基于伪周期控制信号编码的重放攻击检测

Replay attack detection method based on pseudo periodic control signal coding

现有基于控制信号编码的信息物理系统重放攻击检测方法主要是通过判断检测函数值的大小是否超出给定阈值来实现检测,这类方法普遍存在检测率与系统控制性能损失之间的矛盾.鉴于此,提出一种基于伪周期控制信号编码的检测方法.首先,在控制信号中加入预先设计的伪周期随机编码信号,并构造与之对应的伪周期测量值补偿信号,验证当系统矩阵稳定时,补偿信号的周期性;然后,对接收到的测量值信号,利用不同补偿信号进行补偿,获得检测函数最小时对应的补偿信号在周期中的位置;最后,通过比较该补偿信号与实际控制量水印信号在周期中的位置实现对重放攻击的检测.仿真实验结果表明,采用所提出方法,只需比较采用不同补偿信号下检测函数值的相对大小,便能够在有效地检测重放攻击的同时,降低控制编码信号的方差并减小系统控制性能损失.

The existing replay attack detection methods of cyber-physical system based on control signal coding mainly realize the detection by judging whether the value of the detection function exceeds a predetermined threshold,which results in a conflict between the detection rate and the loss of system control performance.Therefore,this paper proposes a detection method based on pseudo periodic control signal coding.Firstly,the pre-designed pseudo periodic random coding signal is added to the control signal,and the corresponding pseudo periodic measurement compensation signal is constructed.The periodicity of the compensation signal is proved when the system matrix is stable.Then,the received measurement is compensated by different compensation signals to obtain the position of the compensation signal corresponding to the minimum value of the detection function in the period.By comparing the position of the compensation signal and the actual watermark signal in the time,the replay attack is detected.The simulation results show that the proposed method only needs to compare the relative values of the detection function under different compensation signals,so as to effectively detect the replay attack,decrease the variance of the control coding signal and reduce the performance loss of the system control.