Malicious alterations of Integrated Circuits (ICs), introduced during either the design or fabrication process, are increasingly perceived as a serious concern by the global semiconductor industry. Such rogue alterations often take the form of a \"Hardware Trojan\", which may be activated from remote after the compromised chip or system has been deployed in the field. The devious actions of hardware Trojans can range from the disabling of all or part of the chip (i.e. \"Kill switch\"), over the activation of a backdoor that allows an adversary to gain access to the system, to the covert transmission of sensitive information (e.g. cryptographic keys) off-chip.