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Digital signature
Vaverka, Aleš ; Lambertová, Petra (referee) ; Zeman, Václav (advisor)
Digital signature, the subject of this semester paper, is nowadays very up-to-date. The still rising capabilities of the internet and the vision of lowering the amounts of paper documentation made it necessary to develop a way of signing documents which are transferred through the internet. This is supposed to be equally safe and unassailable as the handwritten signature. This method is called the digital signature. The paper focuses on the explanation of the essential terms connected to digital signature, such as certificate, certification authority, authentication, but in particular on the elementary cryption algorithms, further on applications that make use of digital signature, e.g. post services and electronic banking. In the final chapter, the positive and negative aspects of the electronic signature are discussed.
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NiCd, NiMH and Li-ion accumulator charger supplied and controlled via USB
Nosek, Petr ; Mišurec, Jiří (referee) ; Zeman, Václav (advisor)
Deals with analysis and battery charging NiCd, NiMH, Li-Ion through a series of microcontroller from Atmel AVR controlled and powered from a PC via USB. Part is devoted to the characteristics of the USB interface and software capabilities to the enumeration AVR microcontroller. It also contains the basic characteristics of charged batteries, including the known methods of charging. The second half of the tehesis then provides a complete design and implementation of battery chargers, which consists of electronic parts, ATMEGA168 microcontroller program and the program for the PC. Presents circuit diagram of the charger and flowcharts of the main features of the program. The result of this thesis is functional battery charger above types. Attachments include a proposal DPS, a full circuit diagram and the charge and discharge characteristics of cells. The thesis is also referred to annex to the optical disk. Here it is mainly programs for microcontroller and PC. They are listed here as well as individual projects for AVR Studio, Borland Builder C + + and Eagle, which was created by chargers.
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Adjustable source supplied and controlled via USB
Pavlíček, Petr ; Daněček, Vít (referee) ; Zeman, Václav (advisor)
Master’s thesis deals with design and realization of power supply, which is supplied and controlled via USB bus. In theoretical part there are described principles of USB communication drivers which ensures this communication, there are described principles of linear voltage regulators and basic types of DC/DC converters. Mentioned is also PID regulator theory. Practical part aims for design of suitable DC/DC converter topology and creating algorithms for driving this converter. Next there is created PC program which drives power supply and there are also accomplished basic power supply measurements. The result of this thesis is functional power supply supplemented with PCB.
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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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Antierror systems with interleaving
Pacher, Jakub ; Zeman, Václav (referee) ; Němec, Karel (advisor)
This work involves in anti-error coding systems with interleaving. At first is given summary of high-frequency use error correction codes. Below there are described two basic techniques of interleaving and their confrontation. The next text is focusing on survey and characteristics of codes which conform to submission. After selection of optimal system is verified its function in MATLAB environment. Final step is creation of functional application in C++ environment. This application serves to transmission of error correction BMP pictures.
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Methods for the measurement of bit rates in data networks
Franc, Jan ; Martinásek, Zdeněk (referee) ; Zeman, Václav (advisor)
The target of this master's thesis were the known methods for testing the quality of transfer parameters of data networks. I have studied the RFC 2544 document to analyze these tests. From that information and by studying other existing web-based applications I was able to design a concept of my own application that will allow to measure basic quality parameters of transfers made through the Internet (the parameters: downstream, upstream, latency, variance of these and a traced route). My application doesn't require any modifications on the user's system. It's built on the server-based programming language PHP and uses the relational database engine MySQL to store measurement and user data. On the client side, it's assisted by the JavaScript scripting language. Both registered users and visitors are allowed to perform the listed measurements. Registered users are able to browse the history of their own benchmark results and also to send messages to others. There is an administrative account to oversee the operations. Another part of my thesis work is an application for Windows that performs the same measurements but does not use JavaScript.
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Comparison of HomePlug broadband systems and DS2 technology PLC
Horáček, Lukáš ; Zeman, Václav (referee) ; Mišurec, Jiří (advisor)
This thesis comparing broadband systems HomePlug and DS2 PLC technology (Power Line Communications). PLC is a technology for transmitting data over electrical power distribution network. The theoretical part consists of describing a system for broadband data communication over high-tension lines, the selection criteria, a description of DS2 and HomePlug (variants of chips, version, network architecture, elements). There are also described modulation techniques, interference, standards, standard ISO 50065 and access methods. The practical part consists of laboratory measurements with both systems. For the testing were used DS2 modems from the company Defidev and HomePlug modems from AirLive. These are then compared according to selected criteria.
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Software support for cryptography system training based on discrete logarithm
Kříž, Jiří ; Zeman, Václav (referee) ; Burda, Karel (advisor)
Current needs of human communication came to status, when most of transferred messages are considered as private and transition over non-secured communication lines in open form is not possible. That originated a lot of different methods for securing of messages and transfers in ciphered form. Two mainstreams were established, symmetric cryptography and asymmetric cryptography. Second of mentioned groups is based on usage of two information – keys, when one of then is broadly known and is public and second, well protected and private. Using a public key it is possible to establish a cryptogram of message, but for deciphering it is necessary to know private key. Asymmetric methods are based on mathematical problems, for which there is not an effective computing algorithm. This thesis are focused for asymmetric cryptosystems based on discrete logarithm problem, where ciphering of message using public key is very easy and quick, but deciphering without knowledge of private key is extremely time consuming process. Work describes a mathematical base of discrete logarithm problem, its’ properties and methods developed for solving of this problem. Descriptions of particular cryptosystems are given, i.e. ElGamal cryptosystem, Diffie-Hellman protocol and DSA. Second part of thesis is focused for web application developed as study support of discrete logarithm problem and of cryptosystems using this problem. It describes functional and graphical interface, work with it and options given to user working with application. Mentions also lessons for user which should help with understanding of described problems and practicing.
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Education application for Internet environment
Kratochvíl, Peter ; Škorpil, Vladislav (referee) ; Zeman, Václav (advisor)
This Master‘s thesis is dealing with the usage possibility of education application for internet environment in learning process. Nowadays, this kind of applications is called the E-learning system. Theoretical part is focused on basic principles, describes the reasons why are these systems so popular and used world wide. Negatives and positives of both, the e-learning system as well as the classic form of studying are described. Content of this part also shows the usual usage cases. Practical part deals with construction of the particular system, based on requested features. The main system was divided into the two main logical parts. Their functionality is well described. In this part also all used programming languages as well as tools and server operation systems are mentioned. Practical part is also used to show information about database system and description of the particular database which was created. In the conclusion can reader find the summary of all practical and theoretical results achieved during the work on the project.
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Design of security infrastructure for electronic archive
Doležel, Radek ; Lattenberg, Ivo (referee) ; Zeman, Václav (advisor)
This master's thesis deals with design of security infrastructure for electronic archive. In theoretical part is disscus about technical resources which are based on security services and protocols and methods which are used for protection. On basics of theoretical part is designed model of security infrastructure and it is built in laboratory. Model of security infrastructure is based on Open Source Software and as safety storages for private user authentication data are used cryptographic USB tokens. This master's thesis includes design and construction of real infrastructure of secured electronic archive. In each part of master's thesis is put main emphases on security and clear explanation from the beginning of desing of model of security infrastructure for electronic archive to finish of construction.
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