Les attaques par canaux cachés telles que les attaques par analyse de la consommation sont une menace pour la sécurité des circuits intégrés. Elles exploitent les fuites physiques émises par les circuits lors des calculs cryptographiques pour récupérer les informations secrètes qu'ils contiennent. De nombreuses contremesures, notamment matérielles, ont donc été proposées par la communauté dans le but de protéger les crypto-systèmes contre ce type d'attaques. Malgré leur efficacité, leur inconvénient majeur est leur surcoût important en surface, vitesse et consommation. Cette thèse a pour objectif de proposer des contremesures avec un faible coût au niveau matériel visant à réduire ces fuites et offrant un bon compromis entre sécurité et surcoûts. Pour cela, nous identifions tout d'abord les principales sources de fuites d'un crypto-système intégrant une architecture matérielle itérative d'un algorithme symétrique. Puis nous proposons plusieurs contremesures, à faible coût matériel, qui visent à réduire ces fuites. Enfin, nous évaluerons la robustesse de nos solutions face aux attaques par canaux cachés. / Side channel attacks such as power analysis attacks are a threat to the security of integrated circuits.They exploit the physical leakage of circuits during the cryptographic computations to retrieve the secret informations they contain. Many countermeasures, including hardware, have been proposed by the community in order to protect cryptosystems against such attacks. Despite their effectiveness, their major drawback is their significant additional cost in area, speed and consumption. This thesis aims at proposing low cost countermeasures able to reduce the leaks and offering a good compromise between security and costs. First we identify the main sources of leakage of a cryptographic system that integrates an iterative hardware architecture of a symetric algorithm. Then we propose several low cost countermeasures, which aim at reducing this leakage. Finally, we evaluate the robustness of our solutions against side channel attacks.

Cette étude avait pour objectif premier une caractérisation biomécanique du simple pas chez le sujet « normal ». À cet effet, on a considéré l’effet de la vitesse, ce qui a notamment permis de tester l’invariance de l’égalité entre la perturbation appliquée au corps lors de son accélération et la contre-perturbation lors de son freinage (CPA) permettant le retour au repos. Ainsi , le rôle des CPA se trouve explicité. Dans une seconde série expérimentale, on a considéré l’effet du frottement à l’arrêt du mouvement. L’objet de cette série était de caractériser la modification des caractéristiques biomécaniques chez le sujet « normal ». La caractérisation n’a pas soulevé de problèmes majeurs, l’effet de la vitesse se confirmant pour les deux coefficients de frottement (COF) considérés ( Téflon et Carrelage ). En revanche, les différences entre caractéristiques biomécaniques paraissent ne pas être significatives quand le COF diffère. Néanmoins, si l’on considère les résultats individuels, on constate que la durée des CPA tend à être systématiquement supérieure pour le COF le plus faible (Téflon), alors que le pic d’amplitude est systématiquement inférieur . Ces résultats incitent à approfondir l’étude de l’effet du frottement sur le simple pas. En conclusion , le simple pas semble être un paradigme permettant d’obtenir des résultats robustes et facilement utilisables pour étudier des personnes vieillissantes ou handicapées . / This study aimed to biomechanical characterization of a simple step among normal subjects. To this end, we considered the effect of speed, which has enabled to test the invariance of equality between the disturbance applied to the body during its acceleration and counter- perturbation during its breaking phase (CPA) to return to initial position. Also, the role of CPA is explained.In a second experimental series, we considered the effect of friction at the stop point of movement .The purpose of this series was to characterization of biomechanical characteristics modifications among normal subjects. So, the characterization did not raise any major problems, the effects of velocity is confirmed for both COF considered (Teflon and Tiles). How ever, the differences between biomechanical characteristics are not significant when the COF is different, but by considering the individual results, we have found that the duration of the CPA tends to be systematically higher for Teflon, contrary to the peak amplitude results.These results encourage further study of the effect of friction on the single step.In conclusion, the simple step seems to be a paradigm for obtaining robust results and easily usable to study old or handicapped peoples.

