【摘要】 针对低轨卫星-地面站间量子密钥分配的光束分离器窃听问题,分析了泊松分布单光子源,建立了量子比特率理论模型,给出了光束分离器窃听中窃听率的表达式.从而分析了低轨卫星-地面站间量子密钥分配的光束分离器窃听问题.结果表明,对于低轨卫星-地面站间链路,每个脉冲平均光子数可以取最优值,窃听率在10-4量级.通过数据纠错和保密加强,可以使得窃听者所获得的密钥信息量降低到1比特以下.这说明,在低轨卫星-地面站间进行量子密钥分配是可行的,在保证系统具有很高量子比特率的同时,量子密钥分配仍然是安全的.更多还原

【Abstract】 In order to avoid beam splitter( BS) eavesdropping problem during quantum key distribution between a ground station and a satellite in a low earth orbit,the single-photon sources with Poisson distribution are analyzed,the theoretical model of quantum bit rate is established and the expression of eavesdropping ratio in BS eavesdropping is given. The BS eavesdropping is analyzed for quantum key distribution between a ground station and a satellite in a low earth orbit. The results show that mean photon number per pulse can be optimized and that eavesdropping ratio is on the order of 10- 4,and by error detection and privacy amplification,the information gained by an eavesdropper can be reduced to less than 1 bit. This means that it is feasible to implement quantum key distribution between a ground station and a satellite in a low earth orbit. Security can be guaranteed in a high quantum bit exchanging rate system.更多还原