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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Parallel gaming related algorithms for an embedded media processor

Tolunay, John January 2012 (has links)
A new type of computing architecture called ePUMA is under development by the ePUMA Research Team at the Department of Electrical Engineering at Linköping University in Linköping. This contains several single instruction multiple data (SIMD) cores, which are called SIMD Units, where up to 64 computations can be done in parallel. The goal with the architecture is to create a low-power chip with good performance for embedded applications. One possible application is video games. In this work we have studied a selected set of video game related algorithms, including a Pseudo-Random Number Generator, Clipping and Rasterization & Fragment Processing, analyzing how well they fit the ePUMA platform.
32

Attaques électromagnétiques ciblant les générateurs d'aléa / Electromagnetic attacks on true random number generators

Bayon, Pierre 31 January 2014 (has links)
Aujourd'hui, nous utilisons de plus en plus d'appareils "connectés" (téléphone portable, badge d'accès ou de transport, carte bancaire NFC, ...), et cette tendance ne va pas s'inverser. Ces appareils requièrent l'utilisation de primitives cryptographiques, embarquées dans des composants électroniques, dans le but de protéger les communications. Cependant, des techniques d'attaques permettent d'extraire de l'information du composant électronique ou fauter délibérément son fonctionnement. Un nouveau médium d'attaque, exploitant les ondes électromagnétiques est en pleine expansion. Ce médium, par rapport à des techniques de fautes à base de perturbations par faisceau LASER, propose l'avantage d’être à relativement faible coût. Nous présentons dans cette thèse la résistance d'un type de bloc cryptographique, à savoir les générateurs de nombres réellement aléatoires, aux ondes électromagnétiques. Nous montrons qu'il est possible d'extraire de l'information sensible du champ électromagnétique produit par le composant électronique, et qu'il est également possible de perturber un générateur en le soumettant à un fort champ électromagnétique harmonique / Nowadays, our society is using more and more connected devices (cellphones, transport or access card NFC debit card, etc.), and this trend is not going to reverse. These devices require the use of cryptographic primitives, embedded in electronic circuits, in order to protect communications. However, some attacks can allow an attacker to extract information from the electronic circuit or to modify its behavior. A new channel of attack, using electromagnetic waves is skyrocketing. This channel, compared to attacks based on LASER beam, is relatively inexpensive. We will, in this thesis, present a new attack, using electromagnetic waves, of a certain type of cryptographic primitive: the true random number generator. We will show that it is possible to extract sensitive information from the electromagnetic radiation coming from the electronic device. We will also show that it is possible to completly modify the behavior of the true random number generator using a strong electromagnetic field
33

Optimalizace návrhových parametrů bezpečnostního přelivu / Optimization of Spillway Design Parameters

Pospíšilík, Šimon January 2019 (has links)
The diploma thesis is focused on the program development. The program is aimed at finding optimal design parameters for a two-pole emergency spillway. These parameters are the lengths of the spillway edges and their relative height arrangement. The program is based on the flood wave transformation simulation. Multi – gradient algorithm was used for optimization design parameters of a two-pole safety spillway.
34

Generování náhodných čísel pomocí magnetických nanostruktur / Random number generator based on magnetic nanostructures

Jíra, Roman January 2015 (has links)
Random number generation can be based on physical events with probabilistic character, or on algorithms that use complex or one-way functions, alternatively on both of these approaches. A magnetic vortex is a basic state of magnetization that forms in magnetic micro- and nanostructures of an appropriate shape, dimensions and material. Quantities of the magnetic vortex form randomly if ambient conditions are chosen eligibly. A concept of a true random number generator using a random switching of states of the magnetic vortex is presented in this thesis. This concept is realized and random numbers were experimentally generated and numbers were statistically analysed.
35

Efektivní generátor náhodných čísel v nízko-výkonových zařízení / Effective random number generator for limited devices

Michálek, Tomáš January 2017 (has links)
This thesis solves the problem of generating random numbers on low-power devices. Author describes possible ways of generating and implements selected generators of (pseudo)random numbers on MSP430F5438A. 4 generators were added by the enhancement of one of them and a new generator was created, using the phenomenon of temperature change in the surroundings. For each generator, test sequences were generated and these sequences were tested by the Dieharder, STS-NIST, and Visual Test. The output of the thesis is the functional implementation of the generators, their testing by statistical methods and their comparison between each other.
36

Development of a QRNG front-end for shot noise measurement : analysis of quantum shot noise originating from photodiodes / Utveckling och analys av förstärkt skottbrus från fotodioder för applikation inom kvantslumptalsgenerering

