Long-distance entanglement-based quantum key distribution experiment using practical detectors.
We report an entanglement-based quantum key distribution experiment that we performed over 100 km of optical fiber using a practical source and detectors. We used a silicon-based photon-pair source that generated high-purity time-bin entangled photons, and high-speed single photon detectors based on InGaAs/InP avalanche photodiodes with the sinusoidal gating technique. To calculate the secure key rate, we employed a security proof that validated the use of practical detectors. As a result, we confirmed the successful generation of sifted keys over 100 km of optical fiber with a key rate of 4.8 bit/s and an error rate of 9.1%, with which we can distill secure keys with a key rate of 0.15 bit/s.
Takesue
Hiroki
H
NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa, 243-0198, Japan. htakesue@will.brl.ntt.co.jp
Harada
Ken-Ichi
K
Tamaki
Kiyoshi
K
Fukuda
Hiroshi
H
Tsuchizawa
Tai
T
Watanabe
Toshifumi
T
Yamada
Koji
K
Itabashi
Sei-Ichi
S
D016494:Computer Security / Q000295:instrumentation; D003198:Computer Simulation; D004867:Equipment Design; D005336:Fiber Optic Technology / Q000295:instrumentation*; D055100:Optical Fibers; D017785:Photons; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*