Invertible Secret Image Sharing with Authentication for Embedding Color Palette Image into True Color Image

Invertible secret image sharing with authentication (ISISA) distributes comprehensible stego images generated from secret images and cover images to involved participants. The secret image and cover image can be correctly recovered after authentication. However, existing ISISA schemes suffer from issues such as a single kind of image, limited embedding capacity, poor visual quality and a lack of authentication capability. To address these issues, this paper provides a novel invertible secret image sharing scheme with authentication for embedding color palette images into true color images. In this scheme, the pixels of the palette secret image and the bits of the cover pixel are used as coefficients of the polynomial. Share is embedded into a true color cover image to generate an intermediate stego image. Authentication information is then derived from the intermediate stego image and hidden in the cover image. The final stego images that resemble the cover image are obtained and sent to authorized participants. At the receiver end, once k stego images are verified, the secret image and cover image can be losslessly recovered for a (
k
,
n
)-threshold scheme. The experimental results and theoretical analysis demonstrated the superiority and practicality of the scheme.