Clason, Martin January 2023 (has links)
As one of the more mature quantum technologies, quantum random number generators (QRNGs) fill an important role in producing secure and private keys for use in cryptogra- phy in e.g. quantum key distribution (QKD) systems. Many available QRNGs are expen- sive and optical QRNGs often require complex optical setups. If a reliable QRNG could be implemented using less expensive components they could become more widespread and be used in common applications like encryption and simulation. Shot noise is a possible entropy source for these kinds of random number generators. For such a generator to be classified as a QRNG the origin of the shot noise must be controlled and verifiable. This project aims to investigate how an entropy source could be implemented using the shot noise generated by an illuminated photodiode. This requires the design and construction of the accompanying electro-optical front-end used to prepare a signal for sampling. The successful estimation of the electron charge e is used as a way to verify that shot noise is present in the sampled signal. Suitable component values and operating points are also in- vestigated and it is shown that quite low gain (10 000) is suitable for the current-to-voltage amplifier which amplifies the signal generated by the photodiode. For this configuration an estimate of e was achieved with a relative error of 3%. In conclusion this is a promising and interesting approach for generating random numbers at high rates and at low cost. Whether the correct estimation of e is enough to certify that the device is sampling noise from the quantum regime is however not completely clear and further investigation is likely needed.
37

Kryptografický protokol s veřejným klíčem / Cryptography protocol with public key

Fujdiak, Radek January 2013 (has links)
The Master thesis is an introduction to cryptology. The Thesis describe cryptosystems and selects one ideal cypher for low-power microcontroler. In thesis provides manual for instal development program COde Composer Studio, basic implementation of selected cryptosystem with small numbers and suggestion for implementation selected cyptosystem with big numbers.
38

Programy pro výpočet nejistoty měření metodou Monte Carlo / Programs for calculating measurement uncertainty using Monte Carlo method

Novotný, Marek January 2015 (has links)
The thesis deals with establishing uncertainties of indirect measurements. It focuses primarily on random number generators in software enabling the calculation of mea-surement uncertainties using Monte Carlo. Then it focuses on the uncertainty calculati-on indirect measurement as the Monte Carlo method and the classical numerical met-hod. The practical part deals with the verification of randomness generators numbers contained in various softwares. It also deals with the determination of uncertainties indi-rect current measurements by both above-mentioned methods and then comparing and evaluating the values achieved.
39

Analyse de fiabilité de circuits logiques et de mémoire basés sur dispositif spintronique / Reliability analysis of spintronic device based logic and memory circuits

Wang, You 13 February 2017 (has links)
La jonction tunnel magnétique (JTM) commutée par la couple de transfert de spin (STT) a été considérée comme un candidat prometteur pour la prochaine génération de mémoires non-volatiles et de circuits logiques, car elle fournit une solution pour surmonter le goulet d'étranglement de l'augmentation de puissance statique causée par la mise à l'échelle de la technologie CMOS. Cependant, sa commercialisation est limitée par la fiabilité faible, qui se détériore gravement avec la réduction de la taille du dispositif. Cette thèse porte sur l'étude de la fiabilité des circuits basés sur JTM. Tout d'abord, un modèle compact de JTM incluant les problèmes principaux de fiabilité est proposé et validé par la comparaison avec des données expérimentales. Sur la base de ce modèle précis, la fiabilité des circuits typiques est analysée et une méthodologie d'optimisation de la fiabilité est proposée. Enfin, le comportement de commutation stochastique est utilisé dans certaines nouvelles conceptions d'applications classiques. / Spin transfer torque magnetic tunnel junction (STT-MTJ) has been considered as a promising candidate for next generation of non-volatile memories and logic circuits, because it provides a perfect solution to overcome the bottleneck of increasing static power caused by CMOS technology scaling. However, its commercialization is limited by the poor reliability, which deteriorates severely with device scaling down. This thesis focuses on the reliability investigation of MTJ based non-volatile circuits. Firstly, a compact model of MTJ including main reliability issues is proposed and validated by the comparison with experimental data. Based on this accurate model, the reliability of typical circuits is analyzed and reliability optimization methodology is proposed. Finally, the stochastic switching behavior is utilized in some new designs of conventional applications.
40

Bezpečné kryptografické algoritmy / Safe Cryptography Algorithms

Mahdal, Jakub January 2008 (has links)
This thesis brings a reader an overview about historical and modern world of cryptographic methods, as well evaluates actual state of cryptographic algorithm progressions, which are used in applications nowadays. The aim of the work describes common symmetric, asymmetric encryption methods, cryptographic hash functions and as well pseudorandom number generators, authentication protocols and protocols for building VPNs. This document also shows the basics of the successful modern cryptanalysis and reveals algorithms that shouldn't be used and which algorithms are vulnerable. The reader will be also recommended an overview of cryptographic algorithms that are expected to stay safe in the future.

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