# Device-Independent Quantum Private Query Protocol without the Assumption of Perfect Detectors

## TL;DR

This paper analyzes the security of a device-independent quantum private query protocol under imperfect detectors and proposes a more practical protocol that maintains security without assuming perfect detectors.

## Contribution

It identifies security vulnerabilities in the MRT17 protocol with imperfect detectors and introduces a new, more practical device-independent QPQ protocol that does not rely on perfect detectors.

## Key findings

- MRT17 protocol is vulnerable under imperfect detectors
- Proposed protocol remains secure without perfect detector assumption
- Enhances practicality of device-independent quantum private query

## Abstract

The first device-independent quantum private query protocol (MRT17) which is proposed by Maitra \emph{et al.} [Phys. Rev. A 95, 042344 (2017)] to enhance the security through the certification of the states and measurements. However, the MRT17 protocol works under an assumption of perfect detectors, which increases difficulty in the implementations. Therefore, it is crucial to investigate what would affect the security of this protocol if the detectors were imperfect. Meanwhile, Maitra \emph{et al.} also pointed out that this problem remains open. In this paper, we analyze the security of MRT17 protocol when the detectors are imperfect and then find that this protocol is under attack in the aforementioned case. Furthermore, we propose device-independent QPQ protocol without the assumption of perfect detectors. Compared with MRT17 protocol, our protocol is more practical without relaxing the security in the device-independent framework.