Exploiting Multi-Phase On-Chip Voltage Regulators as Strong PUF Primitives for Securing IoT

The physical randomness of the flying capacitors in the multi-phase on-chip switched-capacitor (SC) voltage converter is exploited as a novel strong physical unclonable function (PUF) primitive for IoT authentication. Moreover, for the strong PUF we devised, an approximated constant input power is achieved against side-channel attacks and a non-linear transformation block is utilized to scramble the high linear relationship between the input challenges and output responses against machine-learning attacks. The results show that the novel strong PUF primitive we designed achieves a nearly 51.3% inter-Hamming distance (HD) and 98.5% reliability while maintaining a high security level against both side-channel and machine-learning attacks.