Finite-key analysis for the 1-decoy state QKD protocol
Davide Rusca, Alberto Boaron, Fadri Grünenfelder, Anthony Martin, Hugo Zbinden · Applied Physics Letters · 2018
It has been shown that in the asymptotic case of infinite-key length, the 2-decoy state Quantum Key Distribution (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 QKD, in most common practical scenarios.