The invention relates to a device for generating random numbers, comprising a pair of memristors. The pair of memristors comprises a first and a second memristor, each memristor of the pair in turn comprises a top electrode, a bottom electrode and an intermediate layer adapted to switch resistance in response to predetermined voltage values applied between the top electrode and the bottom electrode. Each memristor is operatively connected to an output terminal by means of its bottom electrode. A control logic is connected to the memristors for applying suitable voltages necessary to determine a change of resistance in at least one memristor of the pair.