique

De nos jours, le seul procédé industriellement applicable pour la production de l’aluminium est connu sous le nom du procédé de Hall-Héroult. Le procédé utilise essentiellement des matériaux à base de carbone comme électrodes (anode et cathode). La productivité et l’efficacité énergétique du procédé sont étroitement liées à la qualité de l’anode (uniformité et stabilité des propriétés requises). Dans ce projet, nous avons étudié différents paramètres pouvant influencer l’uniformité des propriétés finales des anodes lors de leur cuisson principalement par la détermination de la résistivité électrique. Le processus de cuisson est la dernière étape du procédé de fabrication des anodes. Il s’agit d’une étape très critique, car c’est ici que les anodes subissent les plus importantes transformations microstructurales leur conférant les propriétés requises à leur utilisation dans le procédé de Hall-Héroult. Pendant la cuisson, les anodes sont empilées dans un four et cuites suivant des profils de température prédéfinis. Cela entraine la génération de contraintes mécaniques dans les anodes, causées par l’empilement, combinées aux transformations thermochimiques, causées par le processus de cuisson. La conséquence de ce phénomène peut mener à une anisotropie au niveau des propriétés des anodes. L’hypothèse est que lors de la cuisson, les anodes supérieures peuvent générer des pressions externes sur les anodes inférieures, provoquant ainsi le réarrangement des particules de coke dans la structure interne de l’anode. Ce changement pourrait mener à la réduction de la distance entre les particules affectant possiblement la résistivité électrique. Dans ce travail, la variation de la résistivité électrique d’une série d'anodes industrielles en fonction de leur position dans les fours de cuisson a été examinée dans un premier temps. Ensuite, à travers des travaux expérimentaux, menés en laboratoire, des échantillons d'anodes ont été fabriqués et cuits sous différentes pressions externes. Enfin, leur résistivité électrique a été déterminée afin d’établir une relation entre la force mécanique appliquée et la résistivité électrique.Nowadays, the only industrially applicable process to produce aluminum is known as the Hall-Héroult process. The process essentially uses carbon-based materials as electrodes (anodes and cathodes). The productivity and energy efficiency of the process is closely linked to the quality of the anodes (uniformity and properties variations). In this project, we studied different parameters that could influence the uniformity of the anode final properties by mainly determining their electrical resistivity. The baking process is the last step in the anode manufacturing process. This is a very critical step while the anodes undergo the most significant microstructural transformations giving them the properties required for their use in the Hall-Héroult process. During baking, the anodes are stacked in the furnace and baked according to predefined temperature profiles leading to the generation of mechanical stresses, due to stacking, combined with thermochemical transformations, due to the baking process. The consequence of this phenomena can lead to anisotropy in terms of anode internal properties. The hypothesis is that during baking, the upper anodes can exert an external pressure on the lower anodes, thus causing the rearrangement of the coke particles in the internal structure of the anode. This change could lead to a reduction in the distance between particles, possibly affecting the electrical resistivity. In this work, the variations in the electrical resistivity of a series of industrial anodes as a function of their position in the baking furnace were first examined. Then, through experimental work carried out in the laboratory, anode samples were fabricated and baked under different external pressures. Finally, their electrical resistivity was determined to establish a relationship between the applied mechanical force and the electrical resistivity

La protection des droits de l’enfant face au travail : la nécessité d’un changement de perspective par l’extension du concept de travail décent et l’application de l’approche basée sur les droits de la personne

La présente thèse cherche à démontrer que, face aux limites de l’approche abolitionniste dans l’appréhension du travail de l’enfant, approche véhiculée principalement par l’Organisation internationale du travail (OIT), il est possible d’explorer d’autres voies en vue de la protection des droits de l’enfant travailleur, au nombre desquelles figure l’application d’une approche basée sur les droits de l’enfant et du travail décent adapté à l’enfant. Cette démonstration repose principalement sur deux points. Dans un premier temps, il s’est agi de démontrer que l’approche abolitionniste, fondée essentiellement sur une définition négative du travail de l’enfant et sur le seul critère de l’âge, présente des limites parmi lesquelles le confinement de l’enfant travailleur dans l’illégalité et le risque d’abus d’une part et, d’autre part, la non implication de ce dernier dans la mise en œuvre de ses droits notamment par le biais de la participation comme le stipule l’article 12 de la Convention relative aux droits de l’enfant. Dans un second temps, la combinaison de l’approche basée sur les droits de la personne et du concept de travail décent s’est avéré une avenue prometteuse en ce sens que cette approche, proche de la théorie de droits de l’enfant, est susceptible de permettre une participation efficience de l’enfant travailleur dans la mise en œuvre de ses droits tant substantifs que procéduraux grâce à un travail reconnu et adapté à sa condition. L’ensemble de ces éléments de démonstration est basé sur l’analyse de diverses sources, dont les instruments internationaux portant sur le phénomène de travail de l’enfant et sur les droits de l’enfant, la doctrine pertinente, les pratiques et politiques des institutions internationales, les commentaires généraux des organes de mise en œuvre des droits de la personne en général et des droits de l’enfant en particulier, etc. En conclusion, il est possible d’affirmer qu’une approche basée sur les droits de l’enfant, supportée par un travail décent adapté au travail de l’enfant, est à même de contribuer efficacement à la protection de l’enfant travailleur

