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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.
21

Metodika měření kvality otisků prstu / Methodology of Fingerprint Image Quality Measurement

Oravec, Tomáš January 2018 (has links)
This thesis deals with the problem of methodology of fingerprint image quality measurement. The first task was to analyze already existing software used for fingerprint quality measurement called NFIQ (NIST Fingerprint Image Quality), evaluate its performance and identify weaknesses. In order to eliminate discovered NFIQ weaknesses, different fingerprint quality estimation methodology was introduced, and its results were compared to other methodologies.
22

Software pro hodnocení zdrojů entropie / Software for entropy resource evaluation

Šelinga, Martin January 2019 (has links)
This thesis is focused on exploring the sources of entropy. It includes a description of random number generators and tests used to evaluate entropy quality. Random number generator for Windows and Linux OS was created together with software for entropy evaluation. Subsequently, measurement of entropy was performed on physical workstations and Cloud environments.
23

Strategy in decision-making for cyber security standards / Strategi för valprocesser inom cyber säkerhets standarder

Gyllenberg, Marcus January 2022 (has links)
No description available.
24

Residual stress predictions in L-PBF Ti-6Al-4V NIST bridges using FEM

Luke, Caitlin Delaney 13 August 2024 (has links) (PDF)
Finite element modeling (FEM) is used to predict complex phenomena like part deformation and the formation of residual strain resulting from cyclical heating. A gap exists in current literature using FEM to investigate the effect of printing strategies on strain and deformation in Ti-6Al-4V NIST bridges built by laser powder bed fusion (L-PBF). This study compares thermomechanical finite element models incorporating three scan strategies commonly used in literature: meander, stripe, and checkerboard, for the fabrication of Ti-6Al-4V NIST bridges using L-PBF. FEM of each scan strategy uses four mechanical material models: elastic perfectly plastic, Johnson-Cook, eigenstrain, and Hill 1948. The models’ mechanical responses are compared to experimental data. The objective of this work is to compare the predicted strain states, part deflections, and runtimes for each scan strategy and mechanical material model. Ultimately, this work aims to use FEM to predict challenges from the as-printed stress state of the L-PBF part.
25

Rozšířený model pro hodnocení opatření bezpečnosti informací / Extended model for the evaluation of information security controls

Fischer, Radek January 2017 (has links)
Subject of the thesis is to create extended model for the evaluation of information security controls. Evaluation of security controls is one from many processes of risk management which is part of information security management system ISMS. Thesis contains the outline of issue of information security and introduce various publications of information security management. Two of these publications were chosen and are used in this thesis. It is ČSN ISO/IEC 27001:2014 and NIST 800_53. These two standards are used for creation of introduced model. Model itself is introduced in second part of the thesis. Model is connecting security controls from these two standards. If organization implements security controls from NIST 800_53, meet requirements defined in ČSN ISO/IEC 27001:2014; Apendix A. This model is also customized for evaluation of security controls and giving feedback to evaluator about state of implementation of security controls. This evaluation process is setup as evaluation of NIST 800_53 security controls and after that these data are recalculated into percentage value of implementation of security controls from Apendix A. Results of this process are most valuable for risk management, for planning an implementation of security controls and for improvement of already implemented.
26

Návrh metodiky budování bezpečnostního povědomí na střední škole / Design Methodology of Security Awareness at the Secondary School

Sobotková, Hana January 2017 (has links)
The diploma thesis addresses the topic of security awareness education at secondary schools. The goal is to develop a standardized methodology for building security awareness, which can be used by secondary schools to ensure the protection of their perimeter, their users and others from the user’s actions. The introductory part deals with the basic terminology, existing and forthcoming Czech and international legal acts, norms, regulations and certification in the area of information and cyber security. The practical part includes the methodology chapters describing the building of security awareness at secondary schools.
27

Modélisation, implémentation et caractérisation de circuits générateurs de nombres aléatoires vrais pour la certification de crypto-processeurs / Modeling, design and characterization of delay-chains based true random number generator

