Passive Decoy-State Quantum Key Distribution with Coherent Light

Entropy

Marcos Curty¹  Valerio Pruneri²  Morgan W. Mitchell²  Marc Jofre² 

[1] Escuela de Ingeniería de Telecomunicación, Department of Signal Theory and Communications, University of Vigo, Campus Universitario, Vigo 36310, Pontevedra, Spain;ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, Castelldefels 08860, Barcelona, Spain;

关键词: quantum cryptography;    quantum key distribution;    quantum communication;   

DOI  :  10.3390/e17064064

来源: DOAJ

【 摘 要 】

Signal state preparation in quantum key distribution schemes can be realized using either an active or a passive source. Passive sources might be valuable in some scenarios; for instance, in those experimental setups operating at high transmission rates, since no externally driven element is required. Typical passive transmitters involve parametric down-conversion. More recently, it has been shown that phase-randomized coherent pulses also allow passive generation of decoy states and Bennett–Brassard 1984 (BB84) polarization signals, though the combination of both setups in a single passive source is cumbersome. In this paper, we present a complete passive transmitter that prepares decoy-state BB84 signals using coherent light. Our method employs sum-frequency generation together with linear optical components and classical photodetectors. In the asymptotic limit of an infinite long experiment, the resulting secret key rate (per pulse) is comparable to the one delivered by an active decoy-state BB84 setup with an infinite number of decoy settings.

【 授权许可】

Unknown