Physical implementations of cryptographic algorithmscan leak sensitive information through different kindsof side-channels. This information can potentially be used forrecovering the secret key used in the algorithms. Recently, sidechannelattacks on CPU implementations of Advanced EncryptionStandard (AES) has been presented. Some of these attacksuse far-field electromagnetic radiation.In this thesis, we investigate if cross correlation can be used tolocate the part of the signal corresponding to the execution of theAES-encryption. We gather side-channel signal data containingencryption activity to create and test multiple templates forcorrelation. By evaluating the performance of the templates indifferent scenarios, we conclude that the method is useful andrelatively easy to implement compared to previous methods.Furthermore, our extraction method has a low execution timewhich gives it potential to be used in real-time attacks. / Fysiska implementationer av krypteringsalgoritmerkan läcka känslig information genom olika typer avsidokanaler. Informationen kan potentiellt användas för att återskapa algoritmernas hemliga krypteringsnycklar. Senastetiden har sidokanalsattacker mot CPU-implementationer av AdvancedEncryption Standard (AES) presenterats. Vissa av dessaattacker nyttjar utstrålande elektromagnetiska fjärrfält. I denna rapport undersöker vi om korskorrelation kananvändas för att hitta tidpunkten i signalen då AES-krypteringengenomfördes. Vi samlar in signaldata från sidokanalen sominnehåller krypteringsaktivitet, detta för att skapa och testa olikakorrelationsmallar. Genom att utvärdera mallarnas prestanda iolika scenarion kan vi sluta oss till att denna metod är användbarsamt lätt att implementera jämfört med tidigare metoder. Därtillvisar vår metods korta körtid att den har potential att användasi en realtidsattack. / Kandidatexjobb i elektroteknik 2021, KTH, Stockholm

The purpose of this study was to assess the metal content present in pine needles collected from an old shooting range known for elevated lead levels in the soil by different analytical methods. The focus on conifers originated from their evergreen nature year-round, and their ability to absorb potentially harmful elements. Research on needles as biomonitors for environmental contamination, particularly in areas affected by heavy metal pollution, has gained significant global attention. Four trees, two Norway spruces (Picea abies), and two Scots pines (Pinus sylvestris) were identified within the designated area. Samples of conifer needles were collected in plastic bags. The needles underwent washing, drying, and grinding into powder for subsequent digestion method and quantitative determination of metal content using ICP-MS and MPAES. The study focused on elements commonly found in various types of ammunition, specifically manganese, iron, nickel, copper, zinc, molybdenum, antimony, and lead. Results obtained from both analytical methods, which was only manganese, showed statistically significant differences. During the analysis, only manganese could be quantified using MPAES, as the other analytes were below the detection limit. For ICP-MS, the LOD values were much lower, making this method more suitable, as all analytes were above LOD and could be quantified. The recovery values for the CRM were good for all elements when ICP-MS was utilized. However, the calculated recovery value for manganese decreased based on the results obtained from MPAES compared to the calculated recovery value for manganese based on the results obtained from ICP-MS. Interestingly, the analysis of conifer needles revealed no noticeable contamination from the shooting range. Instead, it highlighted variances among different pine needle species. The metal content in the pine needles remained within acceptable limits according to external literature sources.

