Hardware security: Threat models and metrics

The globalized semiconductor supply chain is vulnerable to hardware attacks including: Trojans, piracy of intellectual properties (IPs) and/or overbuilding of integrated circuits (ICs), reverse engineering, side-channels, and counterfeiting. In this paper, we explain the threat models, the state-of-the-art defenses, and the metrics used to evaluate the defenses. The threat models outlined in this paper enables one to understand the attacks. Defenses and metrics can help defenders to build stronger countermeasures and evaluate them against other protection techniques using the metrics.