DIFFERENTIAL PHASE SHIFT KEYING QUANTUM KEY DISTRIBUTION

Differential phase shift (DPS) quantum key distribution (QKD) is provided, where the average number of photons per transmitted pulse is predetermined such that the secure key generation rate is maximal or nearly maximal, given other system parameters. These parameters include detector quantum efficiency, channel transmittance and pulse spacing (or clock rate). Additional system parameters that can optionally be included in the optimization include baseline error rate, sifted key error rate, detector dead time, detector dark count rate, and error correction algorithm performance factor. The security analysis leading to these results is based on consideration of a hybrid beam splitter and intercept-resend attack.