Quantum-private distributed sensing

TL;DR

This paper demonstrates a quantum protocol for private distributed sensing using a three-photon GHZ state, achieving high-precision global parameter estimation while maintaining local data confidentiality, advancing secure quantum network applications.

Contribution

The work implements a quantum private parameter estimation protocol with a three-photon GHZ state, achieving Heisenberg-limited precision and enhanced privacy in distributed quantum sensing.

Findings

Achieved Heisenberg-limited precision scaling.

Suppressed local parameter information by up to three orders of magnitude.

Verified privacy and precision bounds using stabilizer measurements.

Abstract

Quantum networks can enhance both security and privacy conditions for multi-user communication, delegated computation, and distributed sensing tasks. An example quantum protocol is private parameter estimation (PPE) where only the aggregate information is accessible while individual sensor data remain confidential. Specifically, the protocol enables the estimation of a global function of remote sensor parameters without revealing local parameters to any entity. We implement the PPE protocol by distributing a three-photon Greenberger-Horne-Zeilinger (GHZ) state, among three sensors, which is verified using stabilizer measurements to establish privacy and precision bounds for the sensing task. We demonstrate Heisenberg-limited precision scaling of the global parameter while suppressing the metrological information of the local parameters by up to three orders of magnitude. This work, which integrates privacy in distributed quantum sensing, marks a crucial step towards developing advanced quantum-secure-and-private protocols in complex quantum networks.