We present a secure network communication system that operated with decoy-state quantum cryptography in a real-world application scenario. The full key exchange and application protocols were performed in real time among three nodes, in which two adjacent nodes were connected by approximate 20 km of commercial telecom optical fiber. The generated quantum keys were immediately employed and demonstrated for communication applications, including unbreakable real-time voice telephone between any two of the three communication nodes, or a broadcast from one node to the other two nodes by using one-time pad encryption.
@article{arxiv.0810.1264,
title = {Field test of a practical secure communication network with decoy-state quantum cryptography},
author = {Teng-Yun Chen and Hao Liang and Yang Liu and Wen-Qi Cai and Lei Ju and Wei-Yue Liu and Jian Wang and Hao Yin and Kai Chen and Zeng-Bing Chen and Cheng-Zhi Peng and Jian-Wei Pan},
journal= {arXiv preprint arXiv:0810.1264},
year = {2009}
}