A power supply unit (PSU) comprises power conversion circuitry to convert input power into output power for an electronic system, microcontrollers to control operations of the power conversion circuitry, and a secure element communicably connected to a first microcontroller. The secure element and the microcontrollers are all paired together with each storing shared pairing information. The secure element and the microcontrollers comprise security logic. The security logic may be configured to, in response to a power on sequence being initiated, validate the secure element and the microcontrollers based on the shared pairing information, and make completion of the power on sequence conditional on successful validation. The security logic may be configured to, in response to receiving a new firmware image for updating one of the microcontrollers, use the secure element to validate the new firmware image and make acceptance of the new firmware image conditional on successful validation.