The quantum cryptographic conferencing (QCC) protocol, which distributes identical secure keys to user groups, is a crucial component of the quantum network. Previous experimental works have implemented the measurement-device-independent (MDI) QCC, of which the key rate in an N-user network scales down as R∼O(ηN), respectively. Building on the MDI QCC protocol, the asynchronous MDI (AMDI) QCC protocol theoretically integrates the mode pairing scheme into QCC, significantly boosting the key rate to R∼O(η), which is independent of the number of users, and thus demonstrating greater application potential. Experimentally, in this work, we implement the three-user AMDI QCC network without global phase tracking by adopting the fast Fourier transform-based frequency difference estimation and the phase drift compensation technique. Finally, we achieve a key rate of about 4.470×10−9 bits per pulse under a maximum overall loss of about 59.6 dB. This work provides a scalable solution for the development of large-scale quantum communication networks in the future.
@article{arxiv.2602.20927,
title = {Experimental Asynchronous Measurement-Device-Independent Quantum Cryptographic Conferencing},
author = {Yifeng Du and Yang Hu and Yufeng Liu and Wenhan Yan and Jinghao Zhang and Shining Zhu and Xiao-Song Ma},
journal= {arXiv preprint arXiv:2602.20927},
year = {2026}
}