In this Thesis experimental studies of nano-clusters using synchrotron radiation based photoelectron (UPS and XPS) and Auger Electron Spectroscopy (AES) are presented. The investigations may be divided into two parts where the first reports on the structure of heterogeneous two component clusters, and the second concerns electronic decay processes. Using photoelectron spectroscopies as investigative tools the radial composition of heteroclusters of argon mixed with xenon, krypton or neon has been determined. Two methods of heterogeneous cluster production were employed: co-expansion and doping/pick-up. By analyzing the line shapes, energy positions, and widths of the spectral cluster features the radial composition of the clusters produced by co-expansion were found to form close-to-equilibrium structures, placing the component with larger cohesive energy in the cluster core while the second component was to varying degree segregated toward the surface. By instead using the doping/pick-up technique the opposite radial structures, i.e. far-from-equilibrium structures, may be formed. In the case of argon/krypton clusters a similar surface structure is formed regardless of production technique. The second part of the Thesis concerns post-ionization decay processes. Experimental evidence for the Interatomic Coulombic Decay process, a theoretically predicted decay channel, is presented in a study of homogeneous neon clusters. The time scale of the decay was determined to 6±1 fs for bulk atoms and >30 fs for surface atoms in the neon cluster, showing the connection between local geometry and dynamics of the decay. Another channel for electronic relaxation is Auger decay. This Thesis presents a method of disentangling the spectral surface and bulk responses from clusters in Auger spectra. Studies of argon clusters show that the AES technique is more surface sensitive than XPS, even at the same electron kinetic energy. Furthermore, the effect scattering of the photoelectron has on the Auger spectra was investigated. Special effort was put into explaining an experimentally observed photon energy dependent intensity appearing on the high-kinetic energy side on the Auger signal. We propose that this intensity is due to a solid state-specific photoelectron recapture process we name Pre-Auger Recapture (PAR), which affects the kinetic energy of the Auger electrons.

Atopic eczema is an incurable disorder of the skin. Sufferers are afflicted with hypersensitivity to environmental agents such as soaps (detergents), animal dander, pollen, specific foods and sometimes even water. Genetic mutations in atopic eczema compromise the development of the stratum corneum resulting in xerotic skin that is prone to cracking and increased permeability which leads to irritation due to the influx of exogenous material through the skin. The causes of atopic eczema are due to a combination of genetic and environmental factors and it is, therefore, a difficult disease to manage. Emollients and topical corticosteroids are the mainstay treatments for eczema. However, they do not treat the underlying cause of the flare-ups frequently seen in the condition; the damaged skin barrier. Defects in the skin barrier arise from premature desquamation of the stratum corneum. The main contributors to barrier breakdown are the up-regulation of skin proteases that are located in the skin. Since zinc is a known protease inhibitor, it would thus follow that a topical treatment for skin barrier repair should be developed. Therefore, the main objectives of this thesis are to successfully incorporate zinc into a formulation to develop a novel class of treatment for eczema and to assess the delivery of the element into the skin. In this thesis, methods to assess and characterise changes to skin barrier function and to extract and quantify zinc in the stratum corneum have been established. The development of two novel topically applied formulations containing zinc lactate as the active ingredient (1% w/w zinc lactate cream and a 2% w/v zinc lactate formulation) has been achieved and the uptake of zinc from the preparations in vitro determined. Further, the in vitro percutaneous penetration of zinc from three commercially available preparations has been investigated and compared to that recovered from the stratum corneum after passive diffusion with the novel zinc formulations. Additionally, in vivo uptake of zinc into human stratum corneum from Sudocremis ® reported. Scanning electron microscopy has revealed the distribution of zinc on the surface of skin treated with various formulations and has also allowed the efficiency of two cleaning procedures to be ascertained. The delivery of zinc from the novel topical formulation; 1% w/w zinc lactate cream, was more efficient than that the three commercial formulations and shows promise as a new approach to treat atopic eczema.