Ben Romdhane, Molka 01 October 2014 (has links)
Les nombres aléatoires sont indispensables dans de nombreuses applications notamment en cryptographie où l’aléa est utilisé dans les protocoles de sécurité. Les générateurs de nombres aléatoires, plus connus sous le nom de RNG comme “Random Number Generator” se déclinent en deux familles, les PRNG (Pseudo RNG) qui sont des générateurs de nombres aléatoires ayant des séquences déterministes et les TRNG (True RNG) qui sont des générateurs d’aléa “vrai”, donc non prédictibles. Les applications cryptographiques utilisent à la fois les TRNG et les PRNG. Un PRNG nécessite une valeur initiale, ou graine, qui peut être la sortie d’un TRNG. Les TRNG tirent profit de l’aléa des phénomènes physiques. Les TRNGs dans les technologies numériques comme les FPGAs font appel à des oscillateurs qui présentent l’inconvénient de pouvoir être attaqués par couplage harmonique. De façon à évaluer la qualité entropique d’un TRNG, des standards basés sur des tests statistiques ont été élaborés par des organismes de certification comme le NIST ou la BSI. Cependant, il est recommandé de formaliser, par le biais d’un modèle, le caractère stochastique de la génération d’aléa. Dans cette thèse, nous étudions une architecture de TRNG, peu coûteuse et robuste face aux attaques harmoniques car elle n’utilise pas d’oscillateurs. Ce TRNG extrait une variable aléatoire en exploitant à la fois les états métastables des bascules et les fluctuations temporelles (ou gigue) des signaux échantillonnés. Nous proposons par la suite un modèle stochastique qui nous permet de décrire le comportement aléatoire du TRNG indépendamment de la technologie ciblée. Les caractérisations et évaluations sur des circuits prototypes en technologies FPGA et ASIC montrent que l’architecture TRNG proposée génère de l’aléa de qualité et est robuste face aux variations environnementales / Random numbers are required in numerous applications namely in cryptography where randomness is used in security protocols. There are two main classes of Random Number Generators (RNG) : The Pseudo RNG (PRNG) which have a deterministic sequence, and the True RNG (TRNG) which generates unpredictable random numbers. Cryptographic applications use both TRNG and PRNG. The PRNG needs an initial value, or seed, which can be the output of a TRNG. In digital technologies, like FPGAs, TRNG are commonly based on oscillators which have the drawback of being biased by harmonic coupling. In order to assess the entropic quality of TRNGs, standards based on statistical tests have been elaborated by certification organisms namely the NIST and the BSI. However, it is recommended to formalize the stochastic behaviour of the randomness generation process. In this Ph.D, we address the design and quality evaluation of TRNGs in digital circuits. We study of a low-cost digital TRNG without oscillators, hence robust against harmonics attacks. The proposed TRNG exploits both the metastability phenomenon and the jitter noise in CMOS digital flip-flops to generate the random numbers. A stochastic model of this TRNG has been formalized. This model describes the random generation process regardless of the targeted technology. The characterization and evaluation on a prototype circuit, in FPGA and ASIC technologies, has shown that the proposed TRNG architecture generates randomness of good quality and is robust against environmental variations.
28

