The invention describes a device (1) comprising: a first circuit (2) generating transient pulses having an input (2e) and an output (2s); a second circuit (3) transient pulse generator, identical to the first except for the inherent differences in the manufacturing process, which has an input (3e) and an output (3s); a circuit (4) referee that has first and second entries (4e1, 4e2) connected to the exit (2s) and to the exit (3s), and an exit (4s) of referee circuit, where the circuit (4) referee is configured to determine if an input signal "question" entered simultaneously in the input (2e) and in the input (3e) arrives before as a pulse to the output (2s) or to the output (3s) and to emit an output pulse depending on it through the exit (4s) of the referee circuit. (Machine-translation by Google Translate, not legally binding)