SECURE USE OF A SINGLE SINGLE-PHOTON DETECTOR IN A QKD SYSTEM

摘要

A method of using a single single-photon detector (SPD) (232) in a quantum key distribution (QKD) system (101, 201) is described. The method includes modulating a phase of a quantum signal (PA, PB) a first time at a first QKD station (ALICE) by applying a first phase modulation randomly selected from a set of four possible phase modulations. The method also includes modulating the phase of the quantum signal a second time at a second QKD station (BOB). The second modulation involves applying a second phase modulation randomly selected from the same set of four possible phase modulations at the first QKD station. The method is a modification of the BB84 protocol and represents a higher level of quantum security than either the BB84 or B92 protocols when using a QKD system with a single SPD.