La cryptographie prend une place de plus en plus importante dans la vie des sociétés depuis que ses utilisateurs se rendent compte de son importance pour sécuriser divers aspects de la vie, depuis les moyens de paiement, de communication et de sauvegarde des éléments de la vie privée des citoyens, jusqu'à la sécurité nationale des pays et de leurs armées. Depuis une vingtaine d'années on sait que les algorithmes de cryptographie ne doivent pas seulement être sûrs mathématiquement parlant, mais que leurs implémentations dans un dispositif les rendent vulnérables à d'autres menaces par des voies d'informations alternatives : les canaux auxiliaires. Que ce soit la consommation électrique, le temps ou les émissions électromagnétiques, ... ces biais ont été évalués et depuis leur découverte les recherches de nouvelles attaques et protections se succèdent afin de garantir la sécurité des algorithmes. La présente thèse s'inscrit dans ce processus et présente plusieurs travaux de recherche traitant d'attaques et de contre-mesures dans le domaine de l'exploitation de canaux auxiliaires et d'injections de fautes. Une première partie présente des contributions classiques où l'on cherche à retrouver une clef cryptographique lorsque la seconde s’attelle à un domaine moins étudié pour l'instant consistant à retrouver les spécifications d'un algorithme tenu secret. / Cryptography is taking an ever more important part in the life of societies since the users are realising the importance to secure the different aspects of life from citizens means of payment, communication and records of private life to the national securities and armies. During the last twenty years we learned that to mathematically secure cryptography algorithms is not enough because of the vulnerabilities brought by their implementations in a device through an alternative means to get information: side channels. Whether it is from power consumption, time or electromagnetic emissions ... those biases have been evaluated and, since their discovery, the researches of new attacks follow new countermeasures in order to guarantee security of algorithms. This thesis is part of this process and shows several research works about attacks and countermeasures in the fields of side channel and fault injections analysis. The first part is about classic contributions where an attacker wants to recover a secret key when the second part deals with the less studied field of secret specifications recovery.

