IEEE 802.16 Protocol Privacy Sublayer Implement And Security Analysis

Due to the opening of wireless medium, wireless systems are much more vulnerable than wireline system. Besides, the safety threantens from air make it more difficult to control.802.16, a new and competitive wireless access technology, has a great potential of commercialization. However, authentication, key management and dada protection are necessary to protect the technique from safety threats and make it survive in market.This thesis focuses on 802.16 privacy sublayer. To be specific, PKM(Privacy Key Management) is analyzed and the full process of authentication and key negotiation is explained in detail. Besides, we discuss the pros and cons of PKM and put forward some methods to enhance the safety of the protocol.According to the requirements for operating 802.16 WMAN, a new algorithm is proposed for RADIUS server which can achieve 802.16 privacy sublayer. In our proposed algorithm, a special RADIUS server is set up as authentication server. SS (applicant) sends identity authentication request to BS (authenticator), and then BS sends the requests to RADIUS server who is responsible for authentication.With the help of the special RADIUS server, our algorithm is advantageous at reducing the processing burden of BS, which will improve the stability and robustness of the system.Analysis on key issues, 802.16 privacy sublayer key transfer protocol, BS & SS key synchronization mechanism, AK&TEK state machine on SS side, is provided. Additionally, we pay particular attention to some important components such as communication protocol between BS and RADIUS server, detail implement of BS and detail implement of SS. Our algorithm is proved to be successful in Linux system.An improved algorithm based on EAP protocol for transmission between BS and RADIUS server is put forward to ensure the expansibility of privacy sublayer. Furthermore, the use of random numbers is incorporated to cope with the re-used attacks in privacy sublayer.Based on our knowledge and practical experience on design, implementation and test, we point out the advantages and disadvantages in 802.16 privacy sublayer, which will be beneficial for the improvement of this standard.In conclusion, the emphasis of this thesis is on the designing principles of (IEEE 802.16 protocol Privacy sublayer in MAC layer), which will be useful for clarifying and improving the overall function of privacy sublayer.