关键词: 量子密钥分配, 诱骗态, 测量设备无关, 自发参量下转换源, 统计涨落

Abstract: Parameter estimation(the yield and the phase error rate of the single photon) is a major factor that affects the key rate of decoy state MDI-QKD. This paper investigates the issues of parameter estimation in MDI-QKD with a spontaneous parametric down conversion (SPDC) source with a joint estimation method. Different from the existing separate estimation method, we derive analytical solutions to the parameters from the equation set of the average count rate and error rate, and then analyze it as a unitary function conceding the relevance between the two parameters. Through looking at the minimum of the function in the closed interval, a tighter estimation of the secure key rate is obtained. This method provides a new way to increase the performance of the MDI-QKD protocol.

Key words: Quantum Key Distribution, decoy state, Measurement Device-Independent, Spontaneous Parametric Down Conversion Source, statistical fluctuation