National Repository of Grey Literature 152 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Module for Network Policy Monitoring in Flow Data
Piecek, Adam ; Kučera, Jan (referee) ; Wrona, Jan (advisor)
The aim of this master's thesis is to design a language through which it would be possible to monitor a stream of network flows in order to detect network policy violations in the local network. An analysis of the languages used in the data stream management systems and an analysis of tasks submitted by the potential administrator were both carried out. The analysis specified resulted in the language design which represents pipelining consisting of filtering and aggregation. These operations can be clearly defined and managed within security rules. The result of this thesis also results in the Policer modul being integrated in the NEMEA system, which is able to apply the main commands of the proposed language. Finally, the module meets the requirements of the specified tasks and may be used for further development in the area of monitoring network policies.
P4 Language-Based Description of Accelerated Device against DoS Attacks
Kuka, Mário ; Kekely, Lukáš (referee) ; Kučera, Jan (advisor)
This thesis describes the development of a networking device used to defend against (D)DoS attacks using P4 language. The main purpose was to design flexible device using P4 lan-guage based on already existing device, this would allow us to quickly react and respond to new more complex DDoS attacks. The design of the device dealt with the transfer of individual parts of the firmware into the P4 language. Subsequently, the entire device firmware was designed for hardware accelerators with FPGA technology. The firmware had been designed with respect to the limitations of current P4 language compilers. The device has been tested under laboratory conditions for functionality and performance. The device will be deployed in the network infrastructure of CESNET.
Heuristic Methods for the Mitigation of DDoS Attacks that Abuse TCP Protocol
Goldschmidt, Patrik ; Wrona, Jan (referee) ; Kučera, Jan (advisor)
TCP SYN Flood is one of the most wide-spread DoS attack types used on computer networks nowadays. As a possible countermeasure, this thesis proposes a network-based mitigation method TCP Reset Cookies. The method utilizes the TCP three-way-handshake mechanism to establish a security association with a client before forwarding its SYN data. The algorithm can effectively mitigate even more sophisticated SYN flood attacks at the cost of 1-second delay for the first established connection. However, the method may not be suitable for all the scenarios, so decision-making algorithm to switch between different SYN Flood mitigation methods according to discovered traffic patterns was also developed. The project was conducted as a part of security research by CESNET. The discussed implementation of TCP Reset Cookies is already integrated into a DDoS protection solution deployed in CESNET's backbone network and Czech Internet exchange point at NIX.CZ.
Mitigation of DoS Attacks Using Neural Networks
Odehnal, Tomáš ; Wrona, Jan (referee) ; Kučera, Jan (advisor)
This bachelor's thesis deals with design and implementation of two approaches as protection against SYN Flood attacks, which are part of DoS attacks. Nowadays Denial of Service attack are very widespread and their execution are quite simple. While they can cause big financial damage to internet or service providers. The purpose of this work is to determine that conventional algorithmic approach and heuristic approach using neural network are capable of SYN Flood attacks mitigation. Implementation of both approaches were done by their design. Then both implementations were tested.
Testing of Device for DoS Attack Protection
Burzala, Matúš ; Vrána, Roman (referee) ; Kučera, Jan (advisor)
This thesis deals with testing of a device for (D)DoS protection DCPRO, that is developed within the CESNET association. The aim of the thesis was to design and implement an extendable testing system, which would allow automated testing of DCPRO device. In addition to the testing system, there was created a collection of tests for verification of functional and performance parameters of the device within the thesis. Afterwards, the developed system was integrated into a continuous integration system Jenkins. Particularly within the thesis there were created 109 specific test scenarios to test device firmware modules, 7 throughput test scenarios, 10 test scenarios to verify proper functionality of software modules dedicated to SYN Flood and amplification attacks protection, and one test for verification of device network routing ability. The developed testing system is easily extensible. In order to simplify a future extension of the system, there is a created template encapsulated in source files for new test creation and text part of the thesis contains guide how to create new tests.
IPv6 Prefix Sets Generator
Utkin, Kirill ; Kučera, Jan (referee) ; Matoušek, Jiří (advisor)
Due to the fast adoption of IPv6 protocol, number of IPv6 prefixes in routing tables are incessantly increasing. Based on this fact, development of new lookup algorithms is required. However, testing of those algorithms is highly dependent on size of datasets, which are not large enough for this purpose at the moment. Design and implementation of generator of IPv6 prefix sets, which will be based on currently using address allocation policies, is the main goal of this bachelor's thesis. Implementation of generator was preceded by study and implementation of the generator V6Gene. Validation of generated datasets were performed by comparing length distribution and level distribution of prefixes with the real world datasets. Finally, speed of the generating process and memory usage were compared for implemented generators.
