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 108 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.
@article{arxiv.1801.03443,
title = {Finite-key analysis on the 1-decoy state QKD protocol},
author = {Davide Rusca and Alberto Boaron and Fadri Grünenfelder and Anthony Martin and Hugo Zbinden},
journal= {arXiv preprint arXiv:1801.03443},
year = {2018}
}