Optical nano artifact metrics using silicon random nanostructures

TL;DR

This paper introduces an optical method using confocal laser microscopy to characterize silicon nanostructures for secure authentication, offering a low-cost alternative to electron microscopy with high nanoscale precision.

Contribution

It demonstrates a novel optical approach for nano artifact metrics utilizing silicon random nanostructures, enabling secure, high-precision identification without expensive equipment.

Findings

Confocal laser microscopy achieves nanoscale height measurement precision.

Silicon nanostructures can be reliably cloned and distinguished.

Statistical analysis confirms security potential of the nanostructure signatures.

Abstract

Nano artifact metrics exploit unique physical attributes of nanostructured matter for authentication and clone resistance, which is vitally important in the age of Internet-of-Things where securing identities is critical. However, high-cost and huge experimental apparatuses, such as scanning electron microscopy, have been required in the former studies. Herein, we demonstrate an optical approach to characterise the nanoscale-precision signatures of silicon random structures towards realising low-cost and high-value information security technology. Unique and versatile silicon nanostructures are generated via resist collapse phenomena, which contains dimensions that are well below the diffraction limit of light. We exploit the nanoscale precision ability of confocal laser microscopy in the height dimension, and our experimental results demonstrate that the vertical precision of measurement is essential in satisfying the performances required for artifact metrics. Furthermore, by using state-of-the-art nanostructuring technology, we experimentally fabricate clones from the genuine devices. We demonstrate that the statistical properties of the genuine and clone devices are successfully exploited, showing that the liveness-detection-type approach, which is widely deployed in biometrics, is valid in artificially-constructed solid-state nanostructures. These findings pave the way for reasonable and yet sufficiently secure novel principles for information security based on silicon random nanostructures and optical technologies.