Security issues in privacy and key management protocols of IEEE 802.16

Without physical boundaries, a wireless network faces many more security threats than a wired network does. Therefore, in the IEEE 802.16 standard a security sublayer is specified in the MAC layer to address the privacy issues across the fixed Broadband Wireless Access (BWA). Several articles have been published to address the flaws in IEEE 802.16 security after the IEEE standard 802.16-2001 was released. However, the IEEE standard 802.16-2004 revision does not settle all the discovered problems and additional flaws remain. This paper gives an overview of the IEEE 802.16 standard, focusing on the MAC layer and especially the security sublayer. We analyze the security flaws in the standard as well as in related works, and illustrate possible attacks to the authentication and key management protocols. Possible solutions are also proposed to prevent these attacks. Finally, we propose a security handover protocol that should be supported in the future 802.16e for mobility.