Long-Distance Decoy-State Quantum Key Distribution in Optical Fiber

National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305(Dated: Submitted 26 July 2006)The theoretical existence of photon-number-splitting attacks creates a security loophole for most quantumkey distribution (QKD) demonstrations that use a highly attenuated laser source. Using ultra-low-noise, high-efficiency transition-edge sensor photo-detectors, we have implemented the first version of a decoy stateprotocolthat incorporates finitestatisticswithout theuse of Gauss ian approximations ina one-way QKD system, enablingthe creation of secure keys immune to photon-number-splitting attacks and highly resistant to Trojan horseattacks over 107 km of optical fiber.