Research On Multiple Images Steganography

The rapid development of computer network and digital media technology brings great convenience to information transmission,but it also leads to various risks of information security.Image steganography hides secret information in cover images to realize secure transmission of secret information by using visual redundancy of digital images.And it is one of the research focuses in the field of information security.However,the researches of the traditional digital image steganography focus on the single cover image.With the coming of the era of big data,digital images are growing explosively on the internet.A steganographer could utilize multiple images to embed secret information simultaneously.Traditional steganography is facing new challenges.How to design secure and effective steganographic methods for multiple images steganography is an urgent problem.In this paper,we will study the embedding strategy and the embedding algorithm in multiple images steganography,and the main results are as follows:(1)Two embedding strategies based on image texture complexity and distortion statistical distribution are respectively designed for payload distribution in multiple image steganography.The former one estimates the maximum steganpgraphic capacity of each cover image depending on the texture complexity and size of the cover image,and embeds payload into fewer number of cover images.The sub-payload for each cover image is equal to its estimated capacity.This strategy can allocate more embedding payload for the more complex cover images.The latter strategy first calculates the embedding distortion value of each pixel in all cover images,and then assigns embedding payload according to the statistical distribution of embedding distortion values.This strategy can allocate more embedding payload for cover images with smaller distortion.Experimental results show that two proposed embedding strategies in multiple images steganography could obtain better performances against steganalysis.(2)A new multiple images steganographic scheme based on the dependencies of interblock coefficients in JPEG images is proposed for embedding secret information in multiple images steganography.The proposed steganographic scheme fully considers the mutual embedding impacts of inter-block neighboring coefficients.In the embedding process,the proposed scheme adjusts the cost values dynamically according to the modifications of inter-block neighbors,so as to make the modification of a coefficient be consistent with its inter-block neighbors as much as possible.Experimental results demonstrate that the proposed steganographic scheme can effectively aggregate the embedding changes of inter-block neighbors and keep the dependencies of inter-block coefficients unchanged.It performs better than the state-of-theart steganographic method in resisting the modern JPEG image steganalysis and the universal pooled steganalysis.