Physically Unclonable Functions Based on Single-Walled Carbon Nanotubes: A Scalable and Inexpensive Method toward Unique Identifiers

A physically unclonable function (PUF) is a physical system that cannot be reproduced or predicted and therefore is a good basis on which to build security and anticounterfeiting applications. The unclonability of PUFs typically stems from the randomness induced in a system during sophisticated fabrication methods. It is precisely this built-in complexity that is the bottleneck hindering scalability and increasing costs. Here, we produce in a simple manner PUFs based on arrays of carbon nanotube junctions simultaneously assembled by dielectrophoresis. We demonstrate that the intrinsic inhomogeneity of carbon nanotubes at the nanoscale, combined with the unpredictability introduced by liquid phase-based fabrication methods, results in unique electronic profiles of easily scalable devices. This approach could be extrapolated to generate PUFs and thus advanced identification systems based on other nanoscale materials.