Security and gain improvement of a practical quantum key distribution using a gated single-photon source and probabilistic photon-number resolution
Tomoyuki Horikiri, Hideki Sasaki, Haibo Wang, Takayoshi Kobayashi · Physical Review A · 2005
We propose a high security quantum key distribution (QKD) scheme utilizing one mode of spontaneous parametric downconversion gated by a photon number resolving detector. This photon number measurement is possible by using single-photon detectors operating at room temperature and optical fibers. By post selection, the multiphoton probability in this scheme can be reduced to lower than that of a scheme using an attenuated coherent light resulting in improvement of security. Furthermore, if distillation protocol (error correction and privacy amplification) is performed, the gain will be increased. Hence a QKD system with higher security and bit rate than the laser-based QKD system can be attained using present available technologies.