We prove the security of a high-capacity quantum key distribution protocol over noisy channels. By using entanglement purification protocol, we construct a modified version of the protocol in which we separate it into two consecutive stages. We prove their securities respectively and hence the security of the whole protocol.
@article{arxiv.quant-ph/0512231,
title = {Proof of Security of a High-Capacity Quantum Key Distribution Protocol},
author = {Xiao-Wei Zhang and Kai Wen and Gui Lu Long},
journal= {arXiv preprint arXiv:quant-ph/0512231},
year = {2007}
}