Like conventional networks, security is also a big concern in wireless sensor networks. However, security in this type of networks faces not only typical but also new challenges. Constrained devices, changing topology or susceptibility to unprecedented security threats such as node capture and node compromise has refrained developers from applying conventional security solutions into wireless sensor networks. Hence, developing security solutions for wireless sensor networks not only requires well security analysis but also offers a low power and processing consuming.In this thesis, we implemented security solution targeting IRIS sensor motes. In our implementation, a public key-based key exchange is used to establish shared secret keys between sensor nodes. These secret keys are used to provide authenticity, integrity and freshness for transmission data. Our implementation ensures the flexibility in integrating our solution with available TinyOS operating system. Additionally, the thesis work also focuses on evaluating the performance in wireless sensor networks both in memory and energy consuming.

Hybrid optical packet/circuit switched networking architectures are increasingly becoming an interesting research field. They integrate and combine the high resource utilization of statistically multiplexed packet switched networks with the low processing requirements and guaranteed quality of service provided by circuit switched networks. The aim of this thesis is to integrate the OpMiGua hybrid optical network with Ethernet. Specifically, the work is focused on the compatibility of the Ethernet’s loop-free topology protocols with the redundant multiple traffic service paths of OpMiGua. We analyse the problems and limitations imposed on the network architecture and propose our topology solution called the SM chain-connectivity. The analysis and the proposed schemes are verified based on results obtained from simulations. Furthermore, we design an integrated logical OpMiGua node that relies on an Ethernet switch instead of the Optical Packet Switch for the Statistically Multiplexed traffic. To date, to our knowledge there are no studies analysing the compatibility of Ethernet and its protection mechanisms in a hybrid optical network. This is the first work addressing the use of Ethernet in OpMiGua.

Cloud computing has gained remarkable popularity in the recent years by a wide spectrum of consumers, ranging from small start-ups to governments. However, its benefits in terms of flexibility, scalability, and low upfront investments, are shadowed by security challenges which inhibit its adoption. In particular, these highly flexible but complex cloud computing environments are prone to misconfigurations leading to security incidents, eg, erroneous exposure of services due to faulty network security configurations. In this thesis we present a novel approach in the security assessment of multi-tier architectures deployed on infrastructure clouds such as Amazon EC2. In order to perform this assessment for the currently deployed configuration, we automated the process of extracting the configuration using the Amazon API and translating it into a generic data model for later analysis. In the assessment we focused on the reachability and vulnerability of services in the virtual infrastructure, and presented a way for the visualization andautomated analysis based on reachability and attack graphs. We proposed a query and policy language for the analysis which can be used to obtain insights into the configuration and to specify desired and undesired configurations. We have implemented the security assessment in a prototype and evaluated it for practical andtheoretical scenarios. Furthermore, a framework is presented which allows the evaluation of configuration changes in the agile and dynamic cloud environments with regard to properties like vulnerabilities or expected availability. In case of a vulnerability perspective, this evaluation can be used to monitor the securitylevels of the configuration over its lifetime and to indicate degradations.

Nowadays, verification of programs is gaining increased importance. The software industry appears more and more interested in methods and tools to ensure security in their applications. Java Modeling Language has been successfully used in the past by programmers to express their intentions in the Design by Contract fashion in sequential programming. One of the design goals of JML was to improve the functional software correctness of Java applications. Regarding the verification of security properties, JML was mostly successful in Java Smart Card applets due to the specifics of these applications. In this thesis work we investigate the feasibility of JML to express high-level security properties in Java applications that have more realistic requirements and are implemented in the object oriented technology. We do a threat analysis of a case study regarding a medical clinic and derive the required security properties to secure the application. We develop a prototype application where we specify high-level security properties with JML and use a runtime assertion checking tool to verify the code. We model the functional behavior of the prototype that establishes the security proper-ties as a finite state automaton. Our prototype is developed based on this automaton. States and state transitions modeled in the automaton are expressed in the prototype with JML annotations and verified during runtime. We observe that currently available features in JML are not very feasible to capture the security related behavior of Java programs on the level of the entire application.

