Security Model to Secure legacy OPC Server and Client Communication

Steel Authority Of India Limited (SAIL) is the leading steel making company in India. SAIL has its own private network connecting different production units located at Durgapur, Bokaro, Bhilai, Rourkela steel plants etc and corporate offices at Delhi, Kolkata etc. Some of the links in private network are also connected to open and larger network such as internet to communicate with suppliers and customers. Therefore the internal network of SAIL is private as well as public network. So security for this network is most important. Everyday a number of attacks are launched. Among them service attacks are growing exponentially. Since private network of SAIL is indirectly connected to public network through internet. Therefore OPC connected to PLC in steel plants are also indirectly connected to internet. Since it is not possible to route data from OPC through firewall and switching off the firewall makes the plant network insecure and prone to viruses like STUXNET. In this paper, I will propose a security model to secure OPC client and server communication

Keywords: OPC Service Provider, OPC Data Client, OPC Service Broker, Service Oriented Architecture