Security of high speed quantum key distribution with finite detector dead time

摘要: The security of a high speed quantum key distribution system with finite detector dead time τ is analyzed. When the transmission rate becomes higher than maximum count individual detectors (1/τ), issues affect scheme for sifting bits. Analytical calculations and numerical simulations Bennett-Brassard BB84 protocol are performed. We study Rogers et al.'s (further information available in [D. J. Rogers, C. Bienfang, A. Nakassis, H. Xu, W. Clark, New Phys. 9, 319 (2007)]) presence an active eavesdropper Eve who has power to perform intercept-resend attack. It shown that no longer guaranteed be secure. More specifically, can induce basis-dependent detection efficiency at receiver's end. Modified schemes basis-independent thus secure then introduced. analyze compare these this scenario, calculate simulate their generation rate. 1/(2τ) passive basis selection, 1/τ selection. analysis also extended decoy state one particular scheme.