Security enhancements of networked control systems using RSA public-key cryptosystem

To enhance the security of networked control systems, we propose the concept of secured control rules that is defined as a method that achieves concealing both signals over communication channels and parameters within controllers. Our method proposed in this study uses the homomorphism of the RSA cryptosystem to determine control signals directly from encrypted feedback signals and control parameters without performing any decryption processes. A numerical simulation confirms that the proposed method contributes to the improvement of security.