Made available in DSpace on 2016-04-25T16:45:08Z (GMT). No. of bitstreams: 1 Elias Barquete Albarello.pdf: 1196736 bytes, checksum: ddecfb7e3d553fe21e67003659251643 (MD5) Previous issue date: 2008-10-22 / In the context of the new model of the electric sector, the market projection has became a important tool for the sectorial planning and necessary in reason of the complexity of the national energy system, such in supply side and demand side. The social-economic and politic-institutional changes that will occur in the next decades allow to affirm, with reasonable security, that the future evolution of the energy demand, in particular of the electricity, will hardly follow the standards of the past, having to register differentiated movements duo to of the dynamic of the variable that determine its performance. In fact, the future is uncertain and it cannot be foreseen with exactness and security, being in the truth the result of discontinuities, ruptures and inflections of the standard past, highly influenced for new facts of the future and fruit of the social construction. Objectifying to analyze the importance of the construction of scenarios for the projection of electric energy market, a case study of the biggest electric energy distribution company of the country, AES Eletropaulo, was developed, in which it can verify the necessity of the use of scenario construction models, in reason of the results of the use of traditional methodologies, that might impact in the contract level of energy, conditioned by macroeconomic, social, institutional, ambient and technological factors, that present a relation of interdependence between itself, configuring an extensive net of mutual influences / No contexto do novo modelo do setor elétrico, a projeção de mercado tornou-se uma ferramenta de considerada importância para o planejamento setorial e necessária em razão da complexidade do sistema energético nacional, tanto do lado da oferta quanto do da demanda. As mudanças sócio-econômicas e político-institucionais que ocorrerão nas próximas décadas permitem afirmar, com razoável segurança, que a evolução futura da demanda de energia, em particular da eletricidade, dificilmente seguirá os padrões do passado, devendo registrar movimentos diferenciados decorrentes das dinâmicas das variáveis que determinam o seu desempenho. De fato, o futuro é incerto e não pode ser previsto com exatidão e segurança, sendo na verdade o resultado de descontinuidades, rupturas e inflexões do padrão passado, altamente influenciado por novos fatos portadores de futuro e fruto de uma construção social. Com o objetivo de analisar a importância da construção de cenários para a projeção de mercado de energia elétrica, foi conduzido um estudo de caso da maior distribuidora de energia elétrica do país, a AES Eletropaulo, na qual se pode verificar a necessidade de utilização de modelos de construção de cenários, referenciados no desenvolvimento desta pesquisa, em razão dos resultados decorrentes do uso de metodologias tradicionais, que poderão impactar no nível de contratação de energia, condicionada a fatores macroeconômicos, sociais, institucionais, ambientais, tecnológicos etc, que apresentam uma relação de interdependência entre si, configurando uma extensa rede de influências mútuas

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Les circuits microélectroniques sécuritaires sont de plus en plus présents dans notre quotidien (carte à puce, carte SIM) et ils renferment des informations sensibles qu'il faut protéger (numéro de compte, clé de chiffrement, données personnelles).<br /> Récemment, des attaques sur les algorithmes de cryptographie basées sur l'utilisation de fautes ont fait leur apparition. L'ajout d'une faute lors d'un calcul du circuit permet d'obtenir un résultat faux. À partir d'un certain nombre de résultats corrects et de résultats faux correspondants, il est possible d'obtenir des informations secrètes et dans certains cas des clés cryptographiques complètes.<br /> Cependant, les perturbations physiques utilisées en pratique (impulsion laser, radiations, changement rapide de la tension d'alimentation) correspondent rarement aux types de fautes nécessaires pour réaliser ces attaques théoriques.<br /> Dans ce travail, nous proposons une méthodologie pour tester les circuits face aux attaques par faute en utilisant de la simulation. L'utilisation de la simulation permet de tester le circuit avant la réalisation physique mais nécessite beaucoup de<br />temps. C'est pour cela que notre méthodologie aide l'utilisateur à choisir les fautes les plus importantes pour réduire significativement le temps de simulation.<br /> L'outil et la méthodologie associée ont été testés sur un circuit cryptographique (AES) en utilisant un modèle de faute utilisant des délais. Nous avons notamment montré que l'utilisation de délais pour réaliser des fautes permet de générer des fautes correspondantes à des attaques connues.

