Physically Unclonable Functions: Design Principles, Applications and Outstanding Challenges

Physically Unclonable Functions (PUF) are a class of hardware security primitives, constructed to exploit the intrinsic variations in the integrated circuit fabrication process to give each silicon chip a unique identifier, in other words, a hardware-based fingerprint. Their relatively simple architectures and small overheads can answer many of the security challenges facing computing devices especially those operating in energy-constrained and/or physically exposed environments. The first part of this talk provides a comprehensive overview on the design principles of physically unclonable functions and their main evaluation metrics. The second part explains why we need the PUF technology and how to use it to build robust defence mechanisms against emerging security threats, giving specific examples that includes secure cryptographic keys generation/storage, authentication protocols, anti-counterfeit design for integrated circuits (IC) and low-cost secure sensors. The final part outlines the outstanding security challenges facing PUF technology and their potential countermeasures, including mathematical modelling attacks using machine-learning algorithms, side channel attacks and physical cloning attacks. The talk concludes with a summary of learned lessons and directions for the future.