Improved statistical fluctuation analysis for measurement-device-independent quantum key distribution with three-intensity decoy-state method

TL;DR

This paper introduces an improved statistical fluctuation analysis method for measurement-device-independent quantum key distribution using a three-intensity decoy-state approach, significantly enhancing key rates over previous methods.

Contribution

It presents a joint statistical fluctuation analysis that tightens key quantity formulas, leading to substantial improvements in secure key rates at long distances.

Findings

Key rate improves by about 97% at 50 km

Key rate improves by 146% at 100 km

Method outperforms traditional fluctuation treatments

Abstract

We present an improved statistical fluctuation analysis for measurement device independent quantum key distribution with three-intensity decoy-state method. Taking the statistical fluctuations for different sources jointly, we present more tightened formulas for some key quantities used in calculating the secure final key. Numerical simulation shows that, given the total number of pulses $10^{12}$, our method improves the key rate by about 97\% for a distance of 50kms compared with the result given by Xu., et al. (Phys. Rev. A 89, 052333); and improves the key rate by $146\%$ for a distance of 100kms compared with the result from full optimization of all parameters but treating the statistical fluctuations traditionally, i.e., treating the fluctuations for different sources separately.