Optical color image encryption by wavelength multiplexing and lensless Fresnel transform holograms

TLDR

The paper proposes a novel color image encryption method using wavelength multiplexing with lensless Fresnel transform holograms. The method splits the image into RGB channels, encrypts each with a Fresnel transform and random phase mask whose parameters serve as keys, and supports both multichannel and single‑channel optical implementations with iterative key addition. Simulations demonstrate the feasibility of the proposed encryption scheme.

Abstract

We propose what we believe is a new method for color image encryption by use of wavelength multiplexing based on lensless Fresnel transform holograms. An image is separated into three channels: red, green, and blue, and each channel is independently encrypted. The system parameters of Fresnel transforms and random phase masks in each channel are keys in image encryption and decryption. An optical color image coding configuration with multichannel implementation and an optoelectronic color image encryption architecture with single-channel implementation are presented. The keys can be added by iteratively employing the Fresnel transforms. Computer simulations are given to prove the possibility of the proposed idea.