generates new encryption keys after various configurable intervals (a time period, a bit quantity, or even every frame), which makes it much more difficult to break. Message Integrity Code (MIC)-MIC introduces a kind of digital signature to each frame to ensure that messages are not tampered with or captured and replayed. It helps to thwart the introduction of unauthorized WAPs. 802.1 authentication framework-802.1X is a popular IEEE standard for port-based access control that is included in the latest wireless security specifications. This standard defines how to authenticate the identity of wireless (and wired) clients, such as via an external Remote Authentication Dial-in User Services (RADIUS) server or by using other authentication Chapter 15 WMANs, WLANs, and WPANs methods, such as Extensible Authentication Protocol (EAP). RADIUS is an authentication, authorization, and accounting (AAA) protocol for applica- tions such as IP mobility and network access. It works in both local and roaming environments. EAP, specified under IETF RFC 3748, is a protocol that allows incorporation of various external authentication methods- digital certificates, usernames and passwords, secure tokens, and so on- into wireless security environments. As used in 802.11 802. 1X provides a framework for robust user and device authentication, a feature that was missing from the original 802.11 standard. Like dynamic WEP, WPA generates unique keys for each associated client com- puter and takes care of distributing them securely. WPA2 is embodied in the IEEE 802. lli specification, and it is the most long-term solution of the current WLAN security standards. It is the latest-generation wire- less security environment, meant to enhance and supplant WPA. WPA2 differs from WPA in that it uses AES rather than RC4 and doesn't need a MIC because the same AES key is used for both encryption and integrity. WPA2 still relies on 802.1X for authentication. AES supports encryption keys of 128, 196, and 256 bits. All Wi-Fi hardware manufactured aft