Table 1. Figure of merit.

States	Link	Loss (dB)	M±ΔM
BB84	10 m	23.2±2.0	0.0116±0.0005
Fair	10 m	23.2±2.0	0.0082±0.0005
BB84	12.4 km	32.8±2.0	−0.006±0.002
Fair	12.4 km	32.8±2.0	−0.003±0.002

The figure of merit M = P_C* − P* for all cases. The 10-m link cases yield M>0 and cannot be reproduced with classical communication only. The results over the 12.4-km link yield M≈0 (with the fair states, considering uncertainty), and M<0 (with the BB84 states). Hence, with the fair states, our implementation performs neither better nor worse than what is classically possible. Our results with the BB84 states could, however, be reproduced classically. The uncertainty ΔM is statistical and assumes a Poisson distribution of detection events.