Reversible data hiding in encrypted images based on IWT and chaotic system

In this paper, a reversible data hiding in encrypted image (RDH-EI) algorithm based on integer wavelet transform (IWT) and chaotic system was proposed. The image decrypted and the extracted data by the algorithm were both lossless. In this scheme, IWT transform was used to decompose the carrier image into wavelet components, and the chaotic system was used to generate position sequence, encryption sequence and scrambling sequence, which were used for data hiding and image encryption. The secret data was hidden in the diagonal component according to the position sequence, and the approximate component was encrypted according to the encryption sequence and the scrambling sequence, and then the final encrypted image was obtained. A solution was proposed to solve the problem of pixel loss in the reconstruction process after the wavelet component is encrypted. The key used to decrypt the image and extract the secret information was divided into two parts for different levels of security considerations. The method of encrypting image after data hiding made the solution more secure and with higher maximum payload. Simulation results showed that, compared with some existing schemes, this scheme could obtain better performance, which including higher embedding rate, visual quality of decrypted and extracted images, and anti-attack performance.