一种新的预报单光子源诱骗态量子密钥分发方案

提出一种新的预报单光子源诱骗态量子密钥分发方案.在发端采用参量下变换产生纠缠光子对，其中之一用来进行预报探测，根据探测结果将另一路光脉冲分成两个集合，其中预报探测有响应的脉冲集合用作信号态，无响应的脉冲集合作为诱骗态.由于探测效率的问题，这两个集合都是有光子的，通过这两个集合的通过率和错误率估计出单光子的通过率和错误率.此方法不需要改变光强，简单可行.仿真结果表明：该方法可以达到完美单光子源的安全通信距离；与预报单光子源的量子密钥分发相比，密钥产生率有了很大的提高；和三强度预报单光子源诱骗态量子密钥分发的 关键词： 量子保密通信 量子密钥分发 诱骗态 预报单光子源

New method of decoy state quantum key distribution with a heralded single-photon source

We propose a new method of decoy state quantum key distribution with a heralded single-photon source. Alice uses the parametric down-conversion to generate entangled photon-pairs, one of the pair is used as heralding photon. According to the results of the trigger detector the heralded photons are divided into trigger and non-trigger sets.The states of the photons in the trigger set are used as the signal states and the ones in the non-trigger sets are used as the decoy states. Because of the efficiency of the trigger detector, the two sets both have photons. The yield and error rate of the single-photon are estimated through the yield and error rate of the two sets. This method does not need changing the intensity of the photon source, is easy to implement. Analysis results show that this method can reach the same security distance as with a perfect single photon source; the key generation rate is increased a lot compared with the method with a heralded photon source and is approximately two thirds the rate of the three intensities decoy state quantum key distribution with a heralded photon source.