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Securing narrowband wireless communication in licensed band
Kolaja, David ; Brychta, Josef (referee) ; Fujdiak, Radek (advisor)
Contemporary demand for mobile devices and development of devices in the Internet of Things is constantly increasing. This reality also raises concerns about security and privacy of ongoing communication. This is no exception for expanding scale of Low Powered Wide Area Network (LPWAN) devices which communicate over Narrowband IoT and the customer of such devices who has to rely on security of provider’s network to secure customer’s data. This security is effective only in operator’s network while there is no end-to-end encryption enabled. Therefore, this thesis deals with the analysis of NB-IoT communication and its possible end-to-end security proposal, which also provides elements of post-quantum algorithms. Last but not least, this thesis deals with application of this proposal on constrained device and evaluation of its effectivness of time, energy and memory demands.
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Post-quantum cryptography on constrained devices
Matula, Lukáš ; Dzurenda, Petr (referee) ; Malina, Lukáš (advisor)
In recent years, there has been a lot of technological development, which among other things, brings the designs and implementation of quantum computing. Using Shor’s algorithm for quantum computing, it is highly likely that the mathematical problems, which underlie the cryptographic systems, will be computed in polynomial time. Therefore, it is necessary to pay attention to the development of post-quantum cryptography, which is able to secure systems against quantum attacks. This work includes the summary and the comparison of different types of post-quantum cryptography, followed by measuring and analysing its levels of difficulty in order to implement them into limited devices, such as smart cards. The measured values on the PC are used to determine the most suitable implementation on the circuit card and then the verification method itself is implemented on it.
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Ensuring Long-term Data Integrity in Cloud Storage
Nohava, Martin ; Člupek, Vlastimil (referee) ; Malina, Lukáš (advisor)
The subject of the thesis is the design and development of a system to ensure the long-term integrity of data from the Nextcloud cloud storage, which manages and stores electronic evidence. In the introductory part, the terms and principles used for securing data integrity are presented, including quantum-resistant digital signature schemes. Subsequently, the architecture of the archiving system and the method of its connection with the Nextcloud cloud storage are proposed. The resulting system consists of two main components, the Archive application, which extends the web interface of the Nextcloud instance, and the archiving system, which ensures the integrity of the archived files themselves. In addition to time stamps, system also uses a quantum-resistant Dilithium signature scheme. At the end of the work, an evaluation of the implemented solution is carried out by measuring the performance of the archiving system, and options for its further development are proposed.
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Goppa codes and their applications
Kotil, Jaroslav ; Drápal, Aleš (advisor) ; Šťovíček, Jan (referee)
Title: Goppa codes and their applications Author: Bc. Jaroslav Kotil Department: Department of algebra Supervisor: prof. RNDr. Aleš Drápal, CSc., DSc. Abstract: In this diploma paper we introduce Goppa codes, describe their para- metres and inclusion in Alternant codes, which are residual Generalized Reed- Solomon codes, and Algebraic-geometry codes. Aftewards we demonstrate deco- ding of Goppa codes and introduce Wild Goppa codes. We also describe post- quantum cryptography member: McEliece cryptosystem for which no effective attacks with quantum computers are known. We outline a usage of this crypto- system with Goppa codes and describe the security of the cryptosystem together with possible attacks of which the most effective ones are based on information- set decoding. Keywords: Goppa codes, Generalized Reed-Solomon codes, Algebraic-geometry codes, Post-quantum cryptography, McEliece cryptosystem 1
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MQ problem
Středa, Adolf ; Žemlička, Jan (advisor) ; Šťovíček, Jan (referee)
The aim of this thesis is to describe a general MQ Problem with a focus on its variant called HFE, outline several attacks on a basic scheme based on HFE and describe a new attack on HFEz, a cryptosystem based on special polynomials over finite fields with a modification, which discards a portion of the output from the initial transformation. This ensures a dependency on more variables while keeping the same size of the field. The attack starts with a translation of HFE into HFE with branches, followed by a branch separating algorithm described in [Fel06]. The separation algorithm uses the public key to derive an operation, which induces (with addition) a non-associative algebra. Utilising some properties of non-associative algebras, a matrix, which can separate variables into distinct sets according to branches, is calculated. This leads to stripping off the HFEz modification and thus allowing us to attack directly the HFE polynomial. Powered by TCPDF (www.tcpdf.org)
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Post-quantum cryptography on constrained devices
Matula, Lukáš ; Dzurenda, Petr (referee) ; Malina, Lukáš (advisor)
In recent years, there has been a lot of technological development, which among other things, brings the designs and implementation of quantum computing. Using Shor’s algorithm for quantum computing, it is highly likely that the mathematical problems, which underlie the cryptographic systems, will be computed in polynomial time. Therefore, it is necessary to pay attention to the development of post-quantum cryptography, which is able to secure systems against quantum attacks. This work includes the summary and the comparison of different types of post-quantum cryptography, followed by measuring and analysing its levels of difficulty in order to implement them into limited devices, such as smart cards. The measured values on the PC are used to determine the most suitable implementation on the circuit card and then the verification method itself is implemented on it.
