Research on OPC UA security

OPC Unified architectures (OPC UA) is a new software interface specification and application framework based on web service for plant automation systems which communicate with each other over the internet. The security issue holds the key to its development for technology feature based on web service. In this paper, the OPC UA security issues are discussed from the two views of network environment security and communication security in OPC UA applications. The network security deployment solution based on distributed firewall was proposed to ensure the host of OPC UA server and client against the different attacks. Sequentially the improved OPC UA security model based on the existing model was presented. A security strategy management module was added into the model, by configuring the module, the security characteristic of OPC UA applications system can adapt to the different security level. At last the information model of the security model is designed. By the above means, the OPC UA communication security and communication efficiency can be balanced better, and it provides the guideline for the development of OPC UA server and the OPC UA applications.