BACKGROUND

Security of hardware and software is paramount as computing devices (e.g., laptop, tablet, smart phone, computers, servers, internet-of-things, etc.) become the daily fabric of users. Signals on the physical pins of processor can be manipulated to cause the processor to perform an unintended function. For example, data stored in a non-volatile memory for internal use of the processor may be retrieved by unauthorized users using different signals on the pins of the processor. Likewise, software executing on the processor may cause the hardware of the processor to perform unauthorized functions (e.g., lowering the divider ratio of a phase locked loop). While many efforts have been made to mitigate and/or remove software viruses from computing devices, hardware largely remains unprotected for a sophisticated hacker.

