Ultra-energy-efficient temperature-stable physical unclonable function in 65 nm CMOS

Physical unclonable functions (PUFs) are promising hardware security primitives suitable for resource-constrained devices requiring lightweight cryptographic methods. This Letter proposes an ultra-low-power and reliable PUF based on a customised dynamic two-stage comparator operating in the sub-threshold region. The proposed PUF is implemented in a standard 65 nm CMOS technology and validated through Monte-Carlo simulations. Evaluation results show a worst-case reliability of 98.3% over the commercial temperature range of 0°C to 85°C and 10% fluctuations in supply voltage. In addition, the 128-bit PUF array consumes only 1.33 μW at 1 Mb/s, which corresponds to 10.3 fJ/bit, being the most energy-efficient design to date.