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Securing narrowband wireless communication in licensed band
Kolaja, David ; Brychta, Josef (referee) ; Fujdiak, Radek (advisor)
Contemporary demand for mobile devices and development of devices in the Internet of Things is constantly increasing. This reality also raises concerns about security and privacy of ongoing communication. This is no exception for expanding scale of Low Powered Wide Area Network (LPWAN) devices which communicate over Narrowband IoT and the customer of such devices who has to rely on security of provider’s network to secure customer’s data. This security is effective only in operator’s network while there is no end-to-end encryption enabled. Therefore, this thesis deals with the analysis of NB-IoT communication and its possible end-to-end security proposal, which also provides elements of post-quantum algorithms. Last but not least, this thesis deals with application of this proposal on constrained device and evaluation of its effectivness of time, energy and memory demands.
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A study on ``A New Public-Key Cryptosystem via Mersenne Numbers''
Richter, Filip ; Göloglu, Faruk (advisor) ; El Bashir, Robert (referee)
In 2016 NIST announced a start of a process of development and standardiza- tion of a post-quantum public-key encryption scheme. Mersenne-756839 was one of the proposals. This proposal is described in this thesis, as well as the known attacks against it. The description and the theoretical background behind these attacks are presented in a rigorous way and are accessible to the reader without any previous knowledge about the post-quantum cryptography. New additional ideas for the implementation of the attacks are also presented. Finally, these attacks are implemented and attached to the thesis. 1
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Comparing Groups of Public-Key Ciphers
Lukáš, Martin ; Ivánek, Jiří (advisor) ; Palovský, Radomír (referee)
In this thesis, I introduce several groups of public-key algorithms, the groups being factori-zation problem, discrete logarithm problem, and other problems. I choose one representa-tive algorithm from each group and describe it in-depth, also mentioning certain aspects used in real world implementations and most important attacks. other problems. The objec-tives of this thesis are to compare these groups as well as algorithms in them according to their operational speed, key lengths and resistance against quantum cryptanalysis.
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MQ problem
Středa, Adolf ; Žemlička, Jan (advisor) ; Šťovíček, Jan (referee)
The aim of this thesis is to describe a general MQ Problem with a focus on its variant called HFE, outline several attacks on a basic scheme based on HFE and describe a new attack on HFEz, a cryptosystem based on special polynomials over finite fields with a modification, which discards a portion of the output from the initial transformation. This ensures a dependency on more variables while keeping the same size of the field. The attack starts with a translation of HFE into HFE with branches, followed by a branch separating algorithm described in [Fel06]. The separation algorithm uses the public key to derive an operation, which induces (with addition) a non-associative algebra. Utilising some properties of non-associative algebras, a matrix, which can separate variables into distinct sets according to branches, is calculated. This leads to stripping off the HFEz modification and thus allowing us to attack directly the HFE polynomial. Powered by TCPDF (www.tcpdf.org)
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