Assessing Temperature Sensitivity and Ring Oscillator Count Impact on Configurable Ring Oscillator PUF Performance

Physically Unclonable Functions (PUFs) have been introduced as highly promising hardware primitives for key-based security applications. A PUF can be thought of as a hardware fingerprint that is able to produce a device-specific key for utilization in applications involving device identification and cryptographic key-based security. Among various PUF approaches, the ring oscillator (RO) PUF stands out as the most common PUF design due to its simple implementation and high-performance features. However, RO-PUFs are often classified as weak PUFs due to their limited input-output combinations, commonly referred to as challenge-response pairs within the scope of PUFs. Increasing the CRPs size of traditional RO-PUF results in a proportional growth in the hardware requirements for the RO-PUF design. This correlation arises from the linear relationship between the CRPs size and the hardware resources necessary for the RO-PUF design. Configurable RO-PUF emerged as a solution that expands the CRPs size without a substantial hardware increase. This study evaluates the performance reliability of CRO-PUF across various temperatures. Additionally, we explore the impact of altering the ring oscillators count on the CRO-PUF's performance.