Quantum conference key agreement (CKA) enables key sharing among multiple trusted users with information-theoretic security. Currently, the key rates of most quantum CKA protocols suffer from the limit of the total efficiency among quantum channels. Inspired by the coherent one-way and twin-field quantum key distribution (QKD) protocols, we propose a quantum CKA protocol of three users. Exploiting coherent states with intensity 0 and $\mu$ to encode logic bits, our protocol can break the limit. Additionally, the requirements of phase randomization and multiple intensity modulation are removed in our protocol, making its experimental demonstration simple.

翻译：量子会议关键协议(CKA)允许多个信任的用户在信息理论安全下进行关键共享。 目前,大多数量子 CKA协议的关键比率受量子频道总效率的限制影响。 在一致的单向和双向量子键分配协议(QKD)的启发下,我们提出了一个由三个用户组成的量子 CKA协议。利用强度为0和$=mu$的一致状态来编码逻辑比特,我们的协议可以打破这一限制。此外,我们的协议取消了分阶段随机化和多强度调制的要求,使其实验性示范简单化。