Quantum-secured covert sensing for the Doppler effect

Quantum mechanics has paved the way for establishing shared privacy among communicating parties through a secure regime known as quantum-secured communication. Recent advancements in both theory and experimentation have unveiled the potential of quantum resources in enhancing the performance and security of estimating unknown parameters. This has led to the emergence of a novel paradigm known as quantum-secured covert sensing, wherein the sensing operation is concealed from an adversary monitoring the environment by embedding the probe signal in a bright noise background. The performance and security of such protocols are quantified using quantum measurement theory. While previous investigations into quantum-secured covert sensing primarily focused on proof-of-concept phase estimation problems, this paper presents a pioneering quantum-secured covert sensing system designed for the Doppler effect - a versatile estimation problem with broad applications. Our research uncovers an inherent trade-off among measurement precision, security, and range within the system. This work establishes a new avenue for incorporating physical-layer security into sensing systems, thereby opening up exciting possibilities for future research in this field.