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Wireless networks security analysis
Szőcs, Juraj ; Vychodil, Petr (referee) ; Vymazal, Michal (advisor)
This master’s thesis deals with analysis of security in wireless networks. There are desc- ribed various methods of security systems, such as WEP, TKIP and CCMP. There is also realization of attacks against the wireless network and there is analysis of security weaknesses. Then there are discussed possible defense mechanisms. Part of this work was also analysis of local security in certain areas and evaluation of their security.
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Security of wireless computer networks
Jelínek, Martin ; Pelka, Tomáš (referee) ; Doležel, Radek (advisor)
The master's thesis deals with the issue of Wireless Local Area Network (WLAN) from the viewpoint of the security and functional principle of security mechanisms. The transition to the issue concerning the security is accompanied by the methods of wireless data transmission operating on the level of physical layer (FHSS, DSSS, OFDM, MIMO), which is followed by the summary of individual 802.11 standards. The next part deals with the issue of shared transmission medium (CSMA/CA), influence of interference and correcting mechanisms (RTS/CTS). Within the security, the principles of the authentication along with the commonly used methods of security (WEP, WPA, WPA2) are described in detail. The first part concerning security deals with the security in the form of the WEP protocol, which is considered insufficient nowadays and points out the imperfect implementation and the consequent risks. The following part describes the security in the form of WPA which eliminates the implementation weaknesses of the previous WEP security protocol. The description of commonly used mechanisms of authentication (PSK, 802.1x), required temporary key management (PTK, GTK), data integrity (MIC) and encryption which uses TKIP protocol are also included. The last part, possible WLAN security, is aimed at the full support of 802.11i standard, which is called WPA2 (sometimes RSN). That part describes the basic encryption security element CCMP, which is based on the AES block cipher modes. The practical part of the thesis deals with the security verification of current wireless networks. In the process of verification the accessible HW means and programming tools of Open Source Software (OSS) are used. By means of verification it has been pointed out that there are possible security risks resulting from the security method which has been used. Also several recommendations how to reduce the security risks of the used method to minimum are mentioned.
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Modern trends in Wi-Fi IEEE 802.11 networks security
Lieskovan, Tomáš ; Škorpil, Vladislav (referee) ; Endrle, Pavel (advisor)
This work treats the matters of wireless networks, Wi-Fi. The paper describes the various principles of coding, such as WEP, WPA and WPA2. At first the WEP security method is analyzed with the view of the fact that it doesn´t meet contemporary safety requirements, further its successor WPA, namely TKIP and AES authentication methods, and last but not least WPA2 which nowadays serve as a safety standard. The work assesses the safety risks of individual security methods and makes several recommendations to achieve maximum security for wireless networks. In the work a commercially available hardware and for free dissemination available software (Open Source) are used.
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Wireless Network Security
Sedlák, Břetislav ; Krajsa, Ondřej (referee) ; Lambertová, Petra (advisor)
Master thesis focuses on wireless network security. The thesis is divided in two parts. First part describes today’s used standards and their components, topology and security methods as stealth SSID, MAC addresses filtration, WEP, WPA and WPA2. The last three methods are described in detail. In second part there are realized attacks on above described methods of security. There are described attacks on WEP as KoreK chopchop attack, fragment attack, attack FMS, KoreK and attack PTW. Then is described the dictionary attack on passphrase by WPA/WPA2 with PreShared Key authentication obtaining, precomputed hash tables for faster passphrase finding and for using more core procesors during dictionary browsing. The last attack describes obtaining of keystream used for encrypting of frames by WPATKIP and then sending custom data to client. It is described how to carry out each attack and how to protect against them.
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Analysis of Cryptographic Algorithms 802.11
Vojtíšek, Jindřich ; Sobek, Jiří (referee) ; Novotný, Bohumil (advisor)
This work deals with wireless standard 802.11, primaly about security algorithms used in them. Further there is made analysis of algorithms WEP, WPA and WPA2. This algorithms are described how coding by them works and for easier understandig are added block schemes of their principles. In practical part is realized algorithms WEP, WPA and WPA2 in program Matlab simulink. Model is complemented by graphs which shows how data changes when comming throught this systems.
