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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.
51

Detekce časových postranních kanálů v TLS / Detection of Timing Side-Channels in TLS

Koscielniak, Jan January 2020 (has links)
Protokol TLS je komplexní a jeho použití je široce rozšířené. Mnoho zařízení používá TLS na ustanovení bezpečné komunikace, vzniká tak potřeba tento protokol důkladně testovat. Tato diplomová práce se zaměřuje na útoky přes časové postranní kanály, které se znovu a znovu objevují jako variace na už známé útoky. Práce si klade za cíl usnadnit korektní odstranění těchto postranních kanálů a předcházet vzniku nových vytvořením automatizovaného frameworku, který pak bude integrován do nástroje tlsfuzzer, a vytvořením testovacích scénářů pro známé útoky postranními kanály. Vytvořené rozšíření využívá program tcpdump pro sběr časových údajů a statistické testy spolu s podpůrnými grafy k rozhodnutí, zda se jedná o možný postranní kanál. Rozšíření bylo zhodnoceno pomocí nových testovacích skriptů a byla předvedena jeho dobrá schopnost rozlišit postranní kanál. Rozšíření spolu s testy je nyní součástí nástroje tlsfuzzer.
52

PROACTIVE VULNERABILITY IDENTIFICATION AND DEFENSE CONSTRUCTION -- THE CASE FOR CAN

Khaled Serag Alsharif (8384187) 25 July 2023 (has links)
<p>The progressive integration of microcontrollers into various domains has transformed traditional mechanical systems into modern cyber-physical systems. However, the beginning of this transformation predated the era of hyper-interconnectedness that characterizes our contemporary world. As such, the principles and visions guiding the design choices of this transformation had not accounted for many of today's security challenges. Many designers had envisioned their systems to operate in an air-gapped-like fashion where few security threats loom. However, with the hyper-connectivity of today's world, many CPS find themselves in uncharted territory for which they are unprepared.</p> <p><br></p> <p>An example of this evolution is the Controller Area Network (CAN). CAN emerged during the transformation of many mechanical systems into cyber-physical systems as a pivotal communication standard, reducing vehicle wiring and enabling efficient data exchange. CAN's features, including noise resistance, decentralization, error handling, and fault confinement mechanisms, made it a widely adopted communication medium not only in transportation but also in diverse applications such as factories, elevators, medical equipment, avionic systems, and naval applications.</p> <p><br></p> <p>The increasing connectivity of modern vehicles through CD players, USB sticks, Bluetooth, and WiFi access has exposed CAN systems to unprecedented security challenges and highlighted the need to bolster their security posture. This dissertation addresses the urgent need to enhance the security of modern cyber-physical systems in the face of emerging threats by proposing a proactive vulnerability identification and defense construction approach and applying it to CAN as a lucid case study. By adopting this proactive approach, vulnerabilities can be systematically identified, and robust defense mechanisms can be constructed to safeguard the resilience of CAN systems.</p> <p><br></p> <p>We focus on developing vulnerability scanning techniques and innovative defense system designs tailored for CAN systems. By systematically identifying vulnerabilities before they are discovered and exploited by external actors, we minimize the risks associated with cyber-attacks, ensuring the longevity and reliability of CAN systems. Furthermore, the defense mechanisms proposed in this research overcome the limitations of existing solutions, providing holistic protection against CAN threats while considering its performance requirements and operational conditions.</p> <p><br></p> <p>It is important to emphasize that while this dissertation focuses on CAN, the techniques and rationale used here could be replicated to secure other cyber-physical systems. Specifically, due to CAN's presence in many cyber-physical systems, it shares many performance and security challenges with those systems, which makes most of the techniques and approaches used here easily transferrable to them. By accentuating the importance of proactive security, this research endeavors to establish a foundational approach to cyber-physical systems security and resiliency. It recognizes the evolving nature of cyber-physical systems and the specific security challenges facing each system in today's hyper-connected world and hence focuses on a single case study. </p>
53

Fuzz testování REST API / Fuzz Testing of REST API

Segedy, Patrik January 2020 (has links)
Táto práca sa zaoberá fuzz testovaním REST API. Po prezentovaní prehľadu techník používaných pri fuzz testovaní a posúdení aktuálnych nástrojov a výskumu zameraného na REST API fuzz testovanie, sme pristúpili k návrhu a implementácii nášho REST API fuzzeru. Základom nášho riešenia je odvodzovanie závislostí z OpenAPI formátu popisu REST API, umožňujúce stavové testovanie aplikácie. Náš fuzzer minimalizuje počet po sebe nasledujúcich 404 odpovedí od aplikácie a testuje aplikáciu viac do hĺbky. Problém prehľadávania dostupných stavov aplikácie je riešený pomocou usporiadania závislostí tak, aby sa maximalizovala pravdepodobnosť získania potrebných vstupných dát pre povinné parametre, v kombinácii s rozhodovaním, ktoré povinné parametre môžu využívať aj náhodne generované hodnoty. Implementácia je rozšírením Schemathesis projektu, ktorý generuje vstupy za pomoci Hypothesis knižnice. Implementovaný fuzzer je použitý na testovanie Red Hat Insights aplikácie, kde našiel 32 chýb, z čoho jednu chybu je možné reprodukovať len za pomoci stavového testovania.
54

