The Research Of Communication Security Problem In Wireless Personal Area Networks

Wireless personal area networks(WPANs) based on Bluetooth technology are low-cost, low-power, and ad-hoc connectivity wireless personal environment. While the fast-developing wireless technology is becoming more and more popular for use in our life, it is of great interests to invesigate the security of WPANs. The objective of this dissertation is to evaluate the security performance of Bluetooth WPANs, and to point out possible security flaws in the Bluetooth WPANs system. In the mean time, the basic theory and technology are provided for future design of self-owned security communication system.Background information is presented in the dissertation about Bluetooth system and security policy in WPANs, and five criterias are proposed for designing secure WPANs. The noise-immunity and anti-interference performance of Bluetooth WPANs is evaluated in adverse environment including adjacent-channel and co-channel interference. In addition, five types of hopping sequences for the Bluetooth WPANs are implemented in FPGA in the research works. On the other hand, simulated attacks are designed to verify the security performance of Physical Layer and the potential defects in security are mended. In the Link Layer, after simulation of almost all security algorithms, the method of attack detection and the analytical method, based on BAN formal language logic, are introduced to fully evaluate the security protocol in the Link Layer. Several security faults are found out and the corresponding improvements are proposed.An advanced general exponentiation algorithm based on the Yacobi method is proposed for evaluating the exponentiation algorithm. Simulations have been carried out to compare the proposed method with those of previous methods on performance, we find from the simulation results that our method is characterized as faster calculation speed and convenience in seeking a reasonable trade-off between calculation speed and memory size. This method is especially suitable for embedded encryption system.Based on the above research works, an integrated security protocol stacks is built for Bluetooth WPANs. The analysis for key algorithms is given in this paper. The software simulation for all these algorithms has been completed. They are validated by comparing with the Bluetooth Specification and testing for numerous times. Based on lots of simulations and experiments, we conclude that although the security of Bluetooth is inadequate for many serious security-sensitive areas, its security performance for its general application is still acceptalbel except relatively weak PINdesign. Our improved measures will help to enhance the security performance of WPANs.