Magnetic steganography based on wide field diamond quantum microscopy

TL;DR

This paper demonstrates magnetic steganography using wide field diamond quantum microscopy with nitrogen vacancy centers, enabling concealed magnetic image detection and improved imaging speed, with potential applications in secure information hiding.

Contribution

It introduces a novel magnetic steganography technique using diamond quantum microscopy and compares imaging modes for optimal concealed image reconstruction.

Findings

Contrast-based imaging mode yields best hidden image quality.

Simultaneous microwave driving triples imaging speed.

Magnetic steganography demonstrated with pixel art, barcodes, QR codes.

Abstract

We experimentally demonstrate magnetic steganography using wide field quantum microscopy based on diamond nitrogen vacancy centers. The method offers magnetic imaging capable of revealing concealed information otherwise invisible with conventional optical measurements. For a proof of principle demonstration of the magnetic steganography, micrometer structures designed as pixel arts, barcodes, and QR codes are fabricated using mixtures of magnetic and nonmagnetic materials, nickel and gold. We compare three different imaging modes based on the changes in frequency, linewidth, and contrast of the NV electron spin resonance, and find that the last mode offers the best quality of reconstructing hidden magnetic images. By simultaneous driving of the NV qutrit states with two independent microwave fields, we expediate the imaging time by a factor of three. This work shows potential applications of quantum magnetic imaging in the field of image steganography.