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Linear Cryptoanalysis
Kopko, Jan ; Hanáček, Petr (referee) ; Cvrček, Daniel (advisor)
This paper discusses one of possible attacks on block ciphers - linear cryptanalysis. In the beginning of this paper a basic structure of block cipher is presented, as well as concrete cipher on which the linear cryptanalysis is presented. After that basic principles of linear cryptanalysis and a preview of attack on this cipher follow.
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AES Tolerance to Timing Analysis
Ondruš, Juraj ; Matyáš, Václav (referee) ; Cvrček, Daniel (advisor)
This thesis deals with timing analysis of the AES (Advanced Encryption Standard). The design of {\em Rijndael\/}, which is the AES algorithm, is described here. For the side channel attacks is necessary to know the principles of the cache memory in CPU and its architecture. In this thesis are involved major security problems of AES which can be used for successful attacks. Several different implementations of AES are discussed too. Several types of timing attaks are also described. According to the experimentations these attacks should be efficient to the most presently used AES implementations. Finally, the results of this work are described, possible countermeasures against this attack and motions for the next research.
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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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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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Power side channel
Zapletal, Ondřej ; Mácha, Tomáš (referee) ; Martinásek, Zdeněk (advisor)
This thesis deals with side-channel cryptoanalysis. It is focused on power side-channel attack on cryptographic device. The microcontroller PIC is used as the cryptographic device. This microcontroller performs encryption through the symmetrical algorithm AES. For the purpose of simple and differential power analysis, we designed and constructed an experimental printed circuit board. The power consumption of the microcontroller PIC working with instruction AddRoundKey and SubBytes was scanned by a Tektronix CT-6 current probe. Data obtained by measuring were processed on the computer with relevant software and provided important information about the encryption key that was used.
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Security Analysis of Mifare Classic Smart Cards
Bobčík, Martin ; Hellebrandt, Lukáš (referee) ; Hujňák, Ondřej (advisor)
Goal of this bachelor thesis is a security study of MIFARE Classic contactless smart cards and risk analysis of their usage. There are described individual vunerabilities in the design and CRYPTO1 cipher of such cards. In this thesis is also experimented with Chameleon Mini device, which is used to perform two attacks and one cryptoanalysis of the cards. Namely, card emulation, relay attack, and analysis of insufficient randomness of cards' pseudorandom number generator. From those, only card emulation was fully successful.
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Library of Algorithms for Text Ciphering
Mikulka, Jiří ; Havel, Jiří (referee) ; Kubíček, Radek (advisor)
This thesis brings an overview of historical and modern methods and approaches used in cryptography. It also describes and assesses ciphers, which have been used since the very beginning of encryption till modern ciphers. Based on information resulting from this overview the reader should be able to distinguish between ciphers, know their advantages and disadvantages, and be able to choose the best cipher for any purpose. Ciphers mentioned in this thesis are implemented in a library called CipherLib , which shows usage of every described cipher.
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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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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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Safe Cryptography Algorithms
Mahdal, Jakub ; Hanáček, Petr (referee) ; Chmelař, Petr (advisor)
This thesis brings a reader an overview about historical and modern world of cryptographic methods, as well evaluates actual state of cryptographic algorithm progressions, which are used in applications nowadays. The aim of the work describes common symmetric, asymmetric encryption methods, cryptographic hash functions and as well pseudorandom number generators, authentication protocols and protocols for building VPNs. This document also shows the basics of the successful modern cryptanalysis and reveals algorithms that shouldn't be used and which algorithms are vulnerable. The reader will be also recommended an overview of cryptographic algorithms that are expected to stay safe in the future.
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