Background: Earlier research within “auditor selection” has found that reputation is a big contributing factor when clients are choosing their CPA (Certified Public Accountant) firm but there is no explanation to why this is. By combining the literature from “auditor selection” to the literature from “auditor reputation” and “corporate reputation” possible explanations can be found. By studying these areas of research two perspectives were distinguished from which the impact of the CPA firm’s reputation on the auditor selection process could be examined. With these perspectives we believe ourselves able to contribute to a deeper understanding of the relevance of reputation in the auditor selection process. Purpose: The purpose of this study is to examine the impact of the CPA firm’s reputation on the auditor selection process from an internal and external perspective. Method: By creating an internal and external perspective the study aims to dig deeper into the impact of reputation in an auditor selection process. These perspectives are used to categorise underlying motives for choosing a CPA firm over another. By dividing benefits gained by choosing a particular CPA firm to the external and internal perspective we can examine the the what kind of reputation has an impact on the respondents individual auditor selection process. Because of the difficulty of assessing the quality of the audit upfront the clients are forced to listen to the reputation of the CPA firms to receive desirable attributes according to the internal perspective. The external perspective believes that the CPA firm’s reputation can be used to manipulate the clients external stakeholders to benefit the client. Conclusion: This study shows that reputation is used as a selection criterion more than a determining factor in the auditor selection process. The final decision in not determined by positive reputation but a negative reputation can on the other hand terminate a CPA form from the selection process. Thereby a negative reputation is more impactful than a positive reputation on the auditor selection process. What kind of a reputation affects the client is based on their situation at the time of the selection process and their knowledge in accounting. The CPA firm’s reputation concerning all additional services was more impactful to the auditor selection process than the reputation concerning the audit. The respondents choice of a particular CPA firm were influenced by either the reputation of the CPA firm or earlier experiences of the firm. We found that earlier experiences were more impactful than a CPA firm’s reputation on the selection process. / Bakgrund: Att rykte har stor påverkan på klienters val av revisionsbyrå är något som tidigare forskning har kunnat konstatera. Dock vad detta beror på är inte utrett. Genom att kombinera litteraturen från “auditor selection” med litteraturen från “auditor reputation” och “corporate reputation” kan motiven bakom valet utredas. Genom att studera dessa litteraturområden kan två perspektiv urskiljas utefter vilka ryktets påverkan på valet av revisionsbyrå kan undersökas. Genom detta anser vi oss kunna ge en djupare förståelse till ryktets relevans i sammanhanget val av revisionsbyrå. Syfte: Studien syfte är att undersöka hur revisionsbyråns rykte kan påverkar klientens val av revisionsbyrå utifrån ett internt och ett externt perspektiv. Metod: Genom uppbyggnaden av studiens två idealtyper har ryktets påverkan på valet av revisionsbyrå utretts utifrån det interna och externa perspektivet. Dessa perspektiv används för att förklara bakomliggande motiv för att välja en revisionsbyrå framför en annan. Dessa har studerats genom att delas upp i olika nyttor som respondenterna vill förvärva. Då revisionens kvalitet är svår att utreda på förhand tvingas respondenterna lyssna till revisionsbyråns rykte för att finna dessa nyttor enligt det interna perspektivet. Det externa perspektivet söker istället revisionsbyråers rykte som anses kan påverka klientens externa intressenter till fördel för klienten. Slutsats: Studien visar att rykte är ett urvalskriterium snarare än en faktor som avgör valet. Det slutliga valet av revisionsbyrå baserades sällan på positiva rykten dock kan negativa rykte diskvalificera revisionsbyråer från urvalet. Därav har även ett negativt rykte större påverkan än ett positivt. Vilka rykten respondenterna lyssnade till är, enligt denna studie, beroende på klienternas situation samt deras kunskap inom revision. Revisionsbyråns rykte kring samtliga tilläggstjänster var av större vikt för valet än byråns rykte gällande kvaliteten på dess revisionstjänster. Respondenternas val påverkade antingen av rykte eller tidigare erfarenheter, där tidigare erfarenheter hade större påverkan än rykte.

The aim of the study in this thesis was to assess the stability of the mycotoxin, cyclopiazonic acid (CPA) in milk and dairy products processed from contaminated milk. A method was developed to detect CPA in milk and milk products using micellar electrokinetic capillary chromatography (MEKC), a technique of capillary electrophoresis (CE), which was rapid and non-labour-intensive. The quantifying efficiency of CE in detecting CPA was compared to Reverse Phase Liquid Chromatography. Heat-stability of CPA in milk was assessed under different conditions. A longer heat treatment of 60 degrees centigrade for 30 minutes led to a 10% decrease in the level of CPA. The results from this thesis demonstrate that CPA in milk at concentrations found in naturally contaminated milk could not be eliminated by the heat-treatment during milk processing, storage, processing and manufacture of dairy products. Occurrence of CPA in cheese curd, butter or cream following manufacture with contaminated milk was demonstrated. CPA is left in milk despite UV-visible radiation treatment with or without hydrogen peroxide and/or riboflavin. Chemical treatment, which is capable of completely eliminating CPA, is prohibited and impractical to use for milk treatment. Stability of CPA in milk and milk products confirms the potential of the toxin to reach consumers of dairy products. / Doctor of Philosophy (PhD)

