Device-independent quantum key distribution provides security even when the equipment used to communicate over the quantum channel is largely uncharacterized. An experimental demonstration of device-independent quantum key distribution is however challenging. A central obstacle in photonic implementations is that the global detection efficiency, i.e., the probability that the signals sent over the quantum channel are successfully received, must be above a certain threshold. We here propose a method to significantly relax this threshold, while maintaining provable device-independent security. This is achieved with a protocol that adds artificial noise, which cannot be known or controlled by an adversary, to the initial measurement data (the raw key). Focusing on a realistic photonic setup using a source based on spontaneous parametric down conversion, we give explicit bounds on the minimal required global detection efficiency.
@article{arxiv.2005.13015,
title = {Noisy pre-processing facilitating a photonic realisation of device-independent quantum key distribution},
author = {M. Ho and P. Sekatski and E. Y. -Z. Tan and R. Renner and J. -D. Bancal and N. Sangouard},
journal= {arXiv preprint arXiv:2005.13015},
year = {2020}
}