L'arrivée récente de plateformes véhiculaires connectées à internet permet la diffusion de contenus d'infodivertissement en flux poussés et tirés pour les conducteurs et les passagers en situation de mobilité d'une manière comparable aux appareils de communication nomades actuels. Toutefois, la voiture constitue un terminal d'accès très différent d'un téléphone portable que ce soit en termes de caractéristiques techniques, mais aussi en matière d'usages. Cette thèse aborde le sujet de la fourniture personnalisée du contenu multimédia pour les automobilistes. Une étude des caractéristiques techniques des plateformes d'infodivertissement, des types de contenus et de métadonnées nous permet dans un premier temps de cerner les contraintes d'une architecture de fourniture individualisée pour un véhicule. La mise en perspective de ces contraintes nous permet d'établir une architecture de fourniture de contenu à la demande, implémentée dans un prototype. Nous abordons ensuite le problème de la personnalisation suivant deux axes complémentaires : D'une part, la personnalisation active qui fait intervenir une interface homme machine multimodale que nous étudions dans le cadre spécifique d'un navigateur de bibliothèque musicale en ligne permettant de créer facilement des listes de lectures multicritères dans un véhicule ; et d'autre part, la personnalisation passive du contenu qui fait intervenir une modélisation du contexte de l'utilisateur. Nous discutons de la répartition de composants fonctionnels permettant cette personnalisation passive et construisons une architecture répartie prenant en compte la définition individualisée de préférences contextuelles et son intégration dans l'architecture multimédia présentée plus haut. Les différentes solutions proposées sont enfin évaluées selon des méthodes expérimentales faisant intervenir des utilisateurs et des méthodes dites expertes.

<p>In our homes and in the enterprise, in our leisure and in our professions, mobile computing is no longer merely "exciting;" it is becoming an essential, ubiquitous tool of the modern world. New and innovative mobile applications continue to inform, entertain, and surprise users. But, to make the daily use of mobile technologies more gratifying and worthwhile, we must move forward with new levels of sophistication. The Mobile App Stores of the future must be built on stronger foundations. </p><p>This dissertation considers a broad view of the challenges and intuitions behind a diverse selection of such new primitives. Some of these primitives will mitigate existing and fundamental challenges of mobile computing, especially relating to wireless communication. Others will take an application-driven approach, being designed to serve a novel purpose, and be adapted to the unique and varied challenges from their disparate domains. However, all are related through a unifying goal, to provide a seamless, enjoyable, and productive mobile experience. This dissertation takes view that by bringing together nontrivial enhancements across a selection of disparate-but-interrelated domains, the impact is synergistically stronger than the sum of each in isolation. Through their collective impact, these new "building blocks" can help lay a foundation to upgrade mobile technology beyond the expectations of early-adopters, and into seamless integration with all of our lives.</p> / Dissertation

No description available.

This paper aims at giving answers to the question of how and why mobile device usage patterns differ in China, Germany and the United States of America. Triangulation was chosen as the appropriate research method: qualitative date from focus groups is complemented with quantitative date from an online questionnaire. Firstly, a short overview over past research results on psychological differences between people from different cultures is given. Then, qualitative data gathered in focus groups is presented. Quantitative data on mobile device usage patterns from an online questionnaire in the three countries is presented. About 300 questionnaires were completed and evaluated. Many statistically significant effects from the quasi-variable culture could be found. For example, although almost all participants from all three cultures use mobile devices for communication purposes, the usage frequencies of other functions differ strongly. Cultures differ also in the acceptance of autonomous interventions by a technical system. Probable explanations for these differences and their consequences on HMI design are discussed. / Diese Veröffentlichung soll die Frage beantworten, wie und warum sich die Nutzungsmuster von mobilen Endgeräten in China, Deutschland und den USA unterscheiden. Als angemessene Untersuchungsmethode wurde die Triangulation ausgewählt: Qualitative Daten aus Fokusgruppen werden ergänzt durch quantitative Daten aus einem Online-Fragebogen. Zuerst wird ein kurzer Überblick über bestehende Forschungsergebnisse über psychologische Unterschiede zwischen Menschen aus verschiedenen Kulturen gegeben. Anschließend werden qualitative Daten aus Fokusgruppen und quantitative Daten aus einem Online-Fragebogen über Nutzungsmuster von mobilen Endgeräten präsentiert. Mehr als 300 Fragebögen wurden ausgefüllt und ausgewertet. Viele statistisch signifikante Auswirkungen der Quasi-Variable Kultur konnten gefunden werden. Während beispielsweise fast alle Teilnehmer aus allen drei Kulturen mobile Endgeräte für Kommunikationszwecke nutzen, unterscheiden sich die Nutzungshäufigkeiten anderer Funktionen stark. Die Kulturen unterscheiden sich auch in der Akzeptanz von autonomen Eingriffen durch ein technisches System. Mögliche Erklärungen für diese Unterschiede und deren Folgen für die Gestaltung von Mensch-Maschine-Schnittstellen werden diskutiert.

Thesis (Ph.D.) -- University of Texas at Arlington, 2009.

Thesis (M.S.)--University of Florida, 2002. / Title from title page of source document. Includes vita. Includes bibliographical references.