Reversible Information Hiding In Ciphertext Images Based On Huffman Coding And Channel Correlatio

With the development of digital technology and the abundance of information,the rapid development of cloud computing and big data has brought convenience to people,while security issues such as information privacy leakage have also occurred frequently.Therefore,reversible data hiding technology has emerged to protect user privacy.However,information embedding process may often damage the original image,and the hidden transmission may not be fully recovered.Cryptographic domain reversible data hiding is an effective cloud computing technology.It encrypts the carrier image during image transmission to ensure the confidentiality of the image content and hides secret information in the encrypted image to complete information exchange and transmission.This article focuses on the shortcomings of existing methods,such as embedding capacity,image perceptual quality,irrecoverability of carrier images,and greater demand for practical application of color images.Based on the principles of geometric correction,adaptive Huffman coding,color channel correlation of color images,and entropy coding,the reversible data hiding algorithm of ciphertext images is studied,improved,and enhanced.(1)To improve the imperceptibility,embedding capacity,and security of existing grayscale reversible data hiding methods,a high-performance reversible data hiding algorithm based on adaptive Huffman coding is proposed.First,the information owner encrypts the original image using a stream cipher XOR encryption algorithm.After preprocessing the original image,a large amount of secret information is embedded in the suitable embedding bit planes through adaptive Huffman coding,and then the security of the carrier image is further improved through scrambling algorithms.At the receiving end,the received carrier image is first decrypted and processed by geometric correction and other prediction algorithms,and then the secret information is extracted and the original image is restored based on the inverse process of information embedding.Experimental results show that compared with existing methods,this algorithm has better performance in terms of image quality,embedding capacity,and security,and can adaptively select the embedding capacity.The average embedding capacity is as high as 3.458 bpp,and the carrier image can be losslessly restored.(2)To improve the embedding capacity of existing color reversible data hiding methods due to the insufficient utilization of color channel correlation,a reversible data hiding algorithm for color ciphertext images based on RGB channel correlation and entropy coding is proposed.First,the three channels of the color image are separated,and the prediction error of the RGB channels is calculated separately.Then,the most suitable threshold is found through entropy coding in the prediction error,thereby obtaining the maximum storage space.On this basis,the storage space is further expanded through the correlation of RGB channels.After embedding information,the security of the color carrier image is enhanced through the cat mapping algorithm.At the receiving end,the carrier image is first decrypted,and then the secret information is extracted and the original image is restored based on the inverse process of information embedding.Experimental results show that compared with existing methods,this algorithm has better performance in terms of color image quality,embedding capacity,and security,with a maximum embedding capacity of 4.731 bpp for a single image and the ability to losslessly restore the carrier image.