Research On Key Generation Technology In Wireless Physical Layer

More and more Internet of Things?IoT?technologies are applied to many fields such as intelligent transportation,environmental protection,public safety,safe home,intelligent fire protection,etc.,bringing efficiency and convenience to people's daily lives.However,the data security problem that needs to be solved is followed,and ensuring data security is an important way to protect users'privacy.Traditional mechanisms for securing data are not applicable to IoT environments where terminal nodes are resource constrained.In recent years,the physical layer security technology has been continuously developed,and the wireless physical layer key generation technology can effectively solve the problem of key distribution and management in the traditional security mechanism,and thus has received extensive attention.This thesis focuses on how to improve the performance of key generation and key distribution in static wireless channel environment,which is oriented to point-to-point communication channel and multipoint network environment.Finally,the simulation experiment and verification system development were carried out.The main research work and innovative research results of this thesis are as follows:1.A channel measurement scheme based on frequency hopping technology is designed to enhance key agreement rate.Considering that the channel characteristics under static conditions are less volatile,and the randomness and consistency of key generation are low,a channel measurement scheme based on frequency hopping technology is designed.The experimental results show that the proposed method can help to obtain better channel volatility,and the key inconsistency at both ends of the communication is significantly reduced.The generated key can pass the test of eight detection functions in national institute of standards and technology?NIST?randomness standard.2.A preprocessing scheme based on principal component analysis?PCA?is introduced to further improve the key agreement rate and randomness.Considering the correlation of channel characteristic sequences,this thesis introduces the PCA method to decorrelate them.The simulation results show that the key disagreement rate is lower after PCA processing.The key disagreement rate of PCA based level crossings algorithm?PLCA?is about10^-3,while that of level crossings algorithm?LCA?is about10^-2.The key generated by PLCA has a higher passing rate in the randomness test,the average passing rate of PLCA is 0.86,while that of LCA is only 0.46.3.A lightweight group key distribution scheme is proposed to reduce bit error rate ?BER?and algorithm complexity of the group key.Two typical network topologies are considered in this thesis,such as star network and chain network.Aiming at the shortcomings of existing group key distribution schemes,a lightweight group key distribution scheme is proposed.The simulation and experimental results show that the lightweight group key distribution?LGKD?method has lower BER when distributing the group key,and the BER of the group secret key generation via received signal strength?GKRS?method keeps 3¹0 times that of LGKD.In addition,LGKD has a higher key capacity according to the derivation.4.A verification system of wireless physical layer key generation technology based on channel characteristics is designed and implemented.This system is composed of two PCs and three RF modules.The functions of channel measurement,quantization and consistency verification are realized.The anti-eavesdropping ability is verified and the practicability of the technology is proved.