True random number generator

A random number generator of the type comprising:

• a photon source;
• one or more photon detectors of the SPAD type configured in such a way as to detect a flow of photons equal to λ, said photons being generated by said photon source;
• electronic sampling means configured in such a way as to detect the arrival time t of a photon incident on each one of said SPAD photon detectors for each one of said observation windows with duration Tw, said electronic sampling means being furthermore configured in such a way as to convert said arrival time t into a binary sequence with length equal to n=log2 r, r being the number of time portions having the same duration into which each one of said observation windows with duration Tw is subdivided, said binary sequence assuming a value that depends on the specific time portion within which said arrival time t falls,
• wherein the photon source and said electronic sampling means are configured in such a way that the product λ*Tw between the detected photon flow λ and the duration Tw of each observation window is less than or equal to 0.01.