Long distance quantum key distribution without decoy state

TL;DR

This paper introduces a novel decoy-state free method for quantum key distribution that improves key rates and secure distances, overcoming limitations of existing decoy-state techniques.

Contribution

The authors present the first decoy-state free approach for estimating yield and error rate in BB84, enhancing performance and robustness against dark count deviations.

Findings

Higher key generation rates than decoy state methods

Extended secure communication distances

Robustness to dark count rate deviations

Abstract

We present a method without decoy state to estimate faithfully and efficiently the yield and quantum bit error rate of single photon pulse for BB84 protocol. The numerical calculations show that key generation rate and maximal secure communication distance of our method are better than results of the decoy state method. As we know, it is the first time we present this method and the idea is very novel. Furthermore, our method can overcome the drawbacks of decoy state method. In our method, the maximal secure distance is insensitive to the deviation of dark count rate from exact value.