Encrypting and hiding UAV images with lossless carrier: an opto-electronic hybrid scheme based on 2D-CHSM chaotic system and multimodal biometric keys

Abstract With the growing demand for low-altitude unmanned aerial vehicle (UAV) applications across diverse industries, security concerns regarding the storage and transmission of UAV-captured images have become increasingly prominent. To safeguard UAV imagery during these processes, this paper proposes an optoelectronic hybrid encryption and hiding scheme specifically designed for UAV aerial images. In the proposed scheme, a novel chaotic system (2D-CHSM) is first employed to perform scrambling and diffusion on two plaintext UAV images. Subsequently, random phase masks generated from multimodal biometric features, and two-step phase-shifting digital holography are applied to encrypt the scrambled-diffused UAV images into two noise-like holograms. Finally, these two holograms are XORed with the canonical cosine transform (CCT) features of a carrier image that has also undergone scrambling and diffusion, thereby realizing optoelectronic hybrid encryption and lossless carrier-based hiding of UAV images. To validate the feasibility, security, and robustness of the proposed scheme, extensive numerical simulations were conducted on real UAV-captured images. The experimental results demonstrate that the proposed optoelectronic hybrid encryption and hiding scheme can effectively resist common attacks, including brute-force attacks, statistical analysis attacks, differential attacks, image processing attacks, noise attacks, and cropping attacks.