摘要:AbstractOne of the most important challenges for the application of cyber-physical systems (CPS) in smart industries is ensuring its security against cyber attacks. In this paper, we consider that the CPS is abstracted as a Discrete-Event System (DES), and we consider cyber attacks where the intruder eavesdrops the sensor communication channel to detect the occurrence of a sequence in the secret behavior of the system. In order to prevent the attacker from getting information from the sensor channel, we introduce a new cryptographic scheme based on events called event-based cryptography. We also define the property of confidentiality of DES, present a necessary and sufficient condition for ensuring this property, and propose a verification test.