Encrypted Control System with Quantizer

TL;DR

This paper introduces an encrypted control system that combines Paillier cryptography with a dynamic quantizer, enabling real-time operation and stability in networked control systems while balancing security and processing efficiency.

Contribution

It proposes a novel encrypted control framework integrating a sensitivity-adaptive quantizer with Paillier encryption, ensuring stability and real-time performance.

Findings

Achieves asymptotic stability for linear systems

Balances cipher strength and processing time effectively

Extends to event-triggered and nonlinear control systems

Abstract

This paper considers the design of encrypted control systems to secure data privacy when the control systems operate over a network. In particular, we propose to combine Paillier cryptosystem with a quantizer whose sensitivity changes with the evolution of the system. This allows the encrypted control system to balance between the cipher strength and processing time. Such an ability is essential for control systems that are expected to run real-time. It also allows the closed-loop system to achieve the asymptotic stability for linear systems. Extensions to event-triggered control and nonlinear control systems are also discussed.