| Wireless Networks have become dramatically widespread in the last twenty years. Telecommunication networks, as the first wireless networks available for civilian use, have significantly influenced the world, with voice being the primary application at that time. The popularity of Wireless LANs (WLAN) began at the end of 1990s and WLANs have grown rapidly because of their convenience, cost efficiency, and ease of integration with other networks and network components. Data, exceeding voice, has quickly become the dominant traffic in networks [21]. Almost at the same time, Bluetooth, the wireless technique used to remove remaining wired connections, has become standard equipment embedded in wireless devices. However, wireless networks also have many security issues. Passive/active eavesdropping, man-in-the-middle attacks and Denial-of-Services (DoS) attacks are easier to launch in wireless networks compared with wired networks. Therefore, security needs to be extended to low layers. As a result, IEEE 802.11 networks and Bluetooth have defined their own link layer security protocols for data confidentiality, integrity, and device authentication.;This thesis investigates the link layer security protocols of IEEE 802.11 networks and Bluetooth networks. We focus on how the link layer security protocols protect data traffic over wireless networks to determine if they supply confidentiality, integrity, and device authentication. Protocol weaknesses and attacking methods are investigated. In Chapter 2, we introduce security protocols - WEP, WPA, and IEEE 802.11i - for IEEE 802.11 networks. We analyze the security features of RC4, Temporal Key Integrity Protocol (TKIP), Michael, Counter with CBC-MAC Protocol (CCMP), and the authentication procedures. Bluetooth is investigated in Chapter 3. We introduce Bluetooth networks to provide an overview of the architecture. Then we analyze Bluetooth pairing strategies and some attack methods. Because the protocols discussed are de facto industry standards, we only evaluate the security strength of the protocols and, if possible, give practical suggestions to address potential threats. |
