【摘要】 基于实际量子密钥分配系统中所使用的强衰减的激光脉冲并不是单光子,量子密钥分配的信道不是无损耗的,窃听者的技术能力也不是无限的这些具体问题,采用了分束窃听与截获重发窃听策略相结合的方案讨论了窃听问题并给出了合法用户在筛选后的密钥中所能容忍的误码率上限更多还原

【Abstract】 Practical implementations of quantum key distribution systems use attenuated laser pulses as the signal source rather than single photons. The channels used to transmit are lossy. On the basis of above two points, a combining eavesdropping strategy of intercept resend and beamsplitting is discussed in terms of eavesdropper′s technology requirement. At last, a maximum disturbance bound is derived for a given mean photon number and transmission length. Eavesdropper can be detected with the bound.更多还原