Figure 3
From: Performing private database queries in a real-world environment using a quantum protocol

Histograms for the information gained by the user in the 104 queries performed in the µ = 9.5 ± 0.47 case.
(a) The number of bits learned by the user. (b) The percentage of the database of which the user learns significant partial information. In both figures error bars for the experimental results represent one standard deviation assuming Poissonian counting statistics and the blue crosses show the expected distribution obtained from Monte Carlo simulations.