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Methods for optimization of digital signatures
Špidla, Aleš ; Hajný, Jan (referee) ; Malina, Lukáš (advisor)
The thesis briefly describes the digital signatures and basic methods (RSA, DSA, ECDSA) for the creation and verification of the digital signature. The method of group signatures designed by Boneh, Boyen and Shacham (BBS) is described in more details as well as the method designed by Bonen and Shacham (BS). The thesis further explores related issue of the implementation of batch signing and verification for the above mentioned methods and their practical application, particularly for systems Vehicular ad-hod network (VANET) and cloud storage in the field of forensic IT. The purpose of the thesis is to determine which of the methods BBS and BS is more suitable for these systems in terms of computational complexity. For this reason, the author created the program for the comparison of methods BBS and BS. The programme compares the time consumption of the methods for signing and verification of incoming messages. The results of the measurement are summarized in the conclusion along with the justification why the particular methods are suitable for the systems.
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Electronic geocaching
Průcha, Jan ; Strašil, Ivo (referee) ; Burda, Karel (advisor)
The master’s thesis is focusing on electronization of worldwide known game geocaching. It contains introduction to classic geocashing, analysis of current status and outline of possible solution. The design of electronization is based on smart card Gemalto. Very important part of the thesis is cryptographic security, therefore there is explanation of symetric and asymetric cryptography. The digital signature of transmitted message is realized by RSA algorithm, which is supported by the Gemalto smart card. Due to future expandability, it is appropriate to use general protocol. For this reason was chosen the ACP protocol which the supervisor of thesis adviced. In the following part, there is introduction to smart cards, their types and detailed description of Gemalto smart card. In the chapter 7 starts the solution of this issue and there are described the programmed apps.
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The use of artificial intelligence in cryptography
Lavický, Vojtěch ; Rosenberg, Martin (referee) ; Babnič, Patrik (advisor)
Goal of this thesis is to get familiar with problematics of neural networks and commonly used security protocols in cryptography. Theoretical part of the thesis is about neural networks theory and chooses best suitable type of neural network to use in cryptographic model. In practical part, a new type of security protocol is created, using chosen neural network.
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Electromagnetic analysis
Kolofík, Josef ; Reichert, Pavel (referee) ; Martinásek, Zdeněk (advisor)
This thesis deals with electromagnetic analysis and applications of electromagnetic side channel. The first and second part describes the basics of cryptography, function of cryptographic module and side-channel attacks. The third part discusses the electromagnetic analysis, construction of probe, a description of the laboratory workplace, the electromagnetic emission of PIC16F84A, AES and preparation for laboratory measurements. The fourth part describes specific laboratory measurements and extracting the useful signal. In the fifth part of the thesis presents the results of processing the measured values, the outputs generated by scripts and found the link between measured curves and AES encryption key. In the sixth part of the thesis are analyzed the basics of defense against side channel attack.
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Modern Asymmetric Cryptosystems
Walek, Vladislav ; Sobotka, Jiří (referee) ; Malina, Lukáš (advisor)
Asymmetric cryptography uses two keys for encryption public key and for decryption private key. The asymmetric cryptosystems include RSA, ElGamal, Elliptic Curves and others. Generally, asymmetric cryptography is mainly used for secure short messages and transmission encryption key for symmetric cryptography. The thesis deals with these systems and implements selected systems (RSA, ElGamal, McEliece, elliptic curves and NTRU) into the application. The application can test the features of chosen cryptosystems. These systems and their performance are compared and evaluated with the measured values. These results can predict the future usage of these systems in modern informatics systems.
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Cryptanalysis using neural networks
Budík, Lukáš ; Mačák, Jaromír (referee) ; Martinásek, Zdeněk (advisor)
This dissertation deals with analysis of current side canal by means of neural network. First part describes basis of cryptografy and dilemma of side canal. In the second part is theoretickly described neural network and correlative analysis. Third part describes practical analysis of calibres of current side canals by means of classifier which uses neural network in Matlab surrounding. This classifier is confronted with classifier which uses correlative analysis.
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Virtual serial port and its safety conversion to Ethernet
Pokorný, Michal ; Krajsa, Ondřej (referee) ; Koutný, Martin (advisor)
Bachelor´s thesis try to find a solution to make virtual serial port and its safe transfer on Ethernet. Nowdays communications channels don't offer appropriate security of a whole communication. Therefore it depends on get-togethers, in order to realize this security themselves.This means ensure reliable data transfer, these data from among get-togethers encrypt in order to appropriate attacher be unable to read them in real - time, eventually to change them. As a result this Bachelor thesis is the application, which, except transfer between virtual serial port and Ethernet, insure authentication among get - togehthers communication and cipher transfer among them. As an encryption algorithm is used algorithm AES. It is concerned symmetrical cipher, which ciphers data after pages about size 128 byte.
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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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Network attacks by Cain & Abel
Smékal, Lukáš ; Stančík, Peter (referee) ; Sobotka, Jiří (advisor)
This Master’s thesis is dealt in the local area network security, cryptographic algorithms, particular attacks on computer networks a practical application these attacks in local area networks. To application particular attacks is used the Cain & Abel program. The detailed manual for this program is created from the results of these attacks. This manual contains the exhibits of usage particular program tools and the attack application exhibits. This manual considers consequences of particular attacks and summarises achieved results during work with tools too. Master thesis closely deals with one of the program tools called RSA SecureID Token Calculator. Authentication via hardware tokens is contained in this Master thesis. Thesis contains the way of authentication using RSA SecureID Token Calculator without physical owning of the hardware token. Cain & Abel program shows and interprets why cashed passwords in operation system are dangerous and it shows methods how attacker can reveal this passwords from the operation system memory. This Master thesis is focused on sniffing credentials and passwords in local area networks and it is focused on cryptographic algorithms cracking for username and passwords revealing.
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Random number generator
Zouhar, Petr ; Martinásek, Zdeněk (referee) ; Sobotka, Jiří (advisor)
The thesis deals with issues of random numbers, their generating and use in cryptography. Introduction of work is aimed to resolution of random number generators and pseudo--random number generators. There is also included often used dividing generators on software and hardware. We mention advantages and disadvantages of each type and area of their use. Then we describe examples of random and pseudorandom numbers, mainly hardware based on physical phenomenon such as the decay of radioactive material or use atmospheric noise. The following part is devoted to suggestion own random number generator and a description of its functionality. In the second half of the work we devote to the field of cryptography. We know basic types of cryptographic systems, namely symmetric and asymmetric cryptosystems. We introduce a typical representant the various type and their properties. At the end of the work we again return to our random number generator and verify the randomness generated numbers and obtained cryptograms.
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