This paper presents a secure and private implementation of linear time-invariant dynamic controllers using Paillier's encryption, a semi-homomorphic encryption method. To avoid overflow or underflow within the encryption domain, the state of the controller is reset periodically. A control design approach is presented to ensure stability and optimize performance of the closed-loop system with encrypted controller.
Murguia Rendon, C. G., Farhad, F., & Shames, I. (2020). Secure and Private Implementation of Dynamic Controllers Using Semi-Homomorphic Encryption. IEEE Transactions on Automatic Control, 65(9), 3950-3957. https://doi.org/10.1109/TAC.2020.2992445