Hiding images in noise

Johnson, Steven and McMillan, Alex and Frick, Stefan and Rarity, John and Padgett, Miles (2023) Hiding images in noise. Optics Express, 31 (4). pp. 5290-5296. ISSN 1094-4087 (https://doi.org/10.1364/OE.480881)

[thumbnail of Johnson-etal-OE-2024-Hiding-images-in-noise]
Preview
 Text. Filename: Johnson-etal-OE-2024-Hiding-images-in-noise.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo
Download (3MB)| Preview

Abstract

A limitation of free-space optical communications is the ease with which the information can be intercepted. This limitation can be overcome by hiding the information within background optical noise. We demonstrate the transfer of images over free-space using a photon-pair source emitting two correlated beams. One of these beams contains image information, to which noise is added, and the other correlated beam is used as a heralding trigger so that the intended recipient can differentiate this image signal from the background noise. The system uses spontaneous parametric down-conversion to create photon-pairs with a wide spectral bandwidth and a gated intensified camera to extract the image from the background noise. The high-dimensionality of the image space means that the information content can be many bits per detected photon, whereas the heralding photon can be restricted to a single spatial-mode within a secure fiber which itself could be protected against interception by traditional low-dimensionality quantum key protocols.

ORCID iDs

Johnson, Steven ORCID logoORCID: https://orcid.org/0000-0002-6181-8303, McMillan, Alex, Frick, Stefan, Rarity, John and Padgett, Miles;
CORE (COnnecting REpositories)