Color image encryption and hiding based on a three-dimensional chaotic system and canonical cosine transform

Currently, the so-called visually meaningful encryption schemes based on chaotic systems mainly achieve encryption by embedding noise-like pre-encrypted results into a carrier image. Therefore, these encryption schemes face the issues of limited embedding capacity and low security of the carrier image. To address these issues, this paper introduces a novel three-dimensional chaotic system, to our knowledge, and employs it to achieve a color image encryption and hiding scheme. In the proposed encryption and hiding scheme, the noise-like pre-encrypted results generated by the three-dimensional chaotic system are XORed with the encryption results of the canonical cosine transform features of the carrier image to generate a mapping key, which enables the encryption and hiding of color images. Since the proposed encryption and hiding scheme does not require modifying the carrier image, it effectively addresses the issues of limited embedding capacity inherent in traditional visually meaningful encryption schemes, as well as the low security of carrier images. Extensive numerical experiments and analysis demonstrate that the proposed encryption and hiding scheme for color images offers high security and robustness.