Fig. 6: Conditional minimum entropy H_min(A∣E) as a function of the sampling length with the finite size (FS) and infinite length (IL).

FZ and IL represent the rates without the afterpulse, and FZP and ILP represent the rates with the afterpulse \({\hat{p}}_{\alpha }=5 \%\). Assume that pulses with coherent states contain ν = 10 photons.