La formulation des lubrifiants utilisés dans l'automobile est complexe du fait du nombre important d'additifs mélangés aux huiles de base. Pour orienter le choix des formulateurs, il est non seulement nécessaire de connaître le mécanisme d'action de chaque additif mais aussi les interactions entre ces additifs. Pour mieux appréhender ces mécanismes, une démarche originale a été mise en place dans cette étude. Celle-ci consiste à simuler expérimentalement la lubrification en régime limite par la lubrification en phase gazeuse. Pour cela, des molécules de faible poids moléculaire modélisant les différents constituants d'un lubrifiant ont été introduites sous ultravide. Ce type d'expérience a pu être réalisé grâce au développement d'un nouveau Tribomètre à Environnement Contrôlé (TEC) connecté à un système d'analyse de surface. Cette technique permet de simplifier le système tribologique et d'étudier in situ les tribofilms formés en phase gazeuse par des analyses de surface (XPS/AES). Différentes molécules ont été étudiées : triméthylborate (TMB), triméthylphosphite (TMPi) et triméthylphosphate (TMPa) modélisant respectivement les additifs boratés et phosphorés des lubrifiants de transmission. Cette simulation expérimentale a pu être validée en comparant les résultats en phase gazeuse avec ceux obtenus en phase liquide. Des observations en microscopie optique et des analyses chimiques ont mis en évidence la formation de tribofilms. Les expériences réalisées en présence de TMB ont permis de confirmer les résultats de la littérature sur la formation d'un tribofilm non sacrificiel de borates de type « minéral ». Les expériences réalisées avec les molécules phosphorées ont permis de montrer la différence entre les phosphates et les phosphites, notamment la formation d'un composé de type phosphure de fer en présence de TMPi. Les analyses in situ sur les tribofilms obtenus en présence de TMPi ont permis de déterminer le mécanisme de formation du composé phosphure de fer. La réalisation de mélanges de gaz a permis également de mettre en avant les effets de synergie et d'antagonisme entre les additifs

Grâce à ses propriétés d'antioxydant, d'anti-usure et éventuellement d'extrême pression le dithiophosphate de zinc (ZDDP) fait partie des additifs les plus utilisés dans les lubrifiants pour moteurs thermiques. De nos jours, dans un souci de respect de l'environnement, de nouveaux lubrifiants possédant de bonnes performances en lubrification (frottement faible et usure limitée) sont développés en prenant compte des limitations d'utilisations actuelles du ZDDP. L'idée étant de réduire dans ceux-ci les teneurs en phosphore et soufre (Normes euros VI), éléments essentiels du ZDDP qui endommagent les pots catalytiques. L'objectif de cette thèse est l'étude du comportement tribologique du phosphate de zinc di alkyl (ZP) en comparaison avec le ZDDP. La méthodologie expérimentale étudiée pour comprendre le mécanisme d'action de ces additifs, associe des essais de frottement à descaractérisations physico-chimiques des surfaces frottantes après essais.Cette comparaison a été effectuée en fonction de la température (25°C et 100°C), la vitesse de glissement (25, 50 et 100 mm/s) et la concentration en additif (200 et 600 ppm dephosphore). Les meilleures actions anti-usure sont obtenues avec le ZDDP pour une température de 100°C et une vitesse de glissement de 100 mm/s et le ZP pour une température de 25°C et une vitesse de glissement de 25 mm/s. Les analyses de surface XPS, AES, XANES et MET-EDX ont permis de mettre en évidence la présence d'un film protecteur constitué principalement de phosphate de zinc, ceci pour les deux additifs.Une synergie de comportement tribologique a été mise en évidence avec un lubrifiantconstitué de ZP (usure faible) et d'oléate d'urée (frottement faible). Des essais complémentaires sur un tribomètre dynamique ont permis d'étudier le niveau de frottement du tribofilm formé à partir du ZDDP. Le caractère visqueux du tribofilm de ZDDP a été mis en évidence.

Implementation aspects of Advanced Encryption Standard (AES) Contest finalist algorithms (MARS, RC6, RIJNDAEL, SERPENT and TWOFISH) are studied on TMS320C54X processor. The C codes written by Brian Gladman in 1999 are adapted to TMS320C54X and the speed and memory usage values are compared with the adaptation of Karol Gorski and Michal Skalski&rsquo / s implementation in 1999. The effects of implementation environment are investigated by comparing the two implementations. The sensitivities of the finalist algorithms to plaintext, key and key length variations together with the possible reasons are studied and scrutinized. Three of the algorithms, MARS, RC6 and RIJNDAEL, are implemented on the same platform by using the assembler language. The results show that assembler implementations are improved with respect to C implementations 13% for MARS, 16-20% for RIJNDAEL and 21-28% for RC6.