Volume 22 (2014) Issue 2 Pages 344-356
In this study, the properties of physical unclonable functions (PUFs) for 28-nm process field-programmable gate arrays (FPGAs) are examined. A PUF is a circuit that generates device-specific IDs by extracting device variations. Owing to device variation, no two PUFs will generate the same ID even if they have identical structures and are manufactured on the same silicon wafer. However, because the influence of device variation increases as the size of the process node shrinks, it is uncertain whether PUFs can be built using recently developed small-scale process nodes, even though the technology of variation control is constantly advancing. While many PUFs using 40-nm or larger process nodes have been reported, smaller devices have not yet been studied to the authors' knowledge, and this is the first published journal article on PUFs for 28-nm process FPGAs. In this paper, within-die reproducibility, die-to-die uniqueness, and other properties are evaluated, and the feasibility of PUFs on 28-nm FPGAs is discussed.