ABSTRACT
CONTENTS 5.1 Introduction................................................................................................... 76
5.1.1 Tragic End of WEP .............................................................................. 76 5.1.2 Intermediate Solution: Wi-Fi Protected Access ........................................ 78
5.2 WLAN Has New Clothes: IEEE 802.11i........................................................... 78 5.2.1 Port-Based Network Access Control ....................................................... 78 5.2.2 Mutual Authentication ......................................................................... 80 5.2.3 Key Hierarchy...................................................................................... 81 5.2.4 Key Management ................................................................................. 82 5.2.5 Confidentiality and Integrity ................................................................. 83 5.2.6 Pre-Authentication and PMK Caching ................................................... 84 5.2.7 Summary of the RSN Connection Process .............................................. 84 5.2.8 Cost of IEEE 802.11i ........................................................................... 86
5.3 WLAN Security in the Real World ................................................................... 88 5.3.1 Attacks on IEEE 802.11 Availability....................................................... 88 5.3.2 Wireless ARP Spoofing Attack ............................................................... 90 5.3.3 Evil Twin Attack .................................................................................. 91 5.3.4 Attacks on IEEE 802.11i ...................................................................... 92 5.3.5 Conclusion and Open Issues ................................................................. 92
References .............................................................................................................. 93
Taking into consideration the tremendous deployment of wireless communications, one can easily see that IEEE 802.11 [1] networks have played a major role in supporting universal mobile access (UMA) during recent years. Contrary to the popularity of wireless LAN technology, the topic of its security gained a rather negative publicity. The tragic end of Wired Equivalent Privacy (WEP) and the simplicity of accomplishing various denial-of-service (DoS) attacks resulted in abandoning the security at the logical link layer. To regain trust in the IEEE 802.11 technology and to provide the major security goals such as authentication, integrity, and confidentiality of the user data, the solution was finally presented in 2004, when the IEEE successfully finished the 802.11i ratification process. A stronger user authentication, a new underlaying cipher, and a more reliable integrity verification are the significant changes provided by this standard. Nevertheless, it seems that the utilization of IEEE 802.11i security did not follow the same growth as the deployment of the IEEE 802.11 technology resulting in a number of proprietary security solutions. Such solutions can easily be applied within existing infrastructures and business models, but at the price of allowing various link-layer attacks and often misleading the user’s sense of security.
