Fig. 3: Finite key efficiency vs source rate.
From: Finite key performance of satellite quantum key distribution under practical constraints
Source rate normalised secret key length (SKL) as a function of fs for overpasses with \({\theta }_{\max }=9{0}^{\circ }\) (solid lines) and 30∘ (dashed lines), for three system configurations {QBERI, pec}: A = {0.1%, 1 × 10−8}, B = {0.5%, 1 × 10−8}, and D = {0.5%, 1 × 10−7}. The critical fs value corresponds to the transition of zero and non-zero finite SKL. The shaded blue region illustrates the key suppression region for System A with \({\theta }_{\max }=9{0}^{\circ }\) where statistical fluctuations in estimated parameters overwhelm key generation due to finite available statistics. The vertical line is at fs = 500 MHz, which we consider for the remainder of the paper.
