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Long-distance entanglement-based quantum key distribution over optical fiber



Toshimori Honjo, Sae Woo Nam, Hiroki Takesue, Qiang Zhang, H. Kamada, Y. Nishida, O. Tadanaga, M. Asobe, Burm Baek, Robert Hadfield, Shigehito Miki, Mikio Fujiwara, Masahide Sasaki, Z. Wang, K. Inoue, Yoshihisa Yamamoto


We report the first entanglement-based quantum key distribution (QKD) experiment over a 100-km optical fiber. We used superconducting single photon detectors based on NbN nanowires that provide high-speed single photon detection for the 1.5-υm telecom band, an efficient entangled photon pair source that consists of a fiber coupled periodically poled lithium niobate waveguide and ultra low loss filters, and planar lightwave circuit Mach-Zehnder interferometers (MZIs) with ultra stable operation. These characteristics enabled us to perform an entanglement-based QKD experiment over a 100-km optical fiber. In the experiment, which lasted approximately 8 hours, we successfully generated a 16 kbit sifted key with a quantum bit error rate of 6.9 % at a rate of 0.59 bits per second, from which we were able to distill a 3.9 kbit secure key.
Optics Express


Quantum key distribution, QKD, Superconducting single-photon detector, SSPD, entanglement


Honjo, T. , Nam, S. , Takesue, H. , Zhang, Q. , Kamada, H. , Nishida, Y. , Tadanaga, O. , Asobe, M. , Baek, B. , Hadfield, R. , Miki, S. , Fujiwara, M. , Sasaki, M. , Wang, Z. , Inoue, K. and Yamamoto, Y. (2008), Long-distance entanglement-based quantum key distribution over optical fiber, Optics Express, [online], (Accessed January 23, 2022)
Created November 9, 2008, Updated October 12, 2021