A Random Number Generator includes a photon source, one or more photon detectors configured to detect at least one photon belonging to a flow of detected photons (λ) generated by the photon source, an electronic sampler operatively associated with the photon detectors and configured to implement a logic method for the extraction of a binary sequence based on the arrival time of each one of the detected photons (λ). In the Random Number Generator, the photon source and the photon detectors are adjacent to one another and integrated in a single semiconductor substrate.