Abstract

Internet based supervisory control and data acquisition (SCADA) systems are real time systems, which is deployed to control processes. The open nature of internet requires careful consideration of data security measures. To ensure data security, the system should consider integrity, confidentiality and protection against unauthorized users. This paper presents a scheme for authorized SCADA commands in real time process control. The commands can be bound with the issuer of the command. In case of any dispute that who has issued the command it can be proved, who has issued the command and further the command is validated at receiver end that it has not been modified in its way on network. The scheme has been implemented with XML policy authorization with XMLSec Library and Vijeo Citect 6.0.