Finite-key analysis on the 1-decoy state QKD protocol

TL;DR

This paper provides a finite-key analysis of the 1-decoy state QKD protocol, showing it outperforms the 2-decoy protocol in practical scenarios with finite data sizes, making it more suitable for real-world applications.

Contribution

The paper introduces a finite-key security analysis for the 1-decoy protocol, demonstrating its advantages over the 2-decoy protocol in practical settings.

Findings

1-decoy protocol achieves higher secret key rates for block sizes up to 10^8 bits.

1-decoy protocol is easier to implement than 2-decoy protocol.

For most experimental conditions, 1-decoy outperforms 2-decoy in finite-key scenarios.

Abstract

It has been shown that in the asymptotic case of infinite-key length the 2-decoy state QKD protocol outperforms the 1-decoy state protocol. Here, we present a finite-key analysis of the 1-decoy method. Interestingly, we find that for practical block sizes of up to $10^8$ bits, the 1-decoy protocol achieves for almost all experimental settings higher secret key rates than the 2-decoy protocol. Since using only one decoy is also easier to implement, we conclude that it is the best choice for practical QKD.