面向城轨云平台边界安全防护的动态信任管理方法

To address the problem of numerous borders and weak border protection in metro cloud platform，the collaborative interaction between the cloud and the industrial control network is analyzed， and a dynamic trust management method for border security protection of metro cloud platform is proposed. The method consists of abnormal behavior recognition，trust evaluation，trust updating，and trust-based dynamic access control. Based on the network topology of metro cloud-based integrated supervisory control system，three kinds of abnormal control commands are simulated，i. e.，unauthorized control commands，nonconforming control commands，and interference with normal control commands. The results show that the proposed method can effectively resist abnormal control commands initiated by malicious nodes. The changes in trust values vary for different nodes and different types of misbehaviors following the rule of“slow rise and fast fall”，thus ensuring fine-grained boundary protection for the metro cloud platform.