Schematic diagram of a quantum sensor network. Unknown parameters are spatially distributed throughout the network. Metrically, the goal is to estimate functions of these parameters, such as the mean. The concept of privacy is also addressed to protect against malicious enemies. Credit: Hassani et al.
Devices that utilize quantum mechanics effects are widely referred to as quantum technology, and thus help you tackle some real problems faster and more efficiently. In recent years, physicists and engineers have introduced a variety of promising quantum technologies, including so-called quantum sensors.
A network of quantum sensors can theoretically be used to measure certain parameters with significant accuracy. These networks utilize quantum phenomena known as entanglement, which involves persistent connections between particles, allowing them to share information instantly with each other, even in the distance.
Quantum Sensor Networks (QSNs) may have a variety of advantageous real-world applications, but their effective deployment is that information shared between sensors is private and malicious third parties. It also relies on its ability to ensure that it is inaccessible.
In a paper published in a physical review letter, researchers at Sorbonne University are introducing new protocols that help to enhance privacy of information shared between networked quantum sensors.
“Network sensing represents a promising research pathway in the broader field of quantum sensing,” Majid Hasani, the first author of the paper, told Phys.org. “Given the inevitable presence of malicious enemies that intercept quantum channels to obtain some information, we have set out to devise a private protocol that can estimate unknown parameters without any information being lost.”
The new protocol, devised by Hasani and his colleagues, relies on an established mathematical tool known as the Quantum Fisher Information Matrix (QFIM). This matrix essentially quantifies the accuracy of parameter estimates related to a quantum measurement device or process.
“QFIM is a well-known amount in the field of quantum measurement and sensing, quantifying the maximum amount of extractable information about known parameters across all possible measurements and setting the lower limit with the accuracy of the estimation. “We’ll do that,” explained Hasani.
“The mathematical properties of this matrix, such as the continuity relationship between entries, allowed us to construct a private protocol.”
Essentially, Hasani and his colleagues’ proposed protocol involves manipulating QFIM to identify the quantum state of a quantum sensor network that maximizes privacy. Their paper also introduced the idea of Quasiprivacy (𝜀-Privacy). This is a measure of how close the quantum state is to ensure “full privacy.”
To illustrate the potential of the protocol, researchers provided examples of how it could be applied to a network of quantum sensors. In the example they outlined, the quantum sensor network specifically estimated the average of unknown parameters, and the team showed how the protocol promotes privacy.
“The presented methods provide a systematic way to build a protocol that includes tunable extractable information from the network,” Hasani said. “This adjustability allows us to control information leakage and thereby protect information from malicious enemies.”
So far, the newly proposed privacy protocol has only been demonstrated in theory, but Hasani and his colleagues hope to implement it soon and test it in an experimental setting . In the future, their efforts could contribute to achieving safe quantum sensing and communication.
“The next step is to implement the protocol experimentally,” Hasani added. “This ongoing project with collaborators is essential for the development of actual quantum sensors.”
More information: Majid Hassani et al., Quantum Sensor Network Privacy, Physics Review Letter (2025). doi: 10.1103/physrevlett.134.030802. on arxiv: doi: 10.48550/arxiv.2408.01711
©2025 Science X Network
Quote: Newly proposed protocol for increasing privacy in quantum sensor networks, obtained from February 15, 2025, https://phys.org/2025-02 (February 15, 2025)
This document is subject to copyright. Apart from fair transactions for private research or research purposes, there is no part that is reproduced without written permission. Content is provided with information only.
