The present application belongs to the technical field of commercial
cipher system test, and particularly relates to a method for detecting the quality of an entropy source of a commercial
cipher system based on a
quantum random
number generator, which comprises: obtaining
shot noise of an optical
quantum detector at a high sampling rate, removing
direct current bias by using sliding average subtraction, and obtaining a
quantum fluctuation sequence with
zero mean; obtaining a correlation degree by using nonlinear mapping of an exponential function based on the variance ratio and short-range autocorrelation of the sequence, so as to amplify weak non-
quantum memory effects; obtaining an evaluation model containing a hyperbolic cosine and a logarithmic function by combining the drift potential of a bias
voltage relative to a target value and the aging time of a device, so as to obtain a dynamic entropy loss index; and comparing the entropy loss index with a preset threshold value, and performing
adaptive bias current feedback adjustment or triggering hardware fusing according to the comparison result. The present application solves the problem of implicit degradation of an entropy source caused by drift of a
detector operating point, and realizes precise closed-
loop control of the quality of the entropy source.