Random code for device identification

A method for distinguishing transmissions of a wireless transmitter, the method comprising:

• generating a random identifier code having randomness that is derived from manufacturing tolerances associated with components included in the wireless transmitter, the generation of the random identifier code being configured to repeatedly obtain a same result;
• and
• embedding the random identifier code in the transmissions of the wireless transmitter,
• wherein the wireless transmitter includes a microcontroller unit having an input/output (I/O) port, and the generating step is in response to an event responsive to the manufacturing tolerances being detected at the I/O port.

A method for distinguishing transmissions of a transceiver included in a wireless communications system, the method comprising:

• generating a random identifier code having randomness that is derived from manufacturing tolerances associated with components included in the transceiver;
• and
• embedding the random identifier code in the transmissions of the transceiver, the generation of the random identifier code being configured to repeatedly obtain a same result,
• wherein the wireless transmitter includes a microcontroller unit having an input/output (I/O) port, and the generating step is in response to an event responsive to the manufacturing tolerances being detected at the I/O port.

A computer-readable medium having instructions stored thereon which, when executed by a processor included in a wireless communications system, when executed by a processor included in a wireless communications system, cause the processor to perform the steps of:

• in response to an event responsive to manufacturing tolerances associated with components included in the communications system, receiving data produced by the wireless communications system, wherein the received data has randomness that is derived from the manufacturing tolerances associated with the components included in the wireless communications system;
• generating a random identifier code based on the received data;
• and
• storing the random identifier code in a storage area included in the wireless communications system, the generation of the random identifier code being configured to repeatedly obtain a same result.

A method for distinguishing transmissions of a wireless communications device, wherein the wireless communications device has a microcontroller unit having an input/output (I/O) port coupled to a resistor capacitive (RC) circuit having an output voltage that can be monitored by the I/O port, the method comprising:

• responsive to a triggering event, commanding the I/O port of the microcontroller unit from a high impedance state to a low voltage state thereby discharging the RC circuit;
• resetting and starting an N-bit timer of the microcontroller unit, the N-bit timer having an output;
• commanding the I/O port from the low voltage state to the high impedance state thereby charging the RC circuit;
• monitoring the output voltage of the RC circuit at the I/O port;
• responsive to the output voltage at the I/O port reaching a threshold voltage, reading the output of the N-bit timer;
• generating from the read output of the N-bit timer a random identifier code;
• and
• embedding the random identifier code in transmissions of the wireless communications device.