En biologie clinique, disposer de mesures fiables et comparables, indépendamment du temps et du laboratoire, est primordial afin de permettre une prise en charge et un suivi adaptés des patients. Le moyen privilégié est d’établir la traçabilité métrologique des résultats de mesure aux unités du système international (SI), notamment par le biais de méthodes de référence et de matériaux de référence certifiés d’ordre supérieur. Ces travaux de thèse se sont attachés à caractériser deux méthodes de référence primaires candidates. Une méthode d’énumération absolue des lipoprotéines par ES-DMA pour l’évaluation du risque cardiovasculaire a été développée et caractérisée. Les résultats obtenus ont mis en évidence certaines limitations instrumentales rendant l’établissement de la traçabilité au SI difficile. Malgré les avantages certains de cette méthode pour l’analyse avancée de lipoprotéines, la fidélité et la robustesse des mesures ne sont pas suffisantes pour la considérer comme méthode de référence primaire. Une méthode de quantification de l’hémoglobine glyquée HbA1c, un biomarqueur du diabète sucré, par LC-MS/MS associée à la dilution isotopique a été mise en place et validée. La traçabilité au SI des résultats de dosage a été établie, toutefois, les incertitudes de mesures demeurent élevées et la comparabilité avec la méthode de référence IFCC reste à évaluer sur un nombre plus significatif d’échantillons et de laboratoires. Pour conclure, ces travaux ont mis en évidence les défis associés à la mise en place de nouvelles chaînes de traçabilité ainsi que les problématiques liées au développement de méthodes de référence primaires pour le dosage de biomarqueurs complexes. / Ensuring reliability and between-laboratory comparability of in-vitro diagnostic test results is essential for appropriate and internationally harmonized decision making and patient follow-up. To this end, a privileged way is to establish results metrological traceability to the international system of units (SI) through the development of primary reference methods and higher order reference materials. This thesis aimed at characterizing two candidate primary reference procedures.A method for lipoprotein absolute quantification by ES-DMA for cardiovascular diseases risk assessment was developed and characterized. Results evidenced some advantages of this method compared to other advanced lipoprotein testing assays, but some instrumental weaknesses make the establishment of results traceability to the SI difficult in the current state-of-the-art. Precision and robustness are additionally not sufficient for this method to be considered as a primary reference method.A method for the quantification of glycated hemoglobin HbA1c, a biomarker of diabetes mellitus, by LC/MS/MS associated to isotopic dilution was implemented and validated. Results traceability to the SI units could successfully be established. However, measurement uncertainties remain large and comparability with the IFCC reference method is still to be further assessed on a significant number of samples and laboratories.To conclude, this study highlighted the challenges associated with the implementation of new traceability chains and the difficulties related to the development and characterization of primary reference procedures for the quantification of complex biological markers.

This diploma’s thesis discourses the cryptographic systems and ciphers, whose function, usage and practical implementation are analysed. In the first chapter basic cryptographic terms, symmetric and asymetric cryptographic algorithms and are mentioned. Also usage and reliability are analysed. Following chapters mention substitution, transposition, block and stream ciphers, which are elementary for most cryptographic algorithms. There are also mentioned the modes, which the ciphers work in. In the fourth chapter are described the principles of some chosen cryptographic algorithms. The objective is to make clear the essence of the algorithms’ behavior. When describing some more difficult algorithms the block scheme is added. At the end of each algorithm’s description the example of practical usage is written. The chapter no. five discusses the hardware implementation. Hardware and software implementation is compared from the practical point of view. Several design instruments are described and different hardware design programming languages with their progress, advantages and disadvantages are mentioned. Chapter six discourses the hardware implementation design of chosen ciphers. Concretely the design of stream cipher with pseudo-random sequence generator is designed in VHDL and also in Matlab. As the second design was chosen the block cipher GOST, which was designed in VHDL too. Both designs were tested and verified and then the results were summarized.