System and methods for silencing hardware backdoors

摘要

Methods for preventing activation of hardware backdoors installed in a digital circuit, the digital circuit comprising one or more hardware units to be protected. A timer is repeatedly initiated for a period less than a validation epoch, and the hardware units are reset upon expiration of the timer to prevent activation of a time-based backdoor. Data being sent to the hardware unit is encrypted in an encryption element to render it unrecognizable to a single-shot cheat code hardware backdoor present in the hardware unit. The instructions being sent to the hardware unit are reordered randomly or pseudo-randomly, with determined sequential restraints, using an reordering element, to render an activation instruction sequence embedded in the instructions unrecognizable to a sequence cheat code hardware backdoor present in the hardware unit.

主权项

1. A method for preventing activation of hardware backdoors installed in a digital circuit, the digital circuit comprising one or more hardware units to be protected and a clock which produces a clock signal, the method comprising:
initiating a timer set for a period less than or equal to a determined validation time period of the digital circuit; performing a reset operation on the hardware units upon expiration of the timer by turning off power to the hardware units for at least one cycle of the clock signal to interrupt operation of the hardware units; continually repeating the initiating of the timer for further reset operations while the digital circuit is in operation.