Optimal Tradeoff Between Performance and Security in Networked Control Systems Based on Coevolutionary Algorithms

Networked control systems (NCS) have to be well protected with security mechanisms from malicious attackers on the network (e.g., Internet). However, the additional security mechanism might sacrifice the performance of the NCS due to limited system resources. This paper addresses the issue of the tradeoff between NCS security and the NCS real-time performance. Using a networked DC motor system as an example, a tradeoff model for performance and security on NCS is presented. This paper also presents a framework of performance-security tradeoff optimization based on coevolutionary genetic algorithm (CGA) for the networked DC motor system. Experiments show that CGA is highly efficient in finding the Nash equilibrium for the tradeoff model on NCS. The framework presented in this paper is also demonstrated to be an effective approach for performance-security tradeoff analysis and optimization on NCS.