Hybrid modeling attacks on current-based PUFs

Physically Unclonable Functions have emerged as a possible candidate to replace traditional cryptography. However, majority of the strong PUFs are vulnerable to modeling attacks. In this work, we take a closer look at the possible attacks on one of the strong PUF architectures known as Current-based PUFs, which exploit irregularities in transistor currents to generate unique signatures. We demonstrate that the fault-injection attacks when coupled with a machine learning (ML) algorithm can considerably push the limits of prediction accuracies. Based on simulations, we observed that the stand-alone ML algorithms suffer from error prone CRPs especially for higher length PUFs. In such scenarios, hybrid attacks exploiting the unreliable responses pushed the prediction accuracies up to 99% for higher length Current-based PUF circuits.