An efficient encoding mechanism against eavesdropper with side channel information.

In this paper, we investigate the privacy-preserving problem in remote state estimation by extending the lightweight encoding mechanism (Yang et al., 2020) to a more competitive scenario, where the adversary can intercept the system data more effectively, i.e., it is considered to be able to gather data from both the channel and the side channel. A transferable framework based on side channel information is established for analyzing the validity of encoding mechanisms. By resorting to padding and random injecting, a lightweight encoding mechanism is proposed to resist eavesdropping attacks. Furthermore, a sufficient condition to ensure the privacy of information is derived by transforming the communication data. Finally, numerical examples are given to verify the results.