Closing the gap of secure quantum key rate with the Heralded Pair-Coherent States

TL;DR

This paper demonstrates that using Heralded Pair Coherent States in quantum key distribution protocols can bridge the long-standing gap in key rates between different photon source implementations, achieving optimal rates across distances.

Contribution

It introduces Heralded Pair Coherent States as a universal photon source that fills the key rate gap in quantum cryptography protocols like BB84 and SARG.

Findings

Heralded Pair Coherent States improve key rates in quantum cryptography.

The approach achieves optimal key rates across various transmission distances.

It unifies the performance of different photon source implementations.

Abstract

In this paper, we investigate the long-standing gap of quantum key rate between the Weak Coherent Pulse (WCP) and Heralded Single Photon Sources(HSPS) implementation of quantum cryptographical protocol. We prove that, by utilizing the Heralded Pair Coherent State (HPCS) photon sources, such a gap can be actually filled in both BB84 and SARG quantum key distribution. Thus, a universal photon source which achieves the up-to-date optimal key rate for each transmission distance is obtained.