The DPDK DNS Probe Application Extension
Doležal, Pavel ; Kučera, Jan (referee) ; Vrána, Roman (advisor)
This master's thesis is focused on extension of the DPDK DNS Probe application that monitors DNS traffic in high speed networks. It presents framework DPDK, which can be used for fast packet processing. General architecture of the DNS system is described as well as details of its components. Basic principles of transport protocol TCP are described. It introduces an effective design and implementation of DNS packet parsing to optimize DPDK DNS Probe's performance. It also introduces a design and implementation of processing DNS messages sent over TCP for export of traffic statistics. The application's performance was tested using a high speed traffic generator Spirent.
Stability of the sodium content in selected botanical reference materials
Kameník, Jan ; Kučera, Jan ; Borovička, Jan ; Havránek, Vladimír
Sodium mass fractions in NIST standard reference materials (SRM) SRM 1547 Peach Leaves and SRM 1515 Apple leaves determined by INAA in our laboratory in recent years has been higher than the certified values. Similarly, increased values were published for SRM 1547 by several other laboratories. The increased Na mass fractions was found also for freshly opened SRM 1547 bottle and for material originating from a different lab. Increased Na mass fractions were confirmed by ICP-MS analysis of both materials. Analysis of archived samples revealed that sodium mass fraction in materials stored in polyethylene capsules is in agreement with the certified values. The sodium content in the glass of SRM 1547 bottle was roughly 10 %. Direct measurement of the Na depth profile by micro-PIXE was not indicative whether Na is released, i.g., by a glass corrosion due to residual humidity in the botanical material. However, a model experiment with freshly prepared and pulverized peach leaves demonstrated that such a scenario is possible for leaf-based materials. Although the study was focused on two NIST materials, the process is possible for any material with rather low Na content.
Role of activation analysis in the preparation of reference materials
Kučera, Jan
The fundamentals of neutron activation analysis (NAA) and prompt gamma activation analysis (PGAA) and practices of both methods are briefly review, together with enlightening their specific role in the preparation of reference materials. The importance of homogeneity testing for the certification and use of reference materials (RMs) using NAA is appraised. Examples of the use of NAA and PGAA for the certification of element contents in environmental, biological, and material science RMs produced by world-leading institutions, such as U.S. NIST, IRMM, IAEA and by national institutions, as well, at the Nuclear Physics Institute within last almost 30 years are presented.
Provenancing of drugs based on their elemental composition determined by Neutron Activation Analysis - Feasibility Study
Kučera, Jan ; Kameník, Jan ; Sabol, J. ; Šesták, B. ; Kolář, P. ; Roman, M.
We analyzed five samples of heroine and five samples of cocaine seized in the Czech Repulic using instrumental neutron activation analysis (INAA). In the heroine speciments, we determined 16 trace elements in at least one of the samples analyzed, in the cocaine speciment, 9 trace elements could be determined. We have found remarkable differences, up to several orders of magnitude, in contents of the elements Na, Cl, Zna and Br, especially in the heroine samples. The accuracy of INAA results was proved by simultaneous analysis of a certified reference material NIST SRM 1547 Peach Leaves. The results of trace element determination in heroine samples are compard with those published by autors from abroad. The results obtained show a high potential of INAA for the drug elemental characteriaztion aimed at determination of their provenance, procedures used for their manufacturing and purification and cutting for the end users. The results achieved also suggest that it is desirable to analyze more samples with the final aim of establishing a database of elemental composition of drugs seized in the Czech Republic, which could possibly be extended later, in cooperation with foreign drug abuse and police bodies, at the international level.

National Repository of Grey Literature : 152 records found   1 - 10nextend  jump to record:
See also: similar author names
48 KUČERA, Jan
19 KUČERA, Jaroslav
25 KUČERA, Jiří
11 KUČERA, Josef
1 Kučera, J.
9 Kučera, Jakub
1 Kučera, Jaromír
19 Kučera, Jaroslav
25 Kučera, Jiří
3 Kučera, Jonáš
11 Kučera, Josef
3 Kučera, Jáchym
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