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The Global ETD Search service is a free service for researchers
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Security primitives for ultra-low power sensor nodes in wireless sensor networksHuang, An-Lun 05 May 2008 (has links)
The concept of wireless sensor network (WSN) is where tiny devices (sensor nodes), positioned fairly close to each other, are used for sensing and gathering data from its environment and exchange information through wireless connections between these nodes (e.g. sensor nodes distributed through out a bridge for monitoring the mechanical stress level of the bridge continuously). In order to easily deploy a relatively large quantity of sensor nodes, the sensor nodes are typically designed for low price and small size, thereby causing them to have very limited resources available (e.g. energy, processing power). Over the years, different security (cryptographic) primitives have been proposed and refined aiming at utilizing modern processor’s power e.g. 32-bit or 64-bit operation, architecture such as MMX (Multi Media Extension) and etc. In other words, security primitives have targeted at high-end systems (e.g. desktop or server) in software implementations. Some hardware-oriented security primitives have also been proposed. However, most of them have been designed aiming only at large message and high speed hashing, with no power consumption or other resources (such as memory space) taken into considerations. As a result, security mechanisms for ultra-low power (<500µW) devices such as the wireless sensor nodes must be carefully selected or designed with their limited resources in mind. The objective of this project is to provide implementations of security primitives (i.e. encryption and authentication) suitable to the WSN environment, where resources are extremely limited. The goal of the project is to provide an efficient building block on which the design of WSN secure routing protocols can be based on, so it can relieve the protocol designers from having to design everything from scratch. This project has provided three main contributions to the WSN field. Provides analysis of different tradeoffs between cryptographic security strength and performances, which then provide security primitives suitable for the needs in a WSN environment. Security primitives form the link layer security and act as building blocks for higher layer protocols i.e. secure routing protocol. Implements and optimizes several security primitives in a low-power microcontroller (TI MSP430F1232) with very limited resources (256 bytes RAM, 8KB flash program memory). The different security primitives are compared according to the number of CPU cycles required per byte processed, specific architectures required (e.g. multiplier, large bit shift) and resources (RAM, ROM/flash) required. These comparisons assist in the evaluation of its corresponding energy consumption, and thus the applicability to wireless sensor nodes. Apart from investigating security primitives, research on various security protocols designed for WSN have also been conducted in order to optimize the security primitives for the security protocols design trend. Further, a new link layer security protocol using optimized security primitives is also proposed. This new protocol shows an improvement over the existing link layer security protocols. Security primitives with confidentiality and authenticity functions are implemented in the TinyMote sensor nodes from the Technical University of Vienna in a wireless sensor network. This is to demonstrate the practicality of the designs of this thesis in a real-world WSN environment. This research has achieved ultra-low power security primitives in wireless sensor network with average power consumption less than 3.5 µW (at 2 second packet transmission interval) and 700 nW (at 5 second packet transmission interval). The proposed link layer security protocol has also shown improvements over existing protocols in both security and power consumption. / Dissertation (MEng (Computer Engineering))--University of Pretoria, 2008. / Electrical, Electronic and Computer Engineering / unrestricted
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Le rôle des juridictions supranationales de la CEMAC et de l'OHADA dans l'intégration des droits communautaires par les Etats membres / The role of supranational jurisdictions of CEMAC and OHADA in the integration of community Law by member StatesFipa Nguepjo, Jacques 04 July 2011 (has links)
La Cour de Justice Communautaire (CJC), la Cour des Comptes Communautaire (CCC) et la Cour Commune de Justice et d’Arbitrage (CCJA) sont les trois juridictions supranationales créées respectivement par les traités de la CEMAC et de l’OHADA pour renforcer les nouveaux processus d’intégration économique et juridique des Etats membres. Dans la mesure où ces juridictions exercent un contrôle juridictionnel déterminant de la norme communautaire, le premier contrôle étant effectué par les juridictions nationales des Etats parties, la conception, l’organisation, le fonctionnement, les caractéristiques, les rôles ou compétences de ces juridictions nouvelles ainsi que la destinée des décisions qu’elles rendent dans leurs fonctions strictement judiciaires ou dans celles accessoires d’appui à la procédure arbitrale, présentent un intérêt digne d’une recherche doctorale. S’il est apparu que des jalons supplémentaires d’efficacité des nouveaux processus d’intégration ont été plantés par la création desdites juridictions, il a également été constaté que des pesanteurs d’ordre juridictionnel, structurel ou fonctionnel continuent d’en retarder la vitesse de croisière. Les solutions que nous avons proposées pour surmonter ces difficultés se regroupent en une réorganisation des juridictions communautaires, une répartition claire des compétences entre elles, un renforcement de la procédure de contrôle du droit communautaire, une vulgarisation permanente du droit de l’intégration, une revalorisation des titres exécutoires, une clarification des fonctions du juge d’exécution, une restriction du domaine de l’immunité d’exécution, un réaménagement des procédures de recouvrement, une formation continue des acteurs de la justice, une amélioration de leur condition de travail et de vie, une résurgence de l’éthique morale, une réelle indépendance de la justice… C’est dire que l’étude met un accent sur les obstacles qui entravent les nouveaux processus d’intégration et propose des solutions pour parfaire les textes législatifs et leurs interprétations jurisprudentielles, dans la perspective d’accélérer le développement économique des Etats concernés en particulier, pour une meilleure prospérité globale des économies mondiales. / The Communautary Court of Justice (CCJ), the Communautary Court of Account (CCA) and the Common Court of Justice and Arbitration (CCJA) are the three supranational jurisdictions respectively created by EMCAC and OHBLA treaties to reinforce the new processes of economical and judicial integration for their member States. In the measure where these jurisdictions are competent to exercise a juridictional control, by determining the communautary norms, the first control being carried out by the national juridictions, the conception, the organisation, the functioning, the characteristics, the roles or competences of these new jurisdictions and also the destiny of the decisions they rend in their strictly judiciary functions or in their accessory functions of supporting the arbitral procedure, present an interest worthy of a doctorate research. If it appears that the supplementary Milestones of efficiency of the new processes of integration had been installed by the creation of the said jurisdictions, it had also been observed that the gravities of jurisdictional, structural or functional order continue to delay the speed of cruise. The solutions that we have proposed to overcome these difficulties involves the reorganization of communautary jurisdictions, the clearly distribution of competences between them, the reinforcement of the communautarian law control procedure, a permanent vulgarisation of integration law, a revalorisation of executary titles, a clarification of immunity of execution domain, a development of the recovery procedures, a continual training of judicial actors, and improvement of their working and living conditions, a resurgence of moral ethic, a real independence of the Justice… This means that the study put a stress on the obstacles which hold up the new processes of integration and propose solutions to perfect the legislative texts and their jurisprudential interpretations, in the perspective of accelerating the economic development of the concerned States, for the best global prosperity of the world’s economies.
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