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Face Anti-Spoofing with Out-of-distribution Detection
Češka, Petr ; Vaško, Marek (referee) ; Špaňhel, Jakub (advisor)
This thesis aims to improve the accuracy of Vision Transformer-based face anti-spoofing models in detecting presentation attacks. The thesis uses out-of-distribution detection to filter out images that are too different from the training data, referred to as in-distribution. It examines how successful different methods are in identifying different data distributions, and how the filtering of out-of-distribution data based on these methods affects the accuracy of the model. Using the relative Mahalanobis distance, an AUROC of 97.6% can be achieved when distinguishing between in-distribution and out-of-distribution data. Filtering out images that should not be classified increases the accuracy of all tested models to over 99.9%. This can provide an additional layer of security for applications against face spoofing attacks.
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Liveness Detection on Fingers Using Vein Pattern
Dohnálek, Tomáš ; Váňa, Jan (referee) ; Drahanský, Martin (advisor)
Tato práce se zabývá rozšířením snímače otisků prstů Touchless Biometric Systems 3D-Enroll o jednotku detekce živosti prstu na základě žil. Bylo navrhnuto a zkonstruováno hardwarové řešení s využitím infračervených diod. Navržené softwarové řešení pracuje ve dvou různých režimech: detekce živosti na základě texturních příznaků a verifikace uživatelů na základě porovnávání žilních vzorů. Datový soubor obsahující přes 1100 snímků jak živých prstů tak jejich falsifikátů vznikl jako součást této práce a výkonnost obou zmíněných režimů byla vyhodnocena na tomto datovém souboru. Na závěr byly navrhnuty materiály vhodné k výrobě falsifikátů otisků prstů umožňující oklamání detekce živosti pomocí žilních vzorů.
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Penetration Tests of Speaker Verification System
Nguyen, QuangTrang ; Rohdin, Johan Andréas (referee) ; Plchot, Oldřich (advisor)
The aim of this bachelor thesis is to create a penetration tests of speaker verification system with the use of the speech synthesis method. This work studies methods of spoofing against automatic speaker verification system. Before designing of the test set, the system and it's components that were used in this work are described. The last chapters of this work include a description of the process of designing the test set, realization of the designed test and the last part contains evaluation of the results and answers the question if it is possible to penetrate a verification system with the use of speech synthesis.
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System for testing the robustness of communication unit LAN of remote data acquisition
Mlýnek, Petr ; Zeman, Václav (referee) ; Mišurec, Jiří (advisor)
Remote data collection systems are widely used. One of the area is also data collection in energetics, where the energy consumption can be collected daily and presented to users on-line. The advantage of the remote data collection is possibility of frequent readings without a physical presence at the electrometers. The data transmission over the Internet can be subject of various attacks, which is the disadvantage. The understanding of attack method is the most important thing. The protection against the hackers is not complicated, but requires lot of attention. This master's thesis is focused on testing security of the communication unit LAN of remote data acquisition against attacks from the Internet. The next aim of this thesis is to describe algorithm of particular attack, needed recourses for their realization and method of their measurement and evaluation. Communication unit and component composition for attacks simulation is described in the first part of this thesis. The next part is focused on scanning for hosts and ports. The main part of this thesis is focused on the denial of service attacks and man in the middle attacks. In the end of my thesis is described selection of cryptographic system for remote data acquisition and is showed possibility of authentication mirroring. Problems of physical security are described too. The result of this thesis is script implementing all attacks, which are described.
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Automatic Testing of JavaScript Restrictor Project
Bednář, Martin ; Pluskal, Jan (referee) ; Polčák, Libor (advisor)
The aim of the thesis was to design, implement and evaluate the results of automatic tests for the JavaScript Restrictor project, which is being developed as a web browser extension. The tests are divided into three levels - unit, integration, and system. The Unit Tests verify the behavior of individual features, the Integration Tests verify the correct wrapping of browser API endpoints, and the System Tests check that the extension does not suppress the desired functionality of web pages. The System Tests are implemented for parallel execution in a distributed environment which has succeeded in achieving an almost directly proportional reduction in time with respect to the number of the tested nodes. The benefit of this work is detection of previously unknown errors in the JavaScript Restrictor extension and provision of the necessary information that allowed to fix some of the detected bugs.
