Food-Grade Physically Unclonable Functions

Abstract

Counterfeit products in the pharmaceutical and food industries have posed an overwhelmingly increasing threat to the health of individuals and societies. An effective approach to prevent counterfeiting is the attachment of security labels directly on drugs and food products. This approach requires the development of security labels composed of safely digestible materials. In this study, we present the fabrication of security labels entirely based on the use of food-grade materials. The key idea proposed in this study is the exploitation of food-grade corn starch (CS) as an encoding material based on the microscopic dimensions, particulate structure, and adsorbent characteristics. The strong adsorption of a food colorant, erythrosine B (ErB), onto CS results in fluorescent CS@ErB microparticles. Randomly positioned CS@ErB particles can be obtained simply by spin-coating from aqueous solutions of tuned concentrations followed by transfer to an edible gelatin film. The optical and fluorescence microscopy images of randomly positioned particles are then used to construct keys for a physically unclonable function (PUF)-based security label. The performance of PUFs evaluated by uniformity, uniqueness, and randomness analysis demonstrates the strong promise of this platform. The biocompatibility of the fabricated PUFs is confirmed with assays using murine fibroblast cells. The extremely low-cost and sustainable security primitives fabricated from off-the-shelf food materials offer new routes in the fight against counterfeiting.

Ultradurable Embedded Physically Unclonable Functions

“…Motivated by the accelerating needs of encoded surfaces in anticounterfeiting and authentication, a diverse range of processes and materials have been recently explored for generation of PUFs. Quantum dots, − perovskite nanocrystals, luminescent materials, , plasmonic nanoparticles, − 2D materials, organic semiconductors, graphene, food-grade starch, self-wrinkling materials, , self-assembly of polymers, light-emitting organic molecules, electronic fingerprints, laser-induced carbonization, and polymeric particles are good examples to recent reports. The rich menu of materials proposed for PUF applications provides viable options for the vastly diverse needs of these applications.…”

Electrospray deposition of physical unclonable functions for drug anti-counterfeiting

“…Here, we deploy optical PUFs 32 that are visible to the naked eye and can be imaged with a standard cellphone camera. This is in contrast to micro- or nano-scale PUFs that require electron/optical microscopy or other specialized tools for imaging and authentication 13 , 17 , 20 , 33 . Optical ePUFs are appealing for consumers that are unlikely to have access to the specialized tools that would be required for micro-/nano- PUFs.…”