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Covering sets in steganography
Vacek, Jan ; Holub, Štěpán (advisor) ; Hojsík, Michal (referee)
Steganography is a science which is interested in communication hiding. This work is focused on the most recent methods related to this topic. Mainly, it is matrix embedding, which uses coding theory, and sum and difference covering sets (SDCS). Rainbow coloring of grid graphs is used to receive even better results. This technique decrease amplitude of performed changes. It makes stegosystems less likely to be detected. Properties which describe behavior of each stegosystem are included for each technique. 1
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Methods of steganography
Obdržálková, Karolína ; Blažek, Petr (referee) ; Člupek, Vlastimil (advisor)
This bachelor thesis deals with steganography, its types and methods. Steganography is generally described in this work. A significant part of this thesis is devoted to the development of steganography and also describes how is steganography used for malware and copyright protection. The next part describes the types of steganography according to the type of carrier, their methods and properties of steganographic methods. Based on theoretical knowledge, an application with a graphical user interface was created to hide and reveal secret information using steganographic method LSB. This application is described in the final part together with the evaluation of security of hidden information.
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Digital Steganalysis
Molnár, Ondřej ; Nevoral, Jan (referee) ; Strnadel, Josef (advisor)
Steganalysis is the opposite science discipline of the steganography - which is an art of information hiding . Steganography deals with embedding of secret messages to different types of media. The most commonly used cover media in modern steganography are image files . This bachelor's thesis creates an overview of known steganograpy and steganalysis methods . It also describes practical implementation of application that is able to detect hidden information in image.
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Digital Image Steganography
Kolarčík, Tomáš ; Šimek, Václav (referee) ; Strnadel, Josef (advisor)
This bachelor thesis deals with digital image steganography and implements some of the available methods. This thesis describes steganography on a general level, it's history and it's current form. It also shows it's classification according to the type of carrier, the classification of the methods according to the style of hiding data and the influence of the hidden information. The primary subject of this thesis is image steganography, where facts that allow imperceptibly hide data inside image are described. A great part of this thesis is dedicated to the characteristics of the methods, which we observe and to the methods themselves. All of the methods described are implemented in a graphical and console application. The created application provides multiple image formats for hiding. In the last part, testing is performed in terms of capacity, imperceptibility and robustness.
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Digital Text Steganography
Nodžák, Petr ; Nevoral, Jan (referee) ; Strnadel, Josef (advisor)
The goal of this bachelor project was to learn about digital text steganography, about methods for hiding the text, to implement my own or already existing methods and finally to compare acomplished results of these methods. This project introduces four methods (Zero distribution, semathics, syntax and Format based) which hide secret data into cover text, each of them by its own way. Research has found that semanthics method produces the best properties of stego text followed by Format based and Zero distribution, syntax method ended up worst. Based on the data found we can choose which method we will use.
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Digital Steganography for Executables
Tobiáš, Pavel ; Bidlo, Michal (referee) ; Strnadel, Josef (advisor)
This bachelor's thesis concerns itself with steganographic concealment of arbitrary data in executable files . Initially it speaks in general terms , mainly about injection - and substitution - based steganographic methods for various types of cover - objects . Afterwards , the focus is on executable files in the ELF format and the x86 ISA family ; permutation - based methods for instructions and basic block chains are mentioned and the substitution - based method of instruction equivalence classes is examined . Consequently , the design, implementation , testing and optimization of a custom solution based on the last mentioned method are described . Finally , the methods and outcomes of experimenting with the custom solution are described .
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Digital Image Steganography
Mazánek, Antonín ; Šimek, Václav (referee) ; Strnadel, Josef (advisor)
This bachelor's thesis introduces the steganography scientific discipline. It presents its ancient and relative recent history, mentions its current use and outlines the possible directions for steganography future. It introduces steganography into context of hiding information superior domain and highlights differences between other methods in this domain. It describes steganography subdivisions and closer deals with digital image steganography. It presents some known methods and types of digital image data. The thesis also contains more detailed description of image data in PNG format. It describes the implementation of LSB and PVD steganography methods with images in PNG format as cover object and evaluates their key properties, namely: imperceptibility, capacity and robustness. At the end of the thesis, the author's reflection on the results and possibilities of further modifications of the mentioned methods is given.
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Digital Audio Steganography
Morávek, Jan ; Šimek, Václav (referee) ; Strnadel, Josef (advisor)
Nowadays much more information is transfered and saved in electronic files. The digitalization allows easier access to information, not only for the user, but also for a possible attacker. This fact leads to progress in information security area. Besides cryptography, this also includes steganography. This thesis is focused on steganography in general and describes digital audio steganography in detail. Implementation and evaluation of several methods are also parts of this thesis.
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Lego Technic encryption demonstrator
Jančík, Jakub ; Malina, Lukáš (referee) ; Hajný, Jan (advisor)
The bachelor thesis is mostly about mechanical encryption. Primary task was to build demonstrator encryptor using only LEGO Technic building kit, which would allow polyalphabetical substitution encryption. The theoretical part includes information about origins of steganography, cryptography and cryptanalysis, it explains the process of the polyalphabetical substitution encryption and it will introduce Enigma – how it went on during development, on what principle it works and thanks to what it stopped being safe. Device was extended with LEGO MINDSTORMS which allowed to build the Enigma demonstrator.
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Environment for Lifting
Kubový, Jan ; Pelikán, Josef (advisor) ; Lokoč, Jakub (referee)
The aim of the thesis is to create a library that will provide ease way to cre- ating and experimenting with computing networks. The concpet of computing netowork can be explained as algorithms whitch can be devided into small simple parts (nodes). The main focus of this library is to easily experiment with trans- formations based on lifting. There are inverse operations for these connections, which are used for lossless compression of data or signal. Emphasis was put on the simplicity of creating new nodes and subsequent connections. An integral part of the work is also an example of several transformations based on lifting.
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