基于预报单光子源的BB84诱惑态量子密钥分配研究

BB84-decoy-state quantum key distribution with a heralded single photon source

结合预报单光子源的量子密钥分配系统模型,介绍了三种典型的BB84诱惑态方案:主动诱惑态方案,被动诱惑态方案以及主动和被动诱惑态相结合的方案。结合数值仿真深入分析了三种方案在性能、实现难度等方面的优缺点。结论表明被动诱惑态思想可以进一步提高BB84诱惑态方案的密钥生成效率;BB84被动诱惑态方案(AYKI方案)由于无需主动制备诱惑态,所以实现最为简单,密钥分配速度快,且方案性能趋近于无穷诱惑态的理论极限值;主动和被动诱惑态相结合的方案性能虽然稍优于AYKI方案,但是改善空间很小。

Based on the model of quantum key distribution （QKD） system with a heralded single photon source （HSPS）, three typical BB84-decoy-state methods axe introduced including active decoy-state protocol, passive decoy-state protocol and the protocol combining active and passive decoy-state idea. The performance and implementation difficulty of the three decoy-state methods are analyzed with numerical simulation. The results show that the key generation rate of BB84 decoy-state protocol is increased by the passive decoy idea. Passive decoy-state method proposed by Adachi, Yamamoto, Koashi and Imoto （AYKI） is easy to implement and speedy to distribute keys because there is no need to prepare decoy states actively. Furthermore, the performance of the AYKI protocol is close to that of the infinite decoy-state protocol. The performance of the method combining active and passive decoy-state idea is better than that of AYKI protocol, but there is not much room left for improvement after the AYKI protocol is implemented.