Security for power supply unit microcontrollers

A method comprising:

• providing a power supply unit (PSU) comprising a first microcontroller, a second microcontroller, and a secure element paired together with each storing a copy of a pairing key;
• in response to a power on sequence of the PSU being initiated:
• using the first microcontroller to validate the identity of the secure element based at least in part on the first microcontroller's copy of the pairing key;
• using the second microcontroller to validate the identity of the first microcontroller based at least in part on the second microcontroller's copy of the pairing key;
• and
• using the first microcontroller to validate the identity of the second microcontroller at least in part on the first microcontroller's copy of the pairing key;
• and
• making completion of the power on sequence conditional upon successful validation of each of the secure element, the first microcontroller, and the second microcontroller.

A method comprising:

• providing a power supply unit (PSU) comprising a first microcontroller, a second microcontroller, and a secure element;
• programming the first and second microcontrollers and the secure element;
• pairing the first and second microcontrollers and the secure element by:
• causing the secure element to generate a pairing key,
• sharing copies of the pairing key with the first and second microcontrollers, and
• increasing the security of the secure element such that the security element accepts commands only if accompanied by valid message authentication codes validated by the secure element based on the pairing key.