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Analysis and Demonstration of Selected Network Attacks
Jirásek, Jakub ; Trchalík, Roman (referee) ; Očenášek, Pavel (advisor)
The aim of this Bachelor thesis is to describe and realize selected network attacks which are taught at the FIT, Brno University of Technology. The thesis includes demonstration exercises that can be used for teaching computer network security. First part of this work discusses theory for each attack and possible security solutions. In the second part the practical realizations (for each network attack) are described.
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Non-Parallel Voice Conversion
Brukner, Jan ; Plchot, Oldřich (referee) ; Černocký, Jan (advisor)
Cílem konverze hlasu (voice conversion, VC) je převést hlas zdrojového řečníka na hlas cílového řečníka. Technika je populární je u vtipných internetových videí, ale má také řadu seriózních využití, jako je dabování audiovizuálního materiálu a anonymizace hlasu (například pro ochranu svědků). Vzhledem k tomu, že může sloužit pro spoofing systémů identifikace hlasu, je také důležitým nástrojem pro vývoj detektorů spoofingu a protiopatření. Modely VC byly dříve trénovány převážně na paralelních (tj. dva řečníci čtou stejný text) a na vysoce kvalitních audio materiálech. Cílem této práce bylo prozkoumat vývoj VC na neparalelních datech a na signálech nízké kvality, zejména z veřejně dostupné databáze VoxCeleb. Práce vychází z moderní architektury AutoVC definované Qianem et al. Je založena na neurálních autoenkodérech, jejichž cílem je oddělit informace o obsahu a řečníkovi do samostatných nízkodimenzionýálních vektorových reprezentací (embeddingů). Cílová řeč se potom získá nahrazením embeddingu zdrojového řečníka embeddingem cílového řečníka. Qianova architektura byla vylepšena pro zpracování audio nízké kvality experimentováním s různými embeddingy řečníků (d-vektory vs. x-vektory), zavedením klasifikátoru řečníka z obsahových embeddingů v adversariálním schématu trénování neuronových sítí a laděním velikosti obsahového embeddingu tak, že jsme definovali informační bottle-neck v příslušné neuronové síti. Definovali jsme také další adversariální architekturu, která porovnává původní obsahové embeddingy s embeddingy získanými ze zkonvertované řeči. Výsledky experimentů prokazují, že neparalelní VC na nekvalitních datech je skutečně možná. Výsledná audia nebyla tak kvalitní případě hi fi vstupů, ale výsledky ověření řečníků po spoofingu výsledným systémem jasně ukázaly posun hlasových charakteristik směrem k cílovým řečníkům.
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Enterprise Network IPS Security
Jakab, Vojtěch ; Babnič, Patrik (referee) ; Červenka, Vladimír (advisor)
This bachelor's thesis addresses the local area network security. The scope of this thesis is to explore the possibilities of security of these networks and introduction of some attacks which can threaten these networks. The main goal, however, is to design maximum security measures of testing network. CISCO router and Fortinet's firewall are available. Their configuration is limited by possibilities of their operating systems. By the appropriate programms the configuration of IPS configured on firewall is examined and they are used to try to evade this component. The last part of this work deals with executing particular network attacks. They are alaysed and agains successful attacks are proposed apropriate countermeasures.
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Penetration testing of ANC
Dušek, Jakub ; Jakub,, Přibyl (referee) ; Sedlák, Petr (advisor)
This diploma thesis deals with the evaluation of a security solution that was recently deployed by a British company renting office space. This validation system is based on a database of MAC addresses, a database of clients and active filtering of connected devices. The first part explains the concepts of computer network, VLAN and basic concepts needed to understand the function of dynamic assignment of VLAN and IP addresses. The second part is devoted to measurements based on hypotheses, according to which measures are proposed in the last part to solve these security problems.
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Interception of Modern Encrypted Protocols
Marček, Ján ; Korček, Pavol (referee) ; Kajan, Michal (advisor)
This thesis deals with the introduction to the security mechanism.The procedure explains the basic concepts, principles of cryptography and security of modern protocols and basic principles that are used for information transmission network. The work also describes the most common types of attacks targeting the eavesdropping of communication. The result is a design of the eavesdropping and the implementation of an attack on the secure communication of the SSL protocol..The attacker uses a false certificate and attacks based on poisoning the ARP and DNS tables for this purpose. The thesis discusses the principles of the SSL protocol and methodology of attacks on the ARP and DNS tables.
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