Research On Reversible Data Hiding Algorithm Based On Translation Of Difference Histogram

With the development of network communication technology,digital media are widely disseminated through the Internet.However,malicious tampering and illegal copying that may occur in the process of information dissemination threaten the intellectual property rights,personal privacy and even military secrets of digital media.However,digital image has become one of the most important information carriers by virtue of its intuitive and vivid features.How to ensure the security of digital image in transmission and storage has become an urgent problem to be solved.Reversible data hiding technology is a branch of information security field,different from the traditional cryptography,information hiding is through embedding information into public digital image,and doesn't affect the use of the image at the same time,the confidentiality of the existence of secret information,is not easy to attract the attention of the attacker to ensure information security of the image.Encryption technology and reversible data hiding technology are not contradictory in fact,they can double protect the image from different angles.In the application process,the reversible data hiding in encrypted domain is a scheme that has both advantages.It is of great practical significance to carry out reversible data hiding directly in ciphertext images to meet specific requirements.This paper mainly includes the following aspects:(1)Existing information hiding algorithms are analyzed and summarized,and evaluation criteria of different types of information hiding are discussed.In this paper,LSB algorithm,spread algorithm and histogram translation algorithm are introduced in detail,and common image encryption algorithms are briefly explained to pave the way for finding the combination of encryption technology and reversible data hiding technology.(2)Points out the flaws of the existing difference histogram algorithm and make improvements,first of all,the image preprocessing method is modified,for reducing the number of additional information embedded in space,and then proposed a new grouping scheme for more difference directly and finally sorted by pixel position combined with the corresponding modification scheme,reduce the image changes.Experimental results show that the hidden image quality has been significantly improved and the algorithm is completely reversible,which can restore the carrier image 100%.(3)Combining homomorphic encryption and block difference histogram algorithm,a large-capacity ciphertext domain reversible data hiding algorithm is proposed.Using additive homomorphic encryption mechanism,make the difference histogram can directly in the cipher domain,according to the image block size effect the performance of the algorithm,we design a dynamic block difference depends on the length of the secret information acquisition method,and then to the edge of the block difference histogram values for multi-layer embedding,broke the difference histogram peak of embedding capacity.The experimental results show that the image quality of the direct decryption algorithm is good,and the embedding capacity is high.