Periodic Real-Time Message Scheduling for Confidentiality-Aware Cyber-Physical System in Wireless Networks

Security problem poses a great challenge for running mission-critical cyber-physical systems in wireless networks. With the disregard of security factors, existing message scheduling schemes expose critical messages to security threats, especially by confidentiality attacks. Incorporating confidentiality improvement into message scheduling, we investigate the problem of scheduling periodic messages with both time-critical and security-critical requirements. Risk-based security profit model is built to quantitatively measure the security quality of messages. For a set of periodic messages, a Security-Slack based Heuristic Algorithm (SSHA) is proposed to judiciously allocate a slack time to the most suitable confidentiality level for each security-critical message. Experimental results evaluate the efficiency of SSHA. Compared to other heuristic schemes, specifically, the average security improvement can achieve up to 57.8% for SSHA.