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Cryptographic methods of data security
Miloš, Jiří ; Koutný, Martin (referee) ; Lambertová, Petra (advisor)
Bachelor‘s thesis on theme Cryptographic methods of data security consists of three parts. In first part are itemized general theoretical principles, which employs in these sphere. There are also mentioned not only contemporaneous but historical cryptographic standards or algorithms. The second part of these bachelor‘s thesis refer to a possibility of breaking these standards. There are described most applied cryptoanalytics principes and their practical using, especially in the sphere of computer networks and their services. The final part contains a description of the development of simple computer application, which demonstrates the use cryptographic methods in the security packages in personal computer.
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Distributed systems for cryptoanalysis
Vašek, Jiří ; Trzos, Michal (referee) ; Sobotka, Jiří (advisor)
This thesis should introduce a reader with basic objectives of parallel computing followed by distributed systems. The thesis is also aimed at description of cryptographic attacks. The main point should be to obtain theoretic information for design of distributed system for cryptoanalysis.
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Modern cryptanalysis
Petřík, Tomáš ; Morávek, Patrik (referee) ; Martinásek, Zdeněk (advisor)
Issues of this thesis are focused on side-channel cryptanalysis. Particularly attention is paid to differential power analysis, when is simulated an attack on the cryptographic module for different conditions and for different structural features of this module. As the cryptographic module is used a PIC microcontroller, which is operating with AES symmetric encryption algorithm. For this purpose, a design of experimental printed circuit board was created. Then, this PCB was equipped only with the necessary components for the function of the cryptographic module. Cryptanalysis is aimed on current consumption of crypto module that is caused by execution of AddRoundKey instructions. Power consumption of PIC microcontroller is measured in depending on the size of power supply voltage, size of serial resistor, size of bypass capacitor, and this thesis also examines the influence of ambient temperature on power consumption of PIC. The measured values are graphically presented and then discussed.
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Distributed systems for cryptoanalysys
Zelinka, Miloslav ; Martinásek, Zdeněk (referee) ; Sobotka, Jiří (advisor)
This work deals with crytpoanalysis, calculation performance and its distribution. It describes the methods of distributing the calculation performance for the needs of crypto analysis. Further it focuses on other methods allowing the speed increasing in breaking the cryptographic algorithms especially by means of the hash functions. The work explains the relatively new term of cloud computing and its consecutive use in cryptography. The examples of its practical utilisation follow. Also this work deals with possibility how to use grid computing for needs of cryptoanalysis. At last part of this work is system design using „cloud computing“ for breaking access password.
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Portal for the support of cryptography instruction
Forman, Tomáš ; Doležel, Radek (referee) ; Zeman, Václav (advisor)
The main goal of this master's thesis is building of web portal for presentation basic cryptography algorithms. Those algorithms would be explained in the theoretical page in the first place. After that, they would be demonstrated by scripts. One part of this project is designing simplified theoretical element for basic impletion portal of information. Next part is creating web portal by one of the free available CMS´s systems. Programming language JAVA would be used as an instrument for creating demonstration scripts. For creating animations will be used the Flash animation tool. Target of formed web portal is creating community of expert public. It would make new articles, scripts and knowledge. This way, the portal would be kept current. The section which would include failure the most widely used algorithms and instructions how to eliminate it will be part of portal.
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Side channel attacks
Popovský, Michal ; Sobotka, Jiří (referee) ; Martinásek, Zdeněk (advisor)
It is very difficult in real-time breaking the cryptographic algorithms used at present. The Classical cryptoanalysis is based on finding weaknesses in the mathematical structure of the algorithm. Discovery of side channels caused a substantial change in this science. Side-channel attacks are based on incorrect physical implementation of cryptographic algorithms. This new way attack changes notions about cryptography and security of systems. This master´s thesis contains a detailed description of the whole problem of side channels and deals with side-channel attacks on the RSA asymmetric algorithm. This thesis includes the design and realization of laboratory exercise, which is focused on the time attack on the RSA algorithm implementation.
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Design of hardware cipher module
Bayer, Tomáš ; Stančík, Peter (referee) ; Sobotka, Jiří (advisor)
This diploma’s thesis discourses the cryptographic systems and ciphers, whose function, usage and practical implementation are analysed. In the first chapter basic cryptographic terms, symmetric and asymetric cryptographic algorithms and are mentioned. Also usage and reliability are analysed. Following chapters mention substitution, transposition, block and stream ciphers, which are elementary for most cryptographic algorithms. There are also mentioned the modes, which the ciphers work in. In the fourth chapter are described the principles of some chosen cryptographic algorithms. The objective is to make clear the essence of the algorithms’ behavior. When describing some more difficult algorithms the block scheme is added. At the end of each algorithm’s description the example of practical usage is written. The chapter no. five discusses the hardware implementation. Hardware and software implementation is compared from the practical point of view. Several design instruments are described and different hardware design programming languages with their progress, advantages and disadvantages are mentioned. Chapter six discourses the hardware implementation design of chosen ciphers. Concretely the design of stream cipher with pseudo-random sequence generator is designed in VHDL and also in Matlab. As the second design was chosen the block cipher GOST, which was designed in VHDL too. Both designs were tested and verified and then the results were summarized.
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Software support for cryptography education
Stančík, Peter ; Vyoral, Josef (referee) ; Burda, Karel (advisor)
The main aim of this thesis was to study, choose and decribe techniques eligible for cryptography education. A pedagogically appropriate presentation for the selected techniques' principles was to be chosen. Another goal was to create an integrated modular web interface containing a calculator focused on cryptographic operations. The eligibility of techniques was assessed accordingly to the computing processes implied by these techniques and also accordingly to the ability of being presented in an illustrative way. A program simplifying calculations used in symetric and asymetric cryptography was designed and implemented. It disposes of a web interface and one of its parts is focused on steganographic techniques. On the other hand, any pedagogically appropriate presentation interconnecting this program with theoretical findings from this field was not found.
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Analysis of attacks on asymmetric cryptosystems
Tvaroh, Tomáš ; Ivánek, Jiří (advisor) ; Palovský, Radomír (referee)
This thesis analyzes various attacks on underlying computational problem of asymmetric cryptosystems. First part introduces two of the most used problems asymmetric cryptography is based on, which are integer factorization and computation of discrete logarithm. Algorithms for solving these problems are described and for each of them there is a discussion about when the use of this particular algorithm is appropriate and when it isn't. In the next part computational problems are related to algorithms RSA and ECC and it is shown, how solving the underlying problem enables us to crack the cypher. As a part of this thesis an application was developed that measures the efficiency of described attacks and by providing easy-to-understand enumeration of algorithm's steps it can be used to demonstrate how the attack works. Based on the results of performed analysis, most secure asymmetric cryptosystem is selected along with some recommendations regarding key pair generation.
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