Privacy input design for concealing transient output of linear SISO systems

In order to conceal the output information of a given linear SISO system, this paper considers a design problem of an artificial noise called privacy input, which is added to the output. To measure the confidential level of the output, we use the mutual information between the output and the concealed output. We then formulate a problem of designing a privacy input and a feedback gain such that a given linear SISO system is mean square asymptotically stable and satisfies a desired confidential level of the output. The solution is a generalization of our previous study. Numerical experiments demonstrate that the result is useful for concealing the transient output information.