Degree Type


Date of Award


Degree Name

Doctor of Philosophy


Electrical and Computer Engineering


Computer Engineering

First Advisor

Randall Geiger


Hardware security and hardware authentication have become more and more important concerns in the manufacture of trusted integrated circuits. In this dissertation, a detailed study of hardware Trojans in analog circuits characterized by the presence of extra operating points or modes is presented. In a related study, a counterfeit countermeasure method based upon PUF authentication circuits is proposed for addressing the growing proliferation of counterfeit integrated circuits in the supply chain.

Most concerns about hardware Trojans in semiconductor devices are based upon an implicit assumption that attackers will focus on embedding Trojans in digital hardware by making malicious modifications to the Boolean operation of a circuit. In stark contrast, hardware Trojans can be easily embedded in some of the most basic analog circuits. In this work, a particularly insidious class of analog hardware Trojans that require no architectural modifications, no area or power overhead, and prior to triggering, that leave no signatures in any power domains or delay paths is introduced. The Power/Architecture/Area/Signature Transparent (PAAST) characteristics help the Trojan “hide” and make them very difficult to detect with existing hardware Trojan detection methods. Cleverly hidden PAAST Trojans are nearly impossible to detect with the best simulation and verification tools, even if a full and accurate disclosure of the circuit schematic and layout is available. Aside from the work of the author of this dissertation and her classmates, the literature is void of discussions of PAAST analog hardware Trojans. In this work, examples of circuits showing the existence of PAAST analog hardware Trojans are given, the PAAST characteristics of these types of hardware Trojans are discussed, and heuristic detection methods that can help to detect these analog hardware Trojans are proposed.

Another major and growing problem in the modern IC supply chain is the proliferation of counterfeit chips that are often characterized by different or inferior performance characteristics and reduced reliability when compared with authentic parts. A counterfeit countermeasure method is proposed that should lower the entry barrier for major suppliers of commercial off the shelf (COTS) parts to offer authenticated components to the military and other customers that have high component reliability requirements. The countermeasure is based upon a PUF authentication circuit that requires no area, pin, or power overhead, and causes no degradation of performance of existing and future COTS components.

Copyright Owner

Qianqian Wang



File Format


File Size

176 pages