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Current trends in the security of Wi-Fi IEEE 802.11 networks
Blažek, Ondřej ; Škorpil, Vladislav (referee) ; Endrle, Pavel (advisor)
This work describes security options of 802.11 standard. Principle of WEP algorithm is described here, problem with his inicialization vector which leads to a statistical attack and revelation of his secret key. Moreover other principles of algorithms such as WPA, WPA2 are explained here along with a practical demonstration of bruteforce attack in a practical part of the thesis. Also the influence of encryption on network throughput is tested here using tool Iperf.
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Attacks on Standard 802.11
Burian, Vojtěch ; Horváth, Tomáš (referee) ; Novotný, Bohumil (advisor)
Thesis is concerned about standard 802.11 especially wireless network security in historical and in current way. First part is focused on WEP secured wireless network problematics. Consequently, in different point of view we are focused on network security which was developed recently, for example WPA and WPA2 security. It will be marked the basic functioning and brief overview of standard 802.11, introduction to the known attacks on wireless network security and also indicate the main mistakes. Many older devices have only WEP security. Therefore, in this thesis is designed better and more coherent system of security of the WEP protocol. As well modern methods of security WPA and WPA2 are included. Second part is focused on the simulation of attack on security networks. In this part the problematic with beaking security WEP, WPA and WPA2 is discussed.
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Security of wireless computer networks IEEE 802.11
Škodák, Jaroslav ; Jeřábek, Jan (referee) ; Koutný, Martin (advisor)
This work describes available and used standards, protocols and mechanisms used to secure IEEE 802.11 wireless networks. In the next section are listed vulnerabilities and possible attacks against different types of security. The principles of individual attacks on authentication, WEP security and WPA/WPA2 personal mode are described and realized using various software especially linux program aircrack-ng. Password for WEP security is obtained by passive eavesdropping data, using ARP replay injection and by creating own frames. The last two methods are used to generate traffic on the network, which is captured and then used to derive the WEP password. By injecting ARP frames, password was found in the number 60 000 captured frames and about 180 000 frames of data was needed for passive method. Decryption of WEP frame was done by fragment and KoreK chopchop attacks. This decrypted frame could be used to create fake frames and obtain WEP password. Brute force attack is realized for security WPA (WPA2) personal mode (often due to lack of strong password) by comparing password (passphrase) from password list. Speed of comparing is about 200 passwords/s.
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Preventing attacks 802.11
Štefanec, Filip ; Kenyeres, Martin (referee) ; Novotný, Bohumil (advisor)
The main focus of this bachelor's thesis is on issues with security in wireless networks, based on standard 802.11. It includes description of most used encryption process and authentication methods in 802.11 networks. Also it explains functionality of EAP and RADIUS protocols, which are the main part of WPA/WPA2-Enterprise security mode. At the end of the thesis there is simulation of basic attacks on standard 802.11 and consequently desing and implementation of security, which prevents similar attacks. Implementation of security is based on authentication of clients through RADIUS server.
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Attacks on Standard 802.11
Burian, Vojtěch ; Horváth, Tomáš (referee) ; Novotný, Bohumil (advisor)
Thesis is concerned about standard 802.11 especially wireless network security in historical and in current way. First part is focused on WEP secured wireless network problematics. Consequently, in different point of view we are focused on network security which was developed recently, for example WPA and WPA2 security. It will be marked the basic functioning and brief overview of standard 802.11, introduction to the known attacks on wireless network security and also indicate the main mistakes. Many older devices have only WEP security. Therefore, in this thesis is designed better and more coherent system of security of the WEP protocol. As well modern methods of security WPA and WPA2 are included. Second part is focused on the simulation of attack on security networks. In this part the problematic with beaking security WEP, WPA and WPA2 is discussed.
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