Defeating hardware Trojan in microprocessor cores through software obfuscation

In recent years a new kind of threat, known as Hardware Trojan, is affecting the Integrated Circuit industry. Un-trusted parties in the supply chain may take advantage of the segmentation in the production to inject malicious hardware components that became active under specific circumstances. As it is impractical to identify such malicious hardware with in-lab testing, most countermeasures are based on hardware alterations, with the drawback of increasing production costs, area, and energy consumption of the final product. In this paper, on the contrary, we propose a software-based, cost-effective solution that minimizes the chance of activation of a multi-stage trigger Hardware Trojan. The approach relies on a pure-software obfuscation mechanism, which exploits an evolutionary algorithm to modify an executable program without affecting its functionalities. Such obfuscation can be used to protect critical infrastructures and operations with a reduced and predictable loss of performances. The proposed technique has been evaluated against a well-known real-world hardware attack, getting positive and promising results concerning its effectiveness.