Secure and Energy Efficient Physical Unclonable Functions

Physical Unclonable Functions are a unique class of circuits that leverage the inherentvariations in manufacturing process to create unique,unclonableIDs and secret keys.The distinguishing feature of PUFs is that even an untrusted foundry cannot create a copy of the circuit as it is impossible to control the manufacturing process variations.PUFs can operate reliably in presence of voltage and temperature variations. In thisthesis, weexplorethe security offered by PUFs and tradeoffs between different metrics such as uniqueness, reliability and energy consumption.Benefits of sub-threshold PUF operation and the use of delay based Arbiter PUFs and ring oscillator PUFs in low power applications is evaluated. As we scale into lower technology nodes, there exists sufficient inter chip variation that enables each IC to be identified securely.The impact of scaling on the identification capabilities of a PUF and its reliability has been demonstrated in this work by analyzing the behavior of an Arbiter PUF in 45nm, 32nm and 22nm technology nodes. Further,the Arbiter PUF design has been implemented on a test-chip and fabricated using 45nm industry models andresults from post silicon validation are presented. Finally, we investigate a new class of PUF circuits in this work, that provide better security against machine learning based software modeling attacks. The strong identification capabilities and sufficiently high reliability offered by these PUF circuits make them promising candidates for future applications requiring securehardware cryptographic primitives

Implementing hardware Trojans: Experiences from a hardware Trojan challenge

Abstract—Hardware Trojans have become a growing concern in the design of secure integrated circuits. In this work, we present a set of novel hardware Trojans aimed at evading detection methods, designed as part of the CSAW Embedded System Challenge 2010. We introduced and implemented unique Trojans based on side-channel analysis that leak the secret key in the reference encryption algorithm. These side-channel-based Trojans do not impact the functionality of the design to minimize the possibility of detection. We have demonstrated the statistical analysis approach to attack such Trojans. Besides, we introduced Trojans that modify either the functional behavior or the electrical characteristics of the reference design. Novel techniques such as a Trojan draining the battery of a device do not have an immediate impact and hence avoid detection, but affect the long term reliability of the system. Keywords- Hardware Trojan, side-channel, hardware security I

INTENTIONAL AND UNINTENTIONAL SIDE-CHANNELS IN EMBEDDED SYSTEMS

I would also like to thank CRI for a great internship as well as the students of my Security Engineering class for their patience with me (I really hope you enjoyed the class as I did). Last not least I want to thank my siblings, my “old friends ” in Germany, as well as my “new friends ” in the US for helping me keeping sane. Due to you guys, the last four years were actually quite fun: