Physical Layer Security for Sensing-Communication-Computing-Control Closed Loop: A Systematic Security Perspective

TL;DR

This paper proposes a systematic physical layer security approach for the entire sensing-communication-computing-control closed loop in industrial automation, optimizing resource allocation to maximize security and performance.

Contribution

It introduces a new metric, closed-loop negentropy, and develops a globally optimal joint design method for secure resource allocation in the SC3 closed loop.

Findings

Systematic PLS approach outperforms link-level designs.

Joint optimization enhances overall security and performance.

Simulation confirms the effectiveness of the proposed method.

Abstract

In industrial automation or emergency rescue, sensors and robots work together with the help of an edge information hub (EIH) containing both communication and computing modules. Typically, the EIH collects the sensing data via the sensor-to-EIH link, processes data and then makes decisions on board before sending commands to the robot via the EIH-to-robot link. This forms a sensing-communication-computing-control (SC3) closed loop. In practice, the inherent openness of wireless links within the closed loop leads to susceptibility to eavesdropping. To this end, this paper refines the conventional physical layer security (PLS) approach with a systematic thinking to safeguard the SC3 closed loop. The closed-loop negentropy (CNE), a new metric for the performance of the whole SC3 closed loop, is maximized under the closed-loop security constraint. The transmit time, power, bandwidth of both wireless links, and the computing capability, are jointly designed. The optimization problem is non-convex. We leverage the Karush-Kuhn-Tucker (KKT) conditions and the monotonic optimization (MO) theory to derive its globally optimal solution. Simulation results show the performance gain of the proposed systematic approach, and reveal the advantage of exploiting the closed-loop structure-level PLS over the link-level or sum-link-level designs.