Abstract: A method of generating a sequence of random bits is disclosed. The method comprises steps of (a) generating a stream of photons using a laser; (b) attenuating said series of photons; (c) reflecting at least a part of said stream of photons from a reflector positioned such that at least part of said stream of photons is directed from said reflector into the cavity of said laser; (d) directing a part of said stream of photons to a detector such that a signal proportional to the intensity of the radiation falling on said detector is produced; (e) sampling the AC component of said signal at a plurality of times, thereby obtaining a sampled signal comprising a sequence of data points; (f) obtaining the nth time derivative of said sampled signal over at least a portion of said sample signal; and (g) adding the m least significant bits (LSBs) of said nth time derivative to said sequence. By this method, truly random sequences of bits can be obtained at rates of up to at least 300 GBits/s.