The theoretical existence of photon-number-splitting attacks creates a security loophole for most quantum key distribution (QKD) demonstrations that use a highly attenuated laser source. Using ultra-low-noise, high-efficiency transition-edge sensor photodetectors, we have implemented the first version of a decoy-state protocol that incorporates finite statistics without the use of Gaussian approximations in a one-way QKD system, enabling the creation of secure keys immune to photon-number-splitting attacks and highly resistant to Trojan horse attacks over 107 km of optical fiber.
@article{arxiv.quant-ph/0607186,
title = {Long distance decoy state quantum key distribution in optical fiber},
author = {Danna Rosenberg and Jim W. Harrington and Patrick R. Rice and Philip A. Hiskett and Charles G. Peterson and Richard J. Hughes and Adriana E. Lita and Sae Woo Nam and Jane E. Nordholt},
journal= {arXiv preprint arXiv:quant-ph/0607186},
year = {2007}
}