Effect of detector dead times on the security evaluation of differential-phase-shift quantum key distribution against sequential attacks

摘要

We investigate limitations imposed by detector dead times on the performance of sequential attacks against a differential-phase-shift (DPS) quantum key distribution (QKD) protocol with weak coherent pulses. In particular; we analyze sequential attacks based on unambiguous state discrimination of the signal states emitted by the source and we obtain ultimate upper bounds on the maximal distance achievable by a DPS QKD scheme both for the case of calibrated and uncalibrated devices, respectively.