A Low-Power Hybrid RO PUF With Improved Thermal Stability for Lightweight Applications

• Main Authors: Cao, Yuan, Zhang, Le, Chang, Chip-Hong, Chen, Shoushun
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2015
• Subjects: Hardware security; Physical unclonable function (PUF); Process variation; Ring oscillator (RO); Temperature stability
• Online Access: https://hdl.handle.net/10356/81334; http://hdl.handle.net/10220/39237
• Institution: Nanyang Technological University

Ring oscillator (RO) based physical unclonable function (PUF) is resilient against noise impacts, but its response is susceptible to temperature variations. This paper presents a low-power and small footprint hybrid RO PUF with a very high temperature stability, which makes it an ideal candidate for lightweight applications. The negative temperature coefficient of the low-power subthreshold operation of current starved inverters is exploited to mitigate the variations of differential RO frequencies with temperature. The new architecture uses conspicuously simplified circuitries to generate and compare a large number of pairs of RO frequencies. The proposed 9- stage hybrid RO PUF was fabricated using GF 65 nm CMOS technology. The PUF occupies only 250 m2 of chip area and consumes only 32.3 W per CRP at 1.2 V and 230 MHz. The measured average and worst-case reliability of its responses are 99.84% and 97.28%, respectively over a wide range of temperature from 40 to 120 ◦C.