Runtime Code Polymorphism as a Protection against Physical Attacks

International audienceWe present a generic framework for runtime code polymorphism,applicable to a large class of computing platforms up to embeddedsystems with low computing resources (e.g. microcontrollers withfew kilo-bytes of memory). Code polymorphism is dened as the abilityto change the observable behaviour of a software component withoutchanging its functional properties. In our framework, code polymorphismis achieved thanks to runtime code generation, which oers many leversfor code transformations: we describe the use of random register allocation,random instruction selection, instruction shuing and insertion ofnoise instructions.We evaluate the eectiveness of our framework againstdierential power analysis and its overhead impact. As compared to areference implementation of AES where the cipher key could be recoveredby DPA in less than 50 traces in average, in our implementation thekey cipher could not be extracted after 10000 traces. Our experimentalevaluation shows a moderate impact in terms of performance overhead

Ownership Structure and Bank Efficiency in the asia pacific region

This paper focuses on efficiency measures of banks from six countries in Southeast and East Asia. We use a two-stage approach to study the post-crisis period 1999-2004. We first estimate technical efficiencies using Data Envelopment Analysis and test for cross-country differences. Efficiency scores are relatively high for South Korea and relatively low for the Philippines. We then investigate the link between ownership structure and efficiency controlling for various factors such as size, risk and the economic environment. We find that efficiency scores are higher for banks which are held by minority private shareholders and banks that are foreign-owned

Ownership Structure and Bank Efficiency in Six Asian Countries

International audienceThis paper focuses on efficiency measures of banks from six countries in Southeast and East Asia. We use a two-stage approach to study the post-crisis period 1999-2004. We first estimate technical efficiencies using Data Envelopment Analysis and test for cross-country differences. Efficiency scores are relatively high for South Korea and relatively low for the Philippines. We then investigate the link between ownership structure and efficiency controlling for various factors such as size, risk and the economic environment. We find that efficiency scores are higher for banks which are held by minority private shareholders and banks that are foreign-owned

Ornstein-Uhlenbeck Process via Conflated Drive of Brownian Motion and Lévy Process and its Application

Non-linear time series and linear models were not designed to detect probabilistic process that are depict by velocity and drift associated to returns the way Ornstein-Uhlenbeck stochastic process describes diffusion and velocity associated to series or waves influenced by Brownian motion or Lévy process.  In this research, Brownian motion and Lévy process were conflated as driving force for Ornstein-Uhlenbeck process with its solution applied to Naira-Dollar exchange rates from 2009-2019.The drift and diffusion estimates for the Ornstein-Uhlenbeck process driven by Brownian motion and Lévy process are realization of AR (1) with 2.991 and 0.1672 respectively. The AR(1) realization for the Ornstein-Uhlenbeck process was stationary with estimate  that lies outside the unit circle. The AIC, BIC, RMSE, and MSE for the Ornstein-Uhlenbeck process were estimated to be 483.7572, 483.4782, 0.00101, and 8.395 respectively, compare to estimates of the same indexes for AR (1) of 767.5, 634.09, 0.3819, and 23.48. The criterion via the residuals from the Ornstein-Uhlenbeck process was smaller, which connotes that the errors approximated in using drift, Brownian motion and to estimate  is relatively small via the Ornstein-Uhlenbeck process. Keywords: Brownian motion; Drift; Diffusion; Lévy process; Ornstein-Uhlenbeck Process DOI: 10.7176/MTM/11-3-02 Publication date:May 31st 202

A Template Attack Against VERIFY PIN Algorithms

International audienceThis paper presents the first side channel analysis from electromagnetic emissions on VERIFY PIN algorithms. To enter a PIN code, a user has a limited number of trials. Therefore the main difficulty of the attack is to succeed with very few traces. More precisely, this work implements a template attack and experimentally verifies its success rate. It becomes a new real threat, and it is feasible on a low cost and portable platform. Moreover, this paper shows that some protections for VERIFY PIN algorithms against fault attacks introduce new vulnerabilities with respect to side channel analysis