Ultra-Compact and Robust Physically Unclonable Function Based on Voltage-Compensated Proportional-to-Absolute-Temperature Voltage Generators

摘要

This paper presents a technique for designing an ultra-compact and robust physically unclonable function for security-oriented applications. The circuits are based on pairs of analog circuits whose output voltage is supply voltage compensated and proportional to absolute temperature (PTAT). The difference between two outputs of a PTAT pair is digitized to produce 1 b output which is sensitive mostly only to random transistor threshold voltage variations. Fabricated in a 65 nm, the proposed 256 b PUF array takes an area of 3.07 μm2/bit, consumes 0.548 pJ/bit at a throughput of 10 Mb/s, while showing desirable robustness against temperature and supply voltage variations with 3.5% and 1.004% bit-instability across 0 to 80°C and 0.6 to 1.2 V, respectively. The unpredictability and uniqueness of the 256 b PUF output are verified by NIST randomness test and Hamming Distance between keys. As compared with the state of the art, the proposed design has an 8.3× smaller area/bit or 2× better robustness against noise and environmental variations.