Research & Implementation Of Identity Authentication Mechanisms In BWMAN Based On 802.16

With the rapid development of computer technology, people are being connected by all kinds of wire or wireless networks. WiMAX (Worldwide Interoperability for Microwave Access) is a rising Wireless Metropolitan Area Network (WMAN) technology. The compatibility and inter-operability of WiMAX is ensured by IEEE 802.16 standard. WiMAX will connect IEEE 802.11(Wi-Fi) hotspots to the Internet and provide a wireless extension to cable and DSL for last mile broadband access.Because of its wireless characteristic, the security of the network is very important. It is necessary for WiMAX to adopt a strong authentication mechanism. IEEE 802.16 supports two kinds of communication modes: PMP and Mesh. Several authentication methods are supported depending on the type of different network architectures. Regarding the security defect of one-way authentication in PMP mode, this paper focuses on the EAP-TTLS access authentication mechanism of WiMAX. EAP-TTLS is mostly used for mutual authentication. It is an extention of EAP-TLS, and can provide mutual authentication and dynamic key distribution between client and server. Moreover, EAP-TTLS is seamless compatible with the current system architecture of RADIUS.Depending on the WiMAX network structure, we design the EAP-TTLS authentication mechanism in WiMAX and implemented the client solution of RADIUS protocol to support EAP-TTLS authentication mechanism. The solution has been simulated by tests and the result indicated that this solution can effectively function as an authentication module.Being different from PMP mode in which all subscriber nodes must directly communicate with base station, Mesh network is a newly emerging network structure based on multi-hop routing; it has both cascaded and peer to peer network structure. As the topological structure change constantly with the node's movements, and there is no fixed centre node, Ad hoc is more apt to receive attacks. The security problem is more outstanding.It's an effective method to realize security goal that introducing trust management. We studied the free software PGP (Pretty Good Privacy) which uses asymmetry encryption algorithm to protect electronic mails and data files from being tampered or decrypted, then put forward an improved trust model. This trust model offers reliable security performance for the communication establishment process of the nodes in Mesh network. Meanwhile, for the secure routing problem which exists after the nodes have successfully established connections, we used Marsh's situational trust model for reference, simplified it, improved it and then applied it to the route selecting in Mesh network; this method can increased the reliability of data transmission.At last, it points out future research topics of this idea.