We propose a fully passive twin-field quantum key distribution (QKD) setup where basis choice, decoy-state preparation and encoding are all implemented entirely by post-processing without any active modulation. Our protocol can remove the potential side-channels from both source modulators and detectors, and additionally retain the high key rate advantage offered by twin-field QKD, thus offering great implementation security and good performance. Importantly, we also propose a post-processing strategy that uses mismatched phase slices and minimizes the effect of sifting. We show with numerical simulation that the new protocol can still beat the repeaterless bound and provide satisfactory key rate.
@article{arxiv.2304.12062,
title = {Fully-Passive Twin-Field Quantum Key Distribution},
author = {Wenyuan Wang and Rong Wang and H. F. Chau and Hoi-Kwong Lo},
journal= {arXiv preprint arXiv:2304.12062},
year = {2026}
}
Comments
Newly added frequency compensation scheme and preliminary finite-size analysis in the Appendix