Thermal Attack on RO-PUFs: The Cases of Bulk 65 nm and FDSOI 28 nm

Physical Unclonable Functions (PUFs) play a crucial role in enhancing the security of electronic devices by leveraging inherent manufacturing variations to generate unique and unclonable identifiers. This study explores the vulnerability of Ring Oscillator-based PUFs (RO-PUFs) to thermal attacks, focusing on two semiconductor technologies: Bulk 65 nm and Fully Depleted Silicon on Insulator (FDSOI) in 28 nm. Through detailed simulations, the effects of uniform and localized thermal variations on the stability of ring oscillator frequencies are analyzed. The results reveal that while the Bulk 65 nm technology shows resistance to uniform thermal attacks, it is highly sensitive to localized attacks. In contrast, the FDSOI 28 nm technology is vulnerable to both types of attacks due to its low variability. These observations underscore the need for robust countermeasures in the design of PUFs to ensure their reliability under varying thermal conditions.