The Analysis And Research On IEEE802.16 Security Sublayer Of Wireless Metropolitan Area Networks

With the rapid development of computer technology, people are being connected by all kinds of wire or wireless networks. As a highly competitive wireless access technology, WiMAX and its marketing are concerned by many operators. However, due to the opening nature of WMAN's transmission medium, the security mechanism becomes a key problem in WiMAX network products'marketization. So the research on security mechanisms of WiMAX network is of great significance.Firstly, according to the security mechanisms of IEEE802.16d and IEEE802.16e, the processes of authentication mechanism, private key negotiation and data encryption between base station and mobile station, are established for the security sublayer in IEEE802.16 standard. The security of the processes is analyzed, and the messages between subscriber station and base station in IEEE802.16e are recomposed. Through adding random numbers and signature to the messages, man-in-the-middle attack, replay attack and DoS attack are defended.Secondly, a WPKI-based security mechanism for IEEE802.16e is proposed. By introducing the signText function of WPKI (Wireless Public Key Infrastructure), the improved mechanism fits the terminals with weak abilities and limited storage. In order to be compatible with PKI and raise resource utilization ratio, the mechanisim replaces the identifiers of the X.509 certificates used in the WiMAX with those of the WTLS certificates used in the WPKI. In view of the poor security of DES algorithm and 3DES algorithm, the proposed mechanism employs AES algorithm for private key transmission. The improved mechanism is described in details, and is theoretically analyzed. The code for MAC sublayer of WiMAX network is supplemented in NS2, and the improved mechanism is simulated. The analytical and experimental results show that the mechanism can defend the attacks in IEEE802.16e protocol, and satisfy the weak abilities of mobile terminals. The results demonstrate that the improved security scheme improves the performance, and fits the wireless networks.