Monte Carlo approach to the evaluation of the security of device-independent quantum key distribution

TL;DR

This paper develops a Monte Carlo method to evaluate the security of multi-setting device-independent quantum key distribution protocols, providing bounds on key rates and detection efficiencies, advancing secure quantum communication without heralding.

Contribution

Introduces a Monte Carlo approach for security analysis of multi-setting DI-QKD, highlighting how increasing measurement settings can reduce detection efficiency requirements.

Findings

Increasing measurement settings can lower detection efficiency thresholds.

Security bounds depend on the choice of Bell inequalities and experiment symmetry.

The method applies to protocols without heralding, broadening practical DI-QKD scenarios.

Abstract

We present a generic study on the information-theoretic security of multi-setting device-independent quantum key distribution protocols, i.e., ones that involve more than two measurements (or inputs) for each party to perform, and yield dichotomic results (or outputs). The approach we develop, when applied in protocols with either symmetric or asymmetric Bell experiments, yields nontrivial upper bounds on the secure key rates, along with the detection efficiencies required upon the measuring devices. The results imply that increasing the number of measurements may lower the detection efficiency required by the security criterion. The improvement, however, depends on (i) the choice of multi-setting Bell inequalities chosen to be tested in a protocol, and (ii) either a symmetric or asymmetric Bell experiment is considered. Our results serve as an advance toward the quest for evaluating security and reducing efficiency requirement of applying device-independent quantum key distribution in scenarios without heralding.