Flexible quantum private queries based on quantum key distribution

TL;DR

This paper introduces a flexible, loss-tolerant quantum private query protocol based on quantum key distribution that allows adjustable security and efficiency parameters, improving practicality and control over prior methods.

Contribution

It proposes a novel, adjustable quantum private query protocol that enhances flexibility, security, and efficiency compared to existing quantum key distribution-based methods.

Findings

Protocol is loss tolerant and practical.

Adjustable parameters allow control over security and efficiency.

Lower complexity achieved with certain parameter choices.

Abstract

We present a flexible quantum-key-distribution-based protocol for quantum private queries. Similar to M. Jakobi et al's protocol [Phys. Rev. A 83, 022301 (2011)], it is loss tolerant, practical and robust against quantum memory attack. Furthermore, our protocol is more flexible and controllable. We show that, by adjusting the value of $\theta$, the average number of the key bits Alice obtains can be located on any fixed value the users wanted for any database size. And the parameter $k$ is generally smaller (even $k=1$ can be achieved) when $\theta<\pi/4$, which implies lower complexity of both quantum and classical communications. Furthermore, the users can choose a smaller $\theta$ to get better database security, or a larger $\theta$ to obtain a lower probability with which Bob can correctly guess the address of Alice's query.