Experimental Implementation of Metasurfaces for Secure Multi-Channel Image Encryption in the Infrared

Abstract

The ability to tailor light–matter interactions using artificially engineered materials has opened up new avenues for secure data storage and communication. This work presents an experimental investigation of metasurfaces for secure, multi-channel image encryption in the infrared (IR). The proposed metasurfaces consist of an array of pixels, each designed to produce a wavelength- and polarization-dependent IR absorptivity. A basis set of pixels is designed for encrypting images of arbitrary resolution on a given number of wavelength and polarization channels. These pixels are fabricated, and their spectral response is experimentally measured using Fourier transform infrared spectroscopy. The measured data is used to emulate the encryption and decryption of binary and 8-bit grayscale images. Finally, the security of the encryption scheme proposed in this work is evaluated by performing statistical analyses on the image data stored on different channels. The results presented in this study suggest intriguing possibilities for the development of encrypted tagging technologies in the infrared and thus have implications for secure object identification and anti-counterfeiting.