Self-assembled physical unclonable function labels based on plasmonic coupling

TL;DR

This paper introduces nanoscale plasmonic PUF labels created through self-assembly techniques, offering secure, hard-to-replicate optical identifiers that are cost-effective and suitable for anti-counterfeiting applications.

Contribution

The work demonstrates a novel method for fabricating optical PUFs using self-assembled plasmonic nanoparticles with nanoscale variations, enhancing security and read-out simplicity.

Findings

Nanoscale variations define unique optical scattering colors.

PUFs are virtually impossible to replicate due to nanoscale randomness.

Read-out can be performed with economical 3D-printed hardware.

Abstract

Counterfeiting threatens human health, social equity, national security and global and local economies. Hardware-based cryptography that exploits physical unclonable functions (PUFs) provides the means for secure identification and authentication of products. While optical PUFs are among the hardest to replicate, they suffer from low encoding capacity and often complex and expensive read-out. Here we report PUF labels with nanoscale features and optical responses that arise from the guided self-assembly of plasmonic nanoparticles. Nanosphere lithography combined with DNA origami placement are used to create tightly packed randomised nanoparticle assemblies. Nanoscale variations within these assemblies define the scattering color of the individual spots that are arranged in a hexagonal lattice with spacing down to the optical resolution limit. Due to the nanoscale dimensions, the intrinsic randomness of the particle assemblies and their resulting optical responses, our PUFs are virtually impossible to replicate while they can be read-out with economical 3D-printed hardware.