Control of a Chemical Reactor with High Precision Encryption Framework

The cryptographic security of the closed-loop systems is addressed in this work. This paper explores the possibility of applying homomorphic encryption within the closed-loop implementation of an LQ controller. This paper specifically discusses the integration of a fully homomorphic cryptographic algorithm to ensure the evaluation of LQ-based control law with encrypted state measurements. Such a closed-loop framework with encrypted process measurements allows the user to delegate the control law evaluation to cloud services without revealing the true values of state measurements. Specific results with the closedloop enabled with the homomorphic cryptographic algorithm are demonstrated in a disturbance rejection scenario involving a chemical reactor.