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Cryptography on Computationally Limited Devices
Hampl, Dalibor ; Hajný, Jan (referee) ; Malina, Lukáš (advisor)
The thesis focuses on cryptographic algorithms of low performance devices, and mutual authentication of authentication server and user using smart cards. In the first part of this thesis the cryptography, cryptographic primitives, cryptographic goals, security models and cryptographic algorithms of low performance devices are presented. The second part focuses on low performance devices as RFID tags, NFC technology, microcontrollers and smart cards (.NET cards, java cards, MIFARE cards). The practical part deals with the comparison of chosen low performance devices and measure the time required for encryption and decryption using different cryptographic algorithms on Gemalto .NET Smart Card V2+. This thesis describes and explains the three authentication schemes for mutual authentication of remote server and user using smart cards. The new authentication scheme, which is based on the second related scheme, attempts to eliminate possible security attacks and keeps efficiency. For all four authentication schemes the application is implemented to test required time for authentication of server and user using smart cards.
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Antivirus protection of a computer from a boot repository
Mlejnek, Jiří ; Malina, Lukáš (referee) ; Burda, Karel (advisor)
ABSTRACT Theme of the thesis is the design method of anti-virus protection with the use of an alternative boot store. Processed is a related issue of viruses and the possibility of defenses against them. This thesis is focused on the design and selection of components solutions enabling the execution of antivirus test from the undistorted by the operating system. With selected components continues to realize an alternative booting the operating system from a Windows platform computer network with automatic virus checking of all local disks. The results of inspection are transmitted using signed files on a network server and typically give an overview of the results of the individual tests.
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Multiaplication smart cards
Meluzín, Ivo ; Malina, Lukáš (referee) ; Sobotka, Jiří (advisor)
The goal of the first part of the thesis is to describe the options of wide usage of chip cards in different segments of our life. Consequently it is necessary to mention hardware and software equipment of smart card, its communication with terminal and data security. In this thesis we focus on Java Card environment in which we will try to create two applications, one for electronic purse and the second for user identification. Basically, we need to mention multiapplicational rules of sharing data and objects. At the end of the thesis we are focusing on the possibility of mutual interference between the applications and on protection against attacks. Also future applications of this technology are described.
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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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Efficient Digital Signature Schemes
Varga, Ondrej ; Sobotka, Jiří (referee) ; Malina, Lukáš (advisor)
Digital signatures, which take the properties of classical signatures, are used to secure the actual content of documents, which can be modified during transmission over an insecure channel. The problems of security and protection of communicating participants are solved by cryptographic techniques. Identity verification, message integrity, credibility, the ownership of documents, and the secure transmission of information over an unsecured channel, are all dealt with in secure communications - Public Key Infrastructure, which uses digital signatures. Nowadays digital signatures are often used to secure data in communication over an unsecured channel. The aim of the following master’s thesis is to familiarize readers with the necessary technological aspects of digital signatures, as well as their advantages and disadvantages. By the time digital signatures are being used they will have to be improved and modified to be secure against more sophisticated attacks. In this paper, proposals of new efficient digital signature schemes and their comparison with current ones are described. Also are examined their implications for computationally weak devices, or deployment in low speed channel transmission systems. After an explanation of cryptography and a description of its basic subjects, digital signatures are introduced. The first chapter describes the possible formatting and architecture of the digital signature. The second part of this master’s thesis is about current digital signature schemes and their properties. Chapter 3 describes some proposals of new efficient digital signature schemes and their comparison to those currently in use. In the practical part, the implementations (in the environment .NET in C#) of two effective digital signature schemes as part of a client-server application are presented and described (Chapter 4). In the last chapter the comparison and analysis of the implemented signature schemes are provided.