<p>The interplay between magnetism and structure has been studied in magnetic multilayers by electronic structure calculations based on density functional theory and analyzed in terms of models. The main ideas behind the Korringa-Kohn-Rostocker Green’s function method are described and the implementation of the coherent potential approximation is outlined.</p><p>A simple model for the bilinear magnetic interlayer coupling in metallic multilayers is derived that elucidates the main characteristics of the effect such as coupling period and origin of damping. An analysis of two exotic effects on the magnetic interlayer coupling, Fermi surface nesting and magnetic enhancement is also performed. The Fermi surface nesting in CuPd for the (110) direction is shown to induce a sharp peak in the magnetic interlayer coupling amplitude for a Fe/CuPd/Fe system when the Cu concentration is 60% in the CuPd alloy. The high magnetic susceptibility in Pd is shown to have strong influence on the magnetic interlayer coupling in a Fe/Pd/Fe (100) system where it changes the amplitude, phase and induces an offset.</p><p>The relation between surface structure and magnetic properties in metallic multilayers is investigated in terms of a theory that is based on a symbiosis between experiment and theory. By calculating the total magnetic moment of a sample for a large range of possible interface structures and comparing to experimental results for equivalent samples a parameter that describes the interface structure is determined. This parameter is then shown to be universal for the particular combination of elements in the structure both as regards the calculated total magnetic moment as well as the magnetic interlayer coupling and the critical temperatures. </p>

The interplay between magnetism and structure has been studied in magnetic multilayers by electronic structure calculations based on density functional theory and analyzed in terms of models. The main ideas behind the Korringa-Kohn-Rostocker Green’s function method are described and the implementation of the coherent potential approximation is outlined. A simple model for the bilinear magnetic interlayer coupling in metallic multilayers is derived that elucidates the main characteristics of the effect such as coupling period and origin of damping. An analysis of two exotic effects on the magnetic interlayer coupling, Fermi surface nesting and magnetic enhancement is also performed. The Fermi surface nesting in CuPd for the (110) direction is shown to induce a sharp peak in the magnetic interlayer coupling amplitude for a Fe/CuPd/Fe system when the Cu concentration is 60% in the CuPd alloy. The high magnetic susceptibility in Pd is shown to have strong influence on the magnetic interlayer coupling in a Fe/Pd/Fe (100) system where it changes the amplitude, phase and induces an offset. The relation between surface structure and magnetic properties in metallic multilayers is investigated in terms of a theory that is based on a symbiosis between experiment and theory. By calculating the total magnetic moment of a sample for a large range of possible interface structures and comparing to experimental results for equivalent samples a parameter that describes the interface structure is determined. This parameter is then shown to be universal for the particular combination of elements in the structure both as regards the calculated total magnetic moment as well as the magnetic interlayer coupling and the critical temperatures.

Information transparency enhances corporate governance. In an attempt to reduce the information asymmetry between business insiders and outsiders and to allow outsiders to have more information for decision making by disclosing more corporate information voluntarily, the Taiwan Stock Exchange Corporation (TSEC) and Over-The-Counter Securities Exchange (OTCE) requested the Securities & Futures Institute (SFI) to implement an information disclosure and evaluation system for all publicly traded and OTC companies listed in TSEC. This study investigates the effects of the system on decision behavior of the investors, analysts, and auditors. Empirical results indicate that investors¡¦ ability of future earnings evaluation increases, analysts¡¦ earnings forecasts are more accurate, and the earnings forecasts dispersion among the analysts decreases after the system has been implemented. However, the implementation of the system has no effects on the types of audit opinion issued by auditors. Besides, the analysts¡¦ earnings forecasts are more accurate for the ¡§more transparent¡¨ companies. However, the differences of future earnings evaluation, earnings forecasts dispersion among the analysts and types of audit opinion between ¡§more transparent¡¨ and ¡§less transparent¡¨ companies are not significant. These results may provide implication to authorities for making related policies.

