Research On Physical Layer Security Technology For Wireless Control System

With the rise of the fifth generation mobile networks(5G),wireless control system has been more and more widely used.Compared with wired cable connection,wireless network has the advantages of low cost,rapid deployment,and can improve the spatial freedom of the controller.However,the openness of mobile network brings more and more security challenges to wireless control system.From the perspective of physical layer security(PLS),this paper explores the wireless communication security characteristics under the joint design of control and communication in wireless control system,and focuses on the physical layer transmission security and access security technology in wireless control system.The specific work of this paper is as follows:1.Joint design of communication and control for physical layer security.In wireless control system,communication performance and control performance are influenced by each other.The smaller the convergence rate,the softer the device state changes,which represents better control performance,and also requires higher quality of service(Qo S)of wireless communication physical layer link.Based on the cooperative design of communication and control,the control subsystem model and communication subsystem model are established respectively,and the relationship between control constraints and communication constraints is discussed.Finally,the closed form expressions of control convergence rate and communication physical layer transmission reliability for physical layer security are derived.2.Research on transmission security technology for wireless control system.In the process of wireless transmission,eavesdropping attack has always been one of the biggest challenges of physical layer security.The security capacity represents the capacity difference between legal channel and illegal channel,which is an important index to measure the physical layer security.In the case of transmitting shared information and confidential information at the same time,how to maximize the shared capacity and security capacity of wireless control system is the main problem of this paper.To solve the above problems,this paper proposes an optimization algorithm based on exhaustion and a suboptimal algorithm based on power distribution factor to solve closed form solutions,and compares the effects of the two algorithms.At the same time,this paper focuses on the influence of control performance on the problem and solution process of maximizing the shared capacity and security capacity of the wireless control system,and obtains the real security capacity area of the wireless control system.3.Research on access security technology for wireless control system.Wireless control system contains a large number of sensors,controllers,actuators,controlled equipment and many other nodes.Because the controller node is the focus of access attack,this paper focuses on the access security technology from sensor to controller node.When the controller node is attacked maliciously or the identity is forged,the control security of the whole system will be seriously threatened,so that the production security can not be guaranteed,and eventually the factory will stop production.However,when the forgery data value reported by the attack node conforms to the specific statistical law,the existing strategies can not detect the attack in time.In this paper,a security detection scheme of "electronic watermark like" is proposed by camouflage sensor nodes and sending forged data to the controller.The controller can effectively detect the malicious activities of camouflaged sensor nodes by injecting private incentives only known by itself into the data and executing the specified test scheme during the operation of the system.Specifically,two test quantities are given in this paper,and the completeness and effectiveness of the test method are fully proved by simulation.