Certificate-based pairing of key fob device and control unit

A control unit comprising:

• a transceiver;
• a memory to store instructions;
• and
• a processor coupled to the transceiver and memory, wherein the processor is configured to execute the instructions to cause the control unit to:
• receive a first transmission containing a certificate;
• verify the authenticity of the certificate;
• after verifying authenticity of the certificate, establish a first communication link using transceiver to execute a public key agreement protocol to generate a first common secret encryption key;
• receive a second transmission containing an encrypted first public key, wherein the encrypted first public key is encrypted by the first common secret encryption key;
• decrypt the encrypted first public key using the first common secret encryption key to determine the first public key;
• after determining the first public key, establish a second communication link using the transceiver to execute a public key agreement protocol to generate a second common secret encryption key;
• generate an operational key;
• encrypt the operational key using the second common secret encryption key;
• and
• transmit the encrypted operational key.