Detecting Synchronisation Problems in Networked Lockstep Games / Upptäcka synkroniseringsproblem i nätverksuppkopplade lockstep-spel

Liljekvist, Hampus January 2016 (has links)
The complexity associated with development of networked video games creates a need for tools for verifying a consistent player experience. Some networked games achieve consistency through the lockstep protocol, which requires identical execution of sent commands for players to stay synchronised. In this project a method for testing networked multiplayer lockstep games for synchronisation problems related to nondeterministic behaviour is formulated and evaluated. An integrated fuzzing AI is constructed which tries to cause desynchronisation in the tested game and generate data for analysis using log files. Scripts are used for performing semi-automated test runs and parsing the data. The results show that the test system has potential for finding synchronisation problems if the fuzzing AI is used in conjunction with the regular AI in the tested game, but not for finding the origins of said problems. / Komplexiteten förenad med utveckling av nätverksuppkopplade dataspel skapar ett behov av verktyg för att verifiera en konsistent spelarupplevelse. Vissa nätverksspel hålls konsistenta med hjälp av lockstep-protokollet, vilket kräver identisk exekvering av skickade kommandon för att spelarna ska hållas synkroniserade. I detta projekt formuleras och evalueras en metod för att testa om nätverksuppkopplade flerspelarspel lider av synkroniseringsproblem relaterade till ickedeterministiskt beteende. En integrerad fuzzing-AI konstrueras som försöka orsaka desynkronisering i det testade spelet och generera data för analys med hjälp av loggfiler. Skript används för att utföra halvautomatiserade testkörningar och tolka data. Resultaten visar att testsystemet har potential för att hitta synkroniseringsproblem om fuzzing-AI:n används tillsammans med den vanliga AI:n i det testade spelet, men inte för att hitta de bakomliggande orsakerna till dessa problem.
55

Programming tools for intelligent systems

Considine, Breandan 04 1900 (has links)
Les outils de programmation sont des programmes informatiques qui aident les humains à programmer des ordinateurs. Les outils sont de toutes formes et tailles, par exemple les éditeurs, les compilateurs, les débogueurs et les profileurs. Chacun de ces outils facilite une tâche principale dans le flux de travail de programmation qui consomme des ressources cognitives lorsqu’il est effectué manuellement. Dans cette thèse, nous explorons plusieurs outils qui facilitent le processus de construction de systèmes intelligents et qui réduisent l’effort cognitif requis pour concevoir, développer, tester et déployer des systèmes logiciels intelligents. Tout d’abord, nous introduisons un environnement de développement intégré (EDI) pour la programmation d’applications Robot Operating System (ROS), appelé Hatchery (Chapter 2). Deuxièmement, nous décrivons Kotlin∇, un système de langage et de type pour la programmation différenciable, un paradigme émergent dans l’apprentissage automatique (Chapter 3). Troisièmement, nous proposons un nouvel algorithme pour tester automatiquement les programmes différenciables, en nous inspirant des techniques de tests contradictoires et métamorphiques (Chapter 4), et démontrons son efficacité empirique dans le cadre de la régression. Quatrièmement, nous explorons une infrastructure de conteneurs basée sur Docker, qui permet un déploiement reproductible des applications ROS sur la plateforme Duckietown (Chapter 5). Enfin, nous réfléchissons à l’état actuel des outils de programmation pour ces applications et spéculons à quoi pourrait ressembler la programmation de systèmes intelligents à l’avenir (Chapter 6). / Programming tools are computer programs which help humans program computers. Tools come in all shapes and forms, from editors and compilers to debuggers and profilers. Each of these tools facilitates a core task in the programming workflow which consumes cognitive resources when performed manually. In this thesis, we explore several tools that facilitate the process of building intelligent systems, and which reduce the cognitive effort required to design, develop, test and deploy intelligent software systems. First, we introduce an integrated development environment (IDE) for programming Robot Operating System (ROS) applications, called Hatchery (Chapter 2). Second, we describe Kotlin∇, a language and type system for differentiable programming, an emerging paradigm in machine learning (Chapter 3). Third, we propose a new algorithm for automatically testing differentiable programs, drawing inspiration from techniques in adversarial and metamorphic testing (Chapter 4), and demonstrate its empirical efficiency in the regression setting. Fourth, we explore a container infrastructure based on Docker, which enables reproducible deployment of ROS applications on the Duckietown platform (Chapter 5). Finally, we reflect on the current state of programming tools for these applications and speculate what intelligent systems programming might look like in the future (Chapter 6).

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