Interacting with Hardware Trojans over a network

Hardware Trojan horses (HTHs) are emerging threats to integrated circuits (ICs) outsourced to a global supply chain or developed with untrusted tools and intellectual property (IP). HTHs are stealthy in nature, and covert communication is their usual means of interaction and information transfer. Previous research has focused on short-range interaction via side-channels and existing IC interfaces, while remote interaction with HTHs across wired computer networks has received less attention. Generalized and non-local HTH interaction can support attacks normally associated with software Trojans. We investigate remote communication with HTHs and provide partial methods to exploit vulnerabilities in media layers of the protocol stack. Specifically, we focus on covert communication over point-to-point physical links in 10 gigabit Ethernet (10GbE) networks by exploiting loose specifications in physical- and link-layer protocols. The developed HTHs are assessed in terms of resource overhead and achieved bit rate, and demonstrate the potential for establishing high bandwidth covert channels using lightweight implanted circuits. We also describe a PUF-based IC or IP tracking attack enabled by HTH interaction across a network.