Faithful and secure distributed quantum sensing under general-coherent attacks
Year: 2026
Authors: Bizzarri G., Barbieri M., Manrique M., Parisi M., Bruni F., Gianani I., Rosati M.
Autors Affiliation: Univ Roma Tre, Dipartimento Sci, Rome, Italy; CNR, Ist Nazl Ott, Florence, Italy; Univ Roma Tre, Dipartimento Ingn Civile Informat & Tecnol Aeronau, Rome, Italy.
Abstract: Quantum metrology and cryptography can be combined in a distributed and/or remote sensing setting, where distant end-users with limited quantum capabilities can employ quantum states, transmitted by a quantum-powerful provider via a quantum network, to perform quantum-enhanced parameter estimation in a private fashion. Previous works on the subject have been limited by restricted assumptions on the capabilities of a potential eavesdropper and the use of abort-based protocols that prevent a simple practical realization. Here we introduce, theoretically analyze, and experimentally demonstrate single- and two-way protocols for distributed sensing combining several unique and desirable features: (i) a safety-threshold mechanism that allows the protocol to proceed in low-noise cases and quantifying the potential tampering with respect to the ideal estimation procedure, effectively paving the way for wide-spread practical realizations; (ii) equivalence of entanglement-based and mutually-unbiased-bases-based formulations; (iii) robustness against collective attacks via a LOCC-de-Finetti theorem, for the first time to our knowledge. Finally, we demonstrate our protocols in a photonic-based implementation, observing that the possibility of guaranteeing a safety threshold may come at a significant price in terms of the estimation bias, potentially overestimating the effect of tampering in practical settings.
Journal/Review: NPJ QUANTUM INFORMATION
Volume: 12 (1) Pages from: 33-1 to: 33-11
More Information: We thank F. De Stefani for valuable discussion, and A. Fabbri for assistance with malfunctioning equipment. This work was supported by the PRIN project PRIN22-RISQUE-2022T25TR3 of the Italian Ministry of University. G.B. is supported by Rome Technopole Innovation Ecosystem (PNRR grant M4-C2-Inv). IG acknowledges the support from MUR Dipartimento di Eccellenza 2023-2027. M.R. acknowledges support from the project PNRR – Finanziato dall’Unione Europea-MISSIONE 4 COMPONENTE 2 INVESTIMENTO 1.2-Finanziamento di progetti presentati da giovani ricercatori-Id MSCA 0000011-SQUID – CUP F83C22002390007 (Young Researchers)-Finanziato dall’Unione europea – NextGenerationEU.KeyWords: NetworksDOI: 10.1038/s41534-025-01180-0
