Quantum fingerprinting using two-photon interference

TL;DR

This paper introduces a quantum fingerprinting protocol using two-photon interference that does not require shared phase references, achieving similar advantages to existing schemes while analyzing real-world imperfections.

Contribution

The paper proposes a novel quantum fingerprinting protocol based on two-photon interference without shared phase references, extending previous work on coherent pulse schemes.

Findings

Protocol scales similarly to coherent pulse schemes in classical information transmission.

Performance is affected by photon statistics, transmission losses, dark counts, and distinguishability.

Chernoff information quantifies the impact of imperfections on protocol performance.

Abstract

We present a quantum fingerprinting protocol relying on two-photon interference which does not require a shared phase reference between the parties preparing optical signals carrying data fingerprints. We show that the scaling of the protocol, in terms of transmittable classical information, is analogous to the recently proposed and demonstrated scheme based on coherent pulses and first-order interference, offering comparable advantage over classical fingerprinting protocols without access to shared prior randomness. We analyze the protocol taking into account non-Poissonian photon statistics of optical signals and a variety of imperfections, such as transmission losses, dark counts, and residual distinguishability. The impact of these effects on the protocol performance is quantified with the help of Chernoff information.