Abstract. Wireless LAN (WLAN) refers to the wireless network environment constructed indoors or outdoors, by using either the radio or light wave technology instead of wire signals from the hub to such clients as PCs (Personal Computer), notebook PCs and PDAs. TGf (Task Group F), among IEEE 802.11 WGs (Working Groups), is currently under formulation of the standard protocols for communication between WLAN Access Points (APs). This Group has proposed IAPP (Inter Access Point Protocol) designed to secure the interoperability between AP sets produced by different vendors. This is a protocol for securing mobility among APs within sub-networks. It offers seamless connectivity between stations (STAs) by sharing security context or Layer 2 forwarding data between APs without re-authentication when STAs move around among them. In this paper, we propose a mechanism to enhance the wireless LAN security protection related information as WEP key that can occur during message transmissions betwee...