Reasearch On Theory And Application Of Key Generation Scheme Based On ZigBee System

In order to ensure the security of wireless communication,transceivers are required to encrypt the transmitting data by sharing key.Since wireless physical layer channel is time-varying and space-varying,generating keys by using these characteristics has become a hot research topic in recent years.However,there are some obstacles in related application of physical layer channel characteristics.For example,the key generation rate is not fast and the bit error rate is high.Usually,secret key generation schemes that based on physical layer channel characteristics ordinarily include following aspects:channel measurement,channel quantization,information negotiation and security enhancement.Based on the comprehensive consideration of previous studies,the filtering channel compensation is proposed after channel estimation.In this thesis,the Wiener filter is used to suppress the impact of external factors,such as noise.Whether the channel compensation is conducted is analyzed in simulation.The numerical results demonstrated that the consistency for the secret key generation is improved after channel compensation.Moreover,as the order of filter increased,the performance improvement is more significant under low signal-to-noise ratio(SNR).In order to verify the effectiveness of channel compensation in practical environment and study the impact of different environments on the performance of key generation,this thesis mainly focuses on the channel measurement in the ZigBee wireless communication systems and the corresponding analysis on the measurement data.By comparing the different secret key generation schemes with and without channel compensation,we found out that the consistency and rate of key generation schemes with channel compensation is better than the one without filtering processing.In addition,by measuring and analyzing the effect of different scenes such as indoor,outdoor,stationary,moving state and communication distance,it is found that in a certain range of communication,a fast moving state is able to facilitate the generation of the security keys.