An electronic system and corresponding method for authenticating firmware stored in a memory element external to a processor. In one embodiment, an electronic system comprises a processor and a memory element. The memory element is used to contain firmware and a digital signature of the firmware signed by a signatory. Coupled to the memory element, the processor authenticates the firmware during a predetermined condition, which occurs prior to execution of the firmware, through use of a pre-stored public key of the signatory and a pre-stored digital signature function.