Biblio
This paper introduces a new methodology to generate additional hardware security in commercial off-the-shelf (COTS) system-on-a-chip (SoC) integrated circuits (ICs) that have already been fabricated and packaged. On-chip analog hardware blocks such as analog to digital converters (ADCs), digital to analog converters (DACs) and comparators residing within an SoC are repurposed and connected to one another to generate unique physically unclonable function (PUF) responses. The PUF responses are digitized and processed on-chip to create keys for use in encryption and device authentication activities. Key generation and processing algorithms are presented that minimize the effects of voltage and temperature fluctuations to maximize the repeatability of a key within a device. Experimental results utilizing multiple on-chip analog blocks inside a common COTS microcontroller show reliable key generation with minimal overhead.
The use of side-channel measurements and fingerprinting, in conjunction with statistical analysis, has proven to be the most effective method for accurately detecting hardware Trojans in fabricated integrated circuits. However, these post-fabrication trust evaluation methods overlook the capabilities of advanced design skills that attackers can use in designing sophisticated Trojans. To this end, we have designed a Trojan using power-gating techniques and demonstrate that it can be masked from advanced side-channel fingerprinting detection while dormant. We then propose a real-time trust evaluation framework that continuously monitors the on-board global power consumption to monitor chip trustworthiness. The measurements obtained corroborate our frameworks effectiveness for detecting Trojans. Finally, the results presented are experimentally verified by performing measurements on fabricated Trojan-free and Trojan-infected variants of a reconfigurable linear feedback shift register (LFSR) array.