对两种点到多点量子密钥分配系统的密钥生成效率和传输距离进行了分析,讨论了系统的 参数选取对它们的影响。分 析了诱惑态技术对这两种多用户系统的传输距离及密钥生成效率的影响。数据表明,结合诱惑态技术,可以将密钥传 输距离扩展为原来的2倍,以及将量子密钥分发效率提高1个数量级。对点到多点系统进行了功能扩展研究,提出了 可实现任意两用户间密钥共享的协议。该协议无需其它的硬件要求,易于实现。

The quantum key generation efficiency and the transmission distances of two kinds of point-to-multi-point quantum key distribution (QKD) system are discussed. How to select the devices’ parameters is considered detailedly when designing a multi-user QKD system. Decoy state techniques can enhance the security of point-to-multi-point QKD systems, for example, the transmission distance is extended two times and the quantum key generation efficiency is improved a factor of ten. Based on point-to-multi-point QKD systems, a protocol which can realize secret key sharing between two arbitrary receivers is proposed.