Research On Reversible Data Hiding Method For Encrypted Color Images

With the rapid development of computer network communication and multimedia technology,multimedia image data has been widely used by more applications.In order to realize covert communication well and achieve the security of image data transmission,usually the images are encrypted first and then the data hiding technology is applied.Therefore,the reversible data hiding technology based on the encrypted image has become a research hotspot in recent years,which is widely applied in some fields include military,medicine and law.Aiming at the shortcomings of the existing methods,such as the imbalance of embedding capacity,image perception quality and robustness,or the more practical applications requirement of color images,using two-dimensional chaotic encryption,discrete cosine transform and block histogram translation technology principle to study the reversible data hiding algorithm of color images in encrypted domain.The detailed research contents are as follows:1.In order to improve the imperceptibility,robustness and embedding capacity of existing reversible data hiding method for encrypted images,a robust reversible data hiding algorithm for encrypted color images was proposed.The color image was encrypted by Logistic chaotic xor encryption algorithm,which was segmented into blocks and performed by two-dimensional discrete cosine transform.The low-frequency part with good robustness was selected to embed secret information in order to improve the anti-attack ability of the algorithm.Finally,the method of complementary pixels was used to embed large-capacity secret information.At the receiving end,the encrypted image was decrypted and the secret information was extracted according to the inverse process of information embedding and the original image was restored.The experimental results show that the proposed algorithm has better performance in image quality,embedding capacity,robustness and encryption effection and can choose the embedding capacity adaptively.When the embedding capacity reaches 1.15 bpp the average peak signal-to-noise ratio can reach 39.39 dB.2.In order to improve the embedding capacity and image perception quality of existing algorithms,an adaptive reversible data hiding algorithm for encrypted color image was proposed.Firstly,the color image was encrypted by Logistic chaotic scrambling encryption algorithm.Then,the encrypted image blocks were adaptively divided into smooth blocks and steep blocks according to the set fluctuation threshold,and then high-plane bit replacement was performed on the smooth block,and histogram shifting was performed on the steep block to embed mult bits to improve embedding capacity and image quality.The experimental results show that the proposed algorithm has high embedding capacity and image perception quality.When the embedding capacity is 1.142 bpp,the peak signal-to-noise ratio(PSNR)can reach more than 30 dB,and the robustness is better when performing noise and shear attacks.