Suitability of the NIST Shop Data Model as a Neutral File Format for Simulation

Harward, Gregory Brent 07 July 2005 (has links)
Due to the successful application in internet related fields, Extensible Markup Language (XML) and its related technologies are being explored as a revolutionary software file format technology used to provide increased interoperability in the discrete-event simulation (DES) arena. The National Institute of Standards and Technology (NIST) has developed an XML-based information model (XSD) called the Shop Data Model (SDM), which is used to describe the contents of a neutral file format (NFF) that is being promoted as a means to make manufacturing simulation technology more accessible to a larger group of potential customers. Using a two step process, this thesis evaluates the NIST SDM information model in terms of its ability to encapsulate the informational requirements of one vendor's simulation model information conceptually and syntactically in order to determine its ability to serve as an NFF for the DES industry. ProModel Corporation, a leading software vendor in the DES industry since 1988, serves as the test case for this evaluation. The first step in this evaluation is to map the contents of ProModel's information model over to an XML schema file (XSD). Next, the contents of this new XSD file are categorized and compared to the SDM information model in order to evaluate compatibility. After performing this comparison, observations are made in relation to the challenges that simulation vendors might encounter when implementing the proposed NIST SDM. Two groups of limitations are encountered which cause the NIST SDM to support less than a third of the ProModel XSD elements. These two groups of limitations are: paradigm differences between the two information models and limitations posed due to the incomplete status of the NIST SDM specification. Despite these limitations, this thesis shows by comparison that XML technology does not pose any limitation which would invalidate its ability to syntactically represent a common information model or associated XML NFF. While only 28% of the ProModel element are currently supported by the SDM, appropriate changes to the SDM would allow the information model to serve as a foundation upon which a common information model and neutral file format for the DES industry could be built using XML technologies.
29

An Investigation of Methods to Improve Area and Performance of Hardware Implementations of a Lattice Based Cryptosystem

Beckwith, Luke Parkhurst 05 November 2020 (has links)
With continuing research into quantum computing, current public key cryptographic algorithms such as RSA and ECC will become insecure. These algorithms are based on the difficulty of integer factorization or discrete logarithm problems, which are difficult to solve on classical computers but become easy with quantum computers. Because of this threat, government and industry are investigating new public key standards, based on mathematical assumptions that remain secure under quantum computing. This paper investigates methods of improving the area and performance of one of the proposed algorithms for key exchanges, "NewHope." We describe a pipelined FPGA implementation of NewHope512cpa which dramatically increases the throughput for a similar design area. Our pipelined encryption implementation achieves 652.2 Mbps and a 0.088 Mbps/LUT throughput-to-area (TPA) ratio, which are the best known results to date, and achieves an energy efficiency of 0.94 nJ/bit. This represents TPA and energy efficiency improvements of 10.05× and 8.58×, respectively, over a non-pipelined approach. Additionally, we investigate replacing the large SHAKE XOF (hash) function with a lightweight Trivium based PRNG, which reduces the area by 32% and improves energy efficiency by 30% for the pipelined encryption implementation, and which could be considered for future cipher specifications. / Master of Science / Cryptography is prevalent in almost every aspect of our lives. It is used to protect communication, banking information, and online transactions. Current cryptographic protections are built specifically upon public key encryption, which allows two people who have never communicated before to setup a secure communication channel. However, due to the nature of current cryptographic algorithms, the development of quantum computers will make it possible to break the algorithms that secure our communications. Because of this threat, new algorithms based on principles that stand up to quantum computing are being investigated to find a suitable alternative to secure our systems. These algorithms will need to be efficient in order to keep up with the demands of the ever growing internet. This paper investigates four hardware implementations of a proposed quantum-secure algorithm to explore ways to make designs more efficient. The improvements are valuable for high throughput applications, such as a server which must handle a large number of connections at once.
30

Postkvantové šifry / Post-Quantum Ciphers

Novosadová, Tatiana January 2021 (has links)
Národný inštitút pre štandardy a technológie (NIST) zahájil proces na získanie, vyhodnotenie a štandardizáciu jedného alebo viacerých kryptografických algoritmov využívajúcich verejný kľúč prostredníctvom verejnej súťaže. Cieľom tejto dimplomovej práce je naštudovať dostupné postkvantové algoritmy pre ustanovenie kľúča, ktoré boli zverejnené v treťom kole tejto súťaže. Po dôkladnej analýze a porovnaní bol jeden zo študovaných algoritmov implementovaný s využitím knižníc dostupných pre daný algoritmus, následne bol program optimalizovaný a zdokumentovaný.

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