Analytical Study of IEEE 802.11i and its Improvement

Abstract

IEEE 802.11i is the standard designed by IEEE to provide the enhanced MAC security in the wireless network. The authentication process consists of three entities; the supplicant (wireless device), the authenticator (access point) and the authentication server (de facto RADIUS server). IEEE 802.11i provides mutual authentication between the network access point and user devices prior to user connectivity. The protocol consists of several parts, including an IEEE 802.1X authentication phase which uses TLS over EAP, the 4Way Handshake to establish

a fresh session key, and an optional Group Key Handshake for group communication. This study analyzes the IEEE 802.11i with respective to data confidentiality, integrity, mutual authentication and availability. Theoretically the analysis of the protocol was done by using Protocol Composition Logic (PCL) and practically it was done by using standard network simulator namely ns2 (Network Simulator 2) and also proposed the improvement to the protocol which was also verified by using PCL theoretically and ns2 practically. IEEE 802.11i appears to provide effective data confidentiality and integrity when CCMP is used. But since 802.11i design does not emphasize availability, several DoS attacks are possible. This study reviews the known DoS attacks on unprotected management frames and EAP frames, and discusses the way to minimize them in 802.11i. Keywords: IEEE 802.11i, IEEE 802.1X, RADIUS, 4-Way Handshake, Group Key Handshake, Denial of Service, Authentication, Key Management, Protocol Composition Logics.