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Remote Client Security
Friedberg, Jiří ; Karásek, Jan (referee) ; Malina, Lukáš (advisor)
This master’s thesis is devoted to safe operating remote station. The security of data and electronic services is very important nowadays because the number of attacks to computer networks is increasing. The security of network services and information can be provided in several different ways which can be combined. The basic security mechanisms are authentication and data encryption. Both these methods are included to the implementation of operating remote station which is the main part of this work. The user of the resulting application will have a choice from several methods of authentication and data encryption. Whole traffic is encryption from the transfer of view of remote desktop to the transfer of files. Safety factor depends only up to the user consequently on that what type of authentication and encryption the user choose. The thesis also deals with analysis of implemented safely functions. Brings the results of analysis of effect of encryption algorithms to data connection of remote desktop.
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Anonymous communication in Internet environment
Pajtinová, Mária ; Malina, Lukáš (referee) ; Hajný, Jan (advisor)
Master´s thesis focuses on certain possibilities of how user can anonymously commununicate through the Internet. There are described following anonymous programs: TOR, JAP, I2P and CyberGhost, which allow user to hide his own identity to other IP address. Subsequently, measurements from different technologies are made by anonymous program TOR for calculate transmission speed.
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Modern computer viruses
Malina, Lukáš ; Malý, Jan (referee) ; Pust, Radim (advisor)
Bachelor’s thesis “Modern computer’s viruses” is composed from two mainly object (analysis computer’s viruses and suggestion of security middle computer network), separated for three parts: Analysis computer’s viruses, Personal suggestion of security personal computer end-user (computer terminal) and Personal suggestion of security middle computer network. Methods of transmission and infection, specific properties of viruses and impact upon personal computers are examined in the first part. Resolution of personal suggestion of security personal computer with help of antivirus software, personal firewall and antispam software is inducted in the second part. Futher, results of testing some free AV software and other security software are summarized with possible progress of configuration and recommendation for correct running this software. Complex suggestion of security middle computer network is adduced in the third part, where is inducted structure of security network. Configuration progression and recommendation for maximum security is indicated on particular used components. Structure is adapted for active network Cisco components, which are most used around these days. Completely suggestion of security network is directed on hardware firewall Cisco PIX, where is unfolded potential possibility of options. Futher, the third part contain some important tips and recommendation for completely working network, including setting security preference, security passwords and data encryption. Also, there is described various techniques monitoring and supervision working security network using complex monitoring software MARS (Cisco security monitoring, analyzing and response system) from Cisco company.
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Internet privacy protection
Malina, Lukáš ; Doležel, Radek (referee) ; Hajný, Jan (advisor)
Anonymous authentication is a mean of authorizing a user without leakage of user personal information. The technology of Anonymous Authentication Systems (AAS) provides privacy of the user and yet preserves the security of the system. This thesis presents the basic cryptographic primitives, which can provide anonymous authentication. Among these primitives there are usually some asymmetric cryptosystems, but an essential part of anonymous authentication is based on zero knowledge protocols, blind signature schemes, threshold group schemes, etc., that are presented in Chapter 1. Generally, Anonymous Authentication Systems have application as electronic coin, electronic cash, group signatures, anonymous access systems, electronic vote, etc., which are analyzed and presented in Chapters 2 and 3. In the practical section, the implementation (in the environment .NET in C#) of the AAS system is presented and described in Chapter 4, which is being developed at the FEEC BUT.
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Influence of aroma active compounds on flavour of fruit yogurts
Malina, Lukáš ; Babák, Libor (referee) ; Vítová, Eva (advisor)
This diploma thesis deals with the determination of aroma compounds in fruit yoghurts. These compounds are crucial for flavour of these dairy products. Two types of fruit yoghurts were analyzed, creamy (8 % of fat) and light (less than 0,1 % of fat), with various fruit ingredients, produced in dairy Mlékárna Valašské Meziříčí, spol. s r.o. Analysis was carried out by gas chromatography with extraction of analytes by SPME - solid phase microextraction. Six groups of different aromatic compounds such as ketones, aldehydes, organic acids and their salts, alcohols and sulfides in different amounts were determined. These compounds have mostly microbiological origin (Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus are dairy yoghurt cultures usually used for yoghurt production), less amounts are present in cow's milk or in dairy additives. Yoghurts were simultaneously sensory evaluated using ranking test, scale test and pair test for determination of acceptability and flavour. The assessors were students and staffs faculty of chemistry VUT.
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