Today, the healthcare IT vendors develop interfaces for their products to comply with the IHE Profiles and test them with other vendors in annual events, called IHE Connactathons which are one week events organized to perform interoperability testing. Network configuration including hostnames, IP addresses,port numbers for healthcare services and URLs for the various web services used in IHE profiles are stored on online databases accessible from the IHE website. When all companies register for participation to the connectathon, a default configuration is created in the database, assigning default values for healthcare service specific parameters. Afterwards, a company is expected to use the configuration parameters from that database during the connectathon. Except from the connectathons, the vendors could not test their products with other vendors&rsquo / . In this thesis, research on IHE Configuration Management Tool based on IHE profiles, ebXML ebBP, CPP and CPA specifications is presented. The intention behind developing such a tool is to automate the creation and exchange of configuration information between IHE Actors in a Virtual Connectathon Portal. The results of this research enable the IHE product vendors to test their products in interactions with other vendors through the web anytime/anywhere by automatic business service interface configuration. The research enables the healthcare systems to engage with many trading partners at the same time automatically. The work presented in this thesis is realized as a part of IST-027065 RIDE project funded by European Commission.

?rea de concentra??o: Educa??o e Tecnologias aplicadas em Institui??es Educacionais. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-07-25T17:09:12Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) fabiano_kenji_aoki.pdf: 1033535 bytes, checksum: 2f0dc1bd0aca41817d8063177f6e1124 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-10-04T19:44:59Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) fabiano_kenji_aoki.pdf: 1033535 bytes, checksum: 2f0dc1bd0aca41817d8063177f6e1124 (MD5) / Made available in DSpace on 2018-10-04T19:44:59Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) fabiano_kenji_aoki.pdf: 1033535 bytes, checksum: 2f0dc1bd0aca41817d8063177f6e1124 (MD5) Previous issue date: 2017 / O tema da avalia??o de institui??es educacionais ? bastante complexo. Nasce do anseio natural de uma organiza??o em conhecer a si pr?pria e de exig?ncias legais e normativas de avalia??o atualmente existentes para todos os n?veis da educa??o, da b?sica ? superior. Passa pelos esfor?os de organiza??o, manuten??o e produ??o de informa??es que, ao mesmo tempo em que atendem a norma legal, transformam-se em valiosa ferramenta para a tomada de decis?es, quando sensibilizada a c?pula hier?rquica de uma institui??o sobre a import?ncia do processo de autoavalia??o institucional. O Sistema Nacional de Avalia??o da Educa??o Superior (SINAES), em vigor desde 2004, examina as institui??es de ensino superior (IES), os cursos de gradua??o e o desempenho dos estudantes. O presente trabalho teve por objetivo a elabora??o do manual de processo de autoavalia??o institucional com vistas a apoiar os trabalhos conduzidos pela Comiss?o Pr?pria de Avalia??o (CPA) das IES. A utiliza??o de manuais em ambientes corporativos contribui para a compreens?o e a consolida??o de conhecimentos inerentes ? ?rea de atua??o do profissional e para o norteamento das a??es de grupos de trabalho orientados para um mesmo objetivo. A metodologia utilizada envolveu pesquisas bibliogr?fica e documental, tendo em vista o estudo explorat?rio de enfoque qualitativo. / Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Educa??o, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The subject of evaluation of educational institutions is quite complex. It is born of the natural yearning of an organization to know itself and the legal requirements and evaluation regulations that currently exist for all levels of education, from basic to higher education. It goes through the efforts of organization, maintenance and production of information that, while complying with the legal norm, become a valuable tool for decision making, when sensitized the hierarchical leadership of an institution on the importance of the process of self-evaluation institution. The National System for the Evaluation of Higher Education (SINAES), in force since 2004, examines higher education institutions (HEIs), undergraduate courses and student performance. The objective of the present work was to elaborate a process manual of the institutional self-evaluation to support the work carried out by the Self-Evaluation Committee (CPA) of HEI. The use of manuals in corporate environments contributes to the understanding and consolidation of knowledge inherent in the professional's area of activity and to the orientation of work group actions oriented toward the same objective. The methodology used involved bibliographical and documentary research, in view of the exploratory study of a qualitative approach.