Abstract: Quantum Random Number Generator comprising an emitting device (1) adapted to be triggered by a signal representing an input bit x and adapted to generate and send a stream of one of two possible non-orthogonal quantum states determined by a plurality of said input bit x at a rate in the range of Mb/s up to 10 Gb/s, a measurement device (2) adapted to detect each quantum state of the stream of quantum states sent by the emitting device (1) and to generate an output b based on the detected quantum state, a random selection device (3) adapted to receive said output b and carries out a random selection on said output b so as to select and pick out a first fraction of the bits b? and a second fraction of the bit b-b? sent to an entropy (I) estimation module (4, 4?), wherein the entropy (I) estimation module (4, 4?) is adapted to receive the input x, the output b? and the output b-b? over a certain number of rounds N and to estimate the entropy (I) of each output for each quantum state of the stream of quantum stat