A printed circuit board (PCB), an indispensable part of modern electronics, mechanically supports and electrically connects electronic components using conductive tracks, pads and other features etched from copper sheets laminated onto a non-conductive substrate. PCBs can be single sided (one copper layer), double sided (two copper layers) or multi-layer.
PCBs may be populated with components, such as capacitors, resistors or active devices (e.g., integrated circuit chips) attached to or embedded in the substrate. Growing reliance on untrusted design and fabrication houses makes modern PCBs vulnerable to diverse security issues during manufacturing. Moreover, the increasingly complex global semiconductor supply chain, spanning different countries and their legal systems to meet the ever-rising demand, provides ample opportunities for adversaries to insert counterfeit PCBs in the market. Purchasers rely on brokers, who in turn may buy from untrustworthy entities including online forums. Finally, a PCB can be tampered during field operation through physical access. Such tampering can allow an adversary to gain unauthorized access to components in a PCB; snoop in secret data being transmitted through buses; or add undesired functionality to it.
With growing incidences of PCB integrity violations at different level, there is a critical need to achieve high level of trust and assurance in PCBs used in diverse electronic devices, including mission-critical systems. We have developed an array of tools and techniques to provide low-cost solutions for validating PCB integrity in presence of diverse attacks in untrusted design house / foundry, in the supply chain, or during deployment.