RT Journal Article
T1 Practical decoy-state method for twin-field quantum key distribution
A1 Grasselli, Federico
A1 Curty Alonso, Marcos
K1 3311.04 Dispositivos Electroópticos
K1 2209.10 láseres
K1 2212.11 Fotones
AB Twin-field (TF) quantum key distribution (QKD) represents a novel QKD approach whose principal merit is to beat the point-to-point private capacity of a lossy quantum channel, thanks to performing single-photon interference in an untrusted node. Indeed, recent security proofs of various TF-QKD type protocols have confirmed that the secret key rate of these schemes scales essentially as the square root of the transmittance of the channel. Here, we focus on the TF-QKD protocol introduced by Curty et al, whose secret key rate is nearly an order of magnitude higher than previous solutions. Its security relies on the estimation of the detection probabilities associated to various photon-number states through the decoy-state method. We derive analytical bounds on these quantities assuming that each party uses either two, three or four decoy intensity settings, and we investigate the protocol's performance in this scenario. Our simulations show that two decoy intensity settings are enough to beat the point-to-point private capacity of the channel, and that the use of four decoys is already basically optimal, in the sense that it almost reproduces the ideal scenario of infinite decoys. We also observe that the protocol seems to be quite robust against intensity fluctuations of the optical pulses prepared by the parties.
PB New Journal of Physics
SN 13672630
YR 2019
FD 2019-07-01
LK http://hdl.handle.net/11093/3202
UL http://hdl.handle.net/11093/3202
LA eng
NO New Journal of Physics, 21, 073001 (2019)
NO Agencia Estatal de Investigación | Ref. TEC2017-88243-R
DS Investigo
RD 08-oct-2024