Cyber-physical System Attack Detection And Security Control

In recent years,with the continuous improvement of computer technology,information processing technology and control technology,human society is increasingly developing in the fields of network,information and intelligence.Smart grid,smart transportation,smart medical and other information systems have greatly facilitated the way of life.These systems integrate embedded system,computer network,control theory,wireless sensor network and other facilities,and realize the efficient cooperation and interconnection of physical space and information space,and deep integration.In this context,the concept of cyber physical system(CPS)came into being.In essence,information physical system can be regarded as a control system that information space and physical space connect and communicate through network structure.In the future,the interconnection of everything in the world requires higher the openness of CPS,which would in turn suffer frommore and more serious security threats.Therefore,the safety of CPS attracts the attention of many scholars,and various safety issues of CPS are discussed.From the perspective of control theory,it is of great theoretical and practical significance to study the safety of CPS.At present,the CPS problems studied from the control theory mainly include: the design of CPS model,the analysis of CPS performance,the behavior modeling of attackers,the protection of privacy and so on.Although these researches have made great progress and can be implemented in practical applications,there are still many deficiencies.For example,most of the current attack detection is designed for a specific attack,which can not be directly applied to other attacks,and many of the current researches focus on attack strategy from the perspective of the attackers,while few of the relevant researches focus on the effect of the attack from the perspective of the system;most of the current relevant privacy protection algorithms use traditional information security algorithm,lack of privacy protection algorithm design for specific application scenarios.Motivated by the discussions above,this paper focuses on the attack detection and privacy protection of discrete-time linear time-invariant system.The main work is as follows:1)This paper summarizes the domestic and abroad research progress of CPS,and analyzes the existing shortcomings.2)From the perspective of system,the unified model of CPS under attack is established.Based on the attackers' ability,the attack behavior of the attackers is described.3)For the CPS model with only sensors attacks,the necessary and sufficient conditions for the detection of attacks are given based on the definition of sparse observability.By assuming that some sensors are under protection,the corresponding attack detector and state estimator are designed.It is expounded that the sensors under protection play an important role in improving the efficiency of attack detection and state estimation.4)For the application of average consensus of CPSs,this paper analyzes the common prob-lem of privacy leakage in consensus algorithms.Based on the traditional information security algorithm and the mechanism of random number confusion in Statistics,an aver-age consensus algorithm is designed to protect the initial state,while realizing the average consensus.