A novel configurable ring oscillator PUF with improved reliability using reduced supply voltage

Out of several delay based Physical Unclonable Functions (PUF), Configurable Ring oscillator (CRO) PUF is a preferred security primitive because of its higher reliability, area efficient CRO section and low power consumption features. The reliability degradation occurs mainly due to temperature variation and aging. Although conventional CRO PUF is highly reliable against temperature variation but it shows less resilient to aging. In this paper, we propose two modified CRO PUF architectures for better reliability against aging related issues. The first architecture uses reduced supply voltage approach to minimize the reliability degradation due to both temperature variation and aging. The second architecture uses a response dependent supply voltage controller approach to prevent reliability degradation by restoring the initial logic level of responses. Both the proposed modified CRO PUF architectures are power efficient than the conventional CRO PUF. Further, the use of single row of cascaded inverter as CRO made both the proposed architectures area efficient than conventional CRO PUF. The performance analysis is carried out in 90 nm CMOS technology. Simulation result confirms improvements in reliability along with low power feature for both the proposed modified CRO PUF.