We present our approach for sharing photons and assessing resultant four-photon visibility between two distant parties using concatenated entanglement swapping. In addition we determine the corresponding key generation rate and the quantum bit-error rate. Our model is based on practical limitations of resources, including multipair parametric down-conversion sources, inefficient detectors with dark counts and lossy channels. Through this approach, we have found that a trade-off is needed between experimental run-time, pair-production rate and detector efficiency. Concatenated entanglement swapping enables huge distances for quantum key-distribution but at the expense of low key generation rate.
@article{arxiv.1610.04828,
title = {Long-distance quantum key distribution using concatenated entanglement swapping with practical resources},
author = {Aeysha Khalique and Barry C. Sanders},
journal= {arXiv preprint arXiv:1610.04828},
year = {2017}
}