International Association
for Cryptologic Research

Physically Unclonable Functions (PUFs) exploit the physical characteristics of silicon and provide an alternative to storing digital encryption keys in non-volatile memory. A PUF maps a unique set of digital inputs to a corresponding set of digital outputs. In this paper, the use of asynchronous logic and design techniques to implement PUFs is advocated for Asynchronous Physically Unclonable Functions (APUFs). A new method of using asynchronous rings to implement PUFs is described called ASYNCPUF which features inherent field programmability. It is both a novel and holistic PUF design compared to the existing state-of-the-art as it naturally addresses the two challenges facing PUFs to-date that prevent wide-spread adoption: robustness and entropy. Results of electrical simulation in a 90 nano-meter lithography process are presented and discussed.