1. ELECTRONIC DEVICE FOR CODING AND DECODING ELECTRIC SIGNALS TO MULTIPLY A CLEAR SIGNAL WITH A RANDOM SIGNAL, THE SIGN OF THE PRODUCT BEING GIVEN BY THE RULE OF THE MULTIPLICATION OF THE SIGNS, COMPRISING TWO SATURABLE MAGNETIC CORES ARRANGED IN THE FORM OF A MAGNETIC AMPLIFIER, EACH CORE BEING PROVIDED WITH A PLURALITY OF WINDINGS WOUND THEREON INCLUDING AT LEAST ONE POWER WINDING FED BY A SEPARATE SOURCE OF ALTERNATING CURRENT, TWO CONTROL WINDINGS AND A BIAS WINDING, AND TWO CIRCUIT BRANCHES, EACH OF WHICH COMPRISES ONE OF THE POWER WINDINGS IN SERIES WITH A RECTIFIER, THE TWO CIRCUIT BRANCHES BEING EFFECTIVELY CONNECTED IN PARALLEL WITH RESPECT TO A TRANSISTOR, THE POWER WINDINGS BEING CONNECTED IN OPPOSITION IN SUCH MANNER THAT THE TWO CORES NOT SIMULTANEOUSLY SATURATED, ONE OF THE TWO CONTROL WINDINGS OF ONE OF THE MAGNETIC CORES BEING CONNECTED IN SERIES WITH ANOTHER CORE OF THE CONTROL WINDINGS OF THE OTHER MAGNETIC CORE IN TWO GROUPS, TO WHCH THE TWO SIGNALS TO BE MAGNETIC CORE IN TWO GROUPS, TO WHICH THE TWO SIGNALS TO BE MULTIPLIED ARE RESPECTIVELY APPLIED, AND THE RESULTANT SIGNAL OF THE MULTIPLICATION OF THE SIGNALS BEING PRESENT AT THE OUTPUT OF THE TRANSISTOR.