Unique signatures from printed circuit board design patterns and surface mount passives

Counterfeiting or surreptitious modification of electronic systems is of increasing concern, particularly for critical infrastructure and national security systems. Such systems include avionics, medical devices, military systems, and utility infrastructure. We present experimental results from an approach to uniquely identify printed circuit boards (PCBs) on the basis of device unique variations in surface mount passive components and wire trace patterns. We also present an innovative approach for combining measurements of each of these quantities to create unique, random identifiers for each PCB and report the observed entropy, reliability, and uniqueness of the signatures. These unique signatures can be used directly for verifying the integrity and authenticity of the PCBs, or can serve as the basis for generating cryptographic keys for more secure authentication of the devices during system acquisition or field deployment. Our results indicate that the proposed approaches for measuring and combining these quantities are capable of generating high-entropy, unique signatures for PCBs. The techniques explored do not require system designers to utilize specialized manufacturing processes and implementation is low-cost.