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Network-Based Application Recognition
Štourač, Jan ; Barabas, Maroš (referee) ; Malinka, Kamil (advisor)
This thesis introduces readers various methods that are currently used for detection of network-based applications. Further part deals with selection of appropriate detection method and implementation of proof-of-concept script, including testing its reliability and accuracy. Chosen detection algorithm is based on statistics data from network flows of tested network communication. Due to its final solution does not depend on whether communication is encrypted or not. Next part contains several possible variants of how to integrate proposed solution in the current architecture of the existing product Kernun UTM --- which is firewall produced by Trusted Network Solutions a.s. company. Most suitable variant is chosen and described furthermore in more details. Finally there is also mentioned plan for further developement and possible ways how to improve final solution.
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Audio steganography and IP telephony
Hrinčárová, Monika ; Drápal, Aleš (advisor) ; Kozlík, Andrew (referee)
Steganography is a technique which hides secret information. In this work, we will hide a secret information in the packets which are produced during a Skype call. Skype is one of the best known and the most widely used VoIP applications. We will propose, describe and implement a steganography method by which we will send the secret message during the Skype call. For embedding the message into packets and extracting them, we will use steganographic method called matrix encoding. To avoid packet loss, we will increase the robustness of this method by error-correcting and self-synchronising codes. As error-correcting codes, we will use the binary Hamming (7, 4) -codes and for the self-synchronising, we will use T-codes. 1
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Audio steganography and IP telephony
Hrinčárová, Monika ; Drápal, Aleš (advisor) ; Kozlík, Andrew (referee)
Steganography is a technique which hides secret information. In this work, we will hide a secret information in the packets which are produced during a Skype call. Skype is one of the best known and the most widely used VoIP applications. We will propose, describe and implement a steganography method by which we will send the secret message during the Skype call. For embedding the message into packets and extracting them, we will use steganographic method called matrix encoding. To avoid packet loss, we will increase the robustness of this method by error-correcting and self-synchronising codes. As error-correcting codes, we will use the binary Hamming (7, 4) -codes and for the self-synchronising, we will use T-codes. 1
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The transfer and protection of information in mobile telecommunications
Pacák, Pavel ; Ivánek, Jiří (advisor) ; Pavlásková, Eliška (referee)
Charles University in Prague Faculty of Arts Institute of Information Studies and Librarianship Study program: Information Studies and Librarianship Field of study: Information Studies and Librarianship Pavel Pacák The transfer and protection of information in mobile telecommunications Bachelor thesis abstract The work focuses on the transfer and protection of information in mobile telecommunications. First, historical development of each technology used is introduced. Also different forms of thread which user can face in every day use of his cell phone are listed. In the end few possible solutions of security policy are presented. Possible ways of communication with higher level of security which can be used with your cell phone are the conclussion.
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Analysis of voice over IP protocols
Boháček, Milan ; El Bashir, Robert (advisor) ; Hojsík, Michal (referee)
In the presented work we focus on both implementation and protocol of the voice over IP application Skype. We analyse several versions of Skype clients and deduce inner workings of the Skype protocol. We present details about the cryptographic primitives used by the Skype clients and their impact on the security of the communication. We emphasize several places of suspicious leaks of the internal states of random generators and deduce rules for the detection of the Skype traffic on the firewall. In the end, we mention a simple enhancement of the current Skype clients that, in practice, can detect an ongoing eavesdropping.
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Evaluation of E-learning Tools
Šnajdr, Pavel ; Smutný, Milan (referee) ; Kopecká, Jana (advisor)
Náplní semestrální práce "Evaluation of E-learning Tools" je přiblížení e-learningových nástrojů čtenáři a zhodnocení možností využití e-learningu jako samostatné složky výuky. První část práce se zabývá definováním termínu e-learning a poskytuje zasazení do historického pozadí. V dalších částech se blíže zabývá jednotlivými hardware a software nástroji. E-learningové nástroje, kterými se práce zabývá, jsou základní kancelářské nástroje, stránky pro sdílení videí s výukovým obsahem a v poslední části sociální sítě a jazykové programy a zhodnocení výhod, nevýhod a vlivu na studenta.
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Detection of Peer-to-Peer Communication
Letý, Pavel ; Kováčik, Michal (referee) ; Bartoš, Václav (advisor)
This thesis is focused on issues in detection of P2P network from NetFlow. In the theoretical part of this work are introduced actual techniques in detection of this communication in network. There are presented their advantages and disadvantages too. The biggest attention is focused on the classification scheme of Mr. Bashir which deals with a detection of a protocol BitTorrent and a Skype application from Netflow. Following this scheme is designed a detection module for a modular system of a traffic analysis Nemea, developed by Cesnet organization. In the practical part of this work is introduced the implementation of this module. There are also presented results of experiments with real data.
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Detection of Dynamic Network Applications
Juránek, Michal ; Kaštil, Jan (referee) ; Tobola, Jiří (advisor)
This thesis describes methods of detection of simple voice communications of encrypted VoIP calls between two Skype clients. The elements of network and its communication principles are described. Three approaches to classification are analyzed. The first approach performs the classification by content of network packets using Pearson's chi2 test of goodness of fit, the second approach by characteristics of network flows by means of naive Bayesian classification. The third approach describes ways of detecting signaling messages. The detector application is implemented on the basis of chosen methods.
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Identifying Skype Traffic Using NetFlow Data
Šebeň, Patrik ; Veselý, Vladimír (referee) ; Grégr, Matěj (advisor)
NetFlow is a network protocol commonly used for collectiong IP traffic information. But there is a way to use this collected data for indentifying clients in Skype communication. This paper describes identifiable patterns in Skype protocol and how to find them in NetFlow data. This way we can identify nodes and supernodes in Skype network.
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