This paper investigates the security issue of the data replay attacks on the control systems. The attacker is assumed to interfere with the control systems process in a steady-state case. The problem is presented as the standard way to attack, which is storing measurements and replaying them in further times to the system. The controller is assumed to be the LQG controller. The main novelty in this paper can be stated as proposing a different attack detection criterion by using the Kullback-Leibler (K-L)divergence method to cover more general control system problems with these attacks and with higher-order dynamics. Also, there exists a packet-dropout feature in transmitting the data as another contribution of the paper. Formulations and numerical simulations prove the effectiveness of the newly proposed attack detection procedure by having a quick response to occurred attacks with various values of the considered packet-dropout coefficient. Although, in previous approaches, the trade-off between attack detection delay or LQG the performance was significant, in this approach it is proved that the difference in this trade-off is not considered in early moments when the attack happens since the attack detection rate is rapid and thus, these attacks can be stopped with defense strategies in the first moments with the proposed attack detection criterion.

本文研究了控制系统上的数据重放攻击的安全性问题。假定攻击者在稳态情况下会干扰控制系统的过程。问题是作为攻击的标准方法而提出的，该方法是存储测量值，并在以后将其重放给系统。假定该控制器为LQG控制器。本文的主要新颖之处可以说是通过使用Kullback-Leibler（KL）发散方法来提出不同的攻击检测标准，以涵盖这些攻击和更高阶动力学的更一般的控制系统问题。另外，在传输数据方面存在丢包特征，这是论文的另一项贡献。公式和数值模拟通过以各种考虑的丢包系数值快速响应发生的攻击，证明了新提出的攻击检测程序的有效性。尽管在以前的方法中，攻击检测延迟或LQG在性能之间的折衷是显着的，但是在这种方法中，已经证明，由于攻击检测率高，因此在攻击发生的早期不会考虑这种折衷的差异。攻击速度很快，因此可以使用提议的攻击检测标准在第一刻使用防御策略停止这些攻击。