Quantum cryptographic conferencing (QCC) allows sharing secret keys among multiple distant users and plays a crucial role in quantum networks. Because of the fragility and low generation rate of genuine multipartite entangled states required in QCC, realizing and extending QCC with the entanglement-based protocol is challenging. Measurement-device-independent (MDI) QCC, which removes all detector side channels, is a feasible long-distance quantum communication scheme to practically generate multipartite correlation with multiphoton projection measurement. Here we experimentally realize the three-user MDIQCC protocol with four-intensity decoy-state method, in which we employ the polarization encoding and the Greenberger-Horne-Zeilinger state projection measurement. Our work demonstrates the experimental feasibility of the MDI QCC, which lays the foundation for the future realization of quantum networks with multipartite communication tasks.
@article{arxiv.2411.14890,
title = {Experimental Measurement-Device-Independent Quantum Cryptographic Conferencing},
author = {Yifeng Du and Yufeng Liu and Chengdong Yang and Xiaodong Zheng and Shining Zhu and Xiao-song Ma},
journal= {arXiv preprint arXiv:2411.14890},
year = {2025}
}