On the Output Redundancy of LTI Systems

A Geometric Approach With Application to Privacy

Journal Article (2025)
Author(s)

Guitao Yang (Loughborough University)

A.J. Gallo (Politecnico di Milano)

Angelo Barboni (Zurich Insurance Group)

Riccardo M.G. Ferrari (TU Delft - Team Riccardo Ferrari)

Andrea Serrani (University of Bologna)

Thomas Parisini (University of Trieste, Imperial College London, Aalborg University)

Research Group
Team Riccardo Ferrari
DOI related publication
https://doi.org/10.1109/TAC.2025.3579219
More Info
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Publication Year
2025
Language
English
Research Group
Team Riccardo Ferrari
Issue number
11
Volume number
70
Pages (from-to)
7509-7522
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Abstract

This paper examines the properties of output-redundant systems, that is, systems possessing a larger number of outputs than inputs, through the lense of the geometric approach of Wonham et al. We begin by formulating a simple output allocation synthesis problem, which involves “concealing” input information from a malicious eavesdropper having access to the system output, while still allowing for a legitimate user to reconstruct it. It is shown that the solvability of this problem requires the availability of a redundant set of outputs. This very problem is instrumental to unveiling the fundamental geometric properties of output-redundant systems, which form the basis for our subsequent constructions and results. As a direct application, we demonstrate how output allocation can be employed to effectively protect the input information from certain output eavesdroppers with guaranteed results.