Research On The Digital Image Information Hiding Technique Based On Human Visual System

With the development of the internet,information technology has been widely applied in various professions, which make a great contribution for economy, politics, military and culture. However in the same time, global, open , shared and dynamic network system makes digital information more vulnerable than before intentionally or unintentionally to be attacked. Once the digital information gets the damage, for example, information is illegal eavesdropped, interceped, changed or damaged in the transmission, storage and processing procedure. It will bring immeasurable loss for the users. Therefore, the information security system is facing severe challenges, which has become a major problem for national security, economic development and personal interests. Under this situation, how to make use of the internet convenient and ensure the safe of information has become the focus of the people. Traditional password theory is not enough to meet modern information security technology needs. The development of information hiding technology provides a fresh way of safely, quickly and effectively and using digital information and it becomes an important research direction in information security area. Therefore research on information hiding technology is an important and meaningful work.People pay more and more interests to image for it's figure, intuitive, huge information. So imsge has been to one of the major information sources. More and more experts and scholars pay attention to the development of image processing. Thus we discuss mainly about the information hiding technology based on digital image in this paper.This paper briefly reviews the history of information hiding and introduces the related concepts, principles, etc. On this basis, research and discussion of the digital image scrambling hiding technology, based on the LSB airspace information hiding techniques, and based on sharing information hiding technology. Many algorithms are proposed. The main work in the thesis is as follows:(1) Introduce an image scrambling method based on two-random function, based on sequences of the unpredictability and the initial value sensitivity. First of all, this paper produced a one-dimensional random sequence by seed, reuse sequence before and after the location of each element in the one-to-one relationship, implementation of the pixel position scrambling, which can realize pixel position scrambling and pixel value scrambling at the same time. The algorithm bears nice scrambling capability and security, which is easy to realize and no iteration need. Its efficiency is proved by mass experiments. The results show that the algorithm has application value in the field of secret image storage and transmission.(2) Present a math property about recoverability of the given sequence exchange. With this new property, we put forward a new digital image scrambling and encryption algorithm, thus give the principle and detailed method. And evaluate the immunity and scrambling degree and so on. Its efficiency is proved by mass experiment, the results of the analysis indicate that the algorithm bears nice scrambling capability and security, be easy to realize, and difficult for the attacker to decode. This algorithm has application value in the field of secret image storage and transmission and this mathematical conclusion can be used in the widest area.(3) Ascertain the position of embedding bytes according to the size of cover image, embedding capacity and random function, in order to distribute the embedding information evenly. We discuss the properties of XOR operation and the features of bit planes, then decide whether or not change bit by the XOR value of the embedding bits, and then realize the secret information hiding. The algorithm make the two secret information bits embed into a pixel at one time, but only need change one bit at most. The new scheme can enhance the embedding capacity and security of secret information and the secret information can be recovered with no change. The experimental results show that this method is available and efficient.(4) Present an algorithm of hidden information based on matching: First, the secret information are turned to binary sequences, then fix the inserted position through computing the matching rate between the secret sequence and the carrier sequence. If the rate is low, we change to use the secret sequence's antithetic sequence to carry out matching. Or the secret sequence is divided into groups, each of which contains three bits. With the results of comparing the encrypted information with the embedded image's low bits, the different bits of each group are changed and the information is embedded. When the secret is extracted, the flag bits are read after the finding of the embedded location, and then the secret was found by the sign. The algorithm is easy to realize and insure in the worst situation the matching rate achieve 50%. With the same embedded quantity, the new algorithm obtains less altered bits, the more the matching rate is and the less the carrier image be modified, the better the secret information be hided. The experimental results show that this algorithm has large hidden information capacity, good hidden effect and a certain practical value.(5) Present a new method of digital image sharing. Firstly, construct a reversible matrix, decompose the secret image into several scrambling and encryption images at one time by matrix operation, then camouflage them into several enlarge and meaningful carrier images to store or transfer. This algorithm combines the scrambling technique, encryption technique, information hiding and sharing technique, but with much simpler algorithm, less computation time, smaller pixel expansion, better recovery effect and more difficultly for the attacker to decode. The results show that the algorithm possesses application value in the field of secret image storage and transmission.(6) Present a new method of digital image sharing based LSB. Firstly, turn the secret information into the one-dimensional sequence, and then the sequence's value and position is scrambled using double random number and cryptology principle. Secondly, divide the scrambling sequence into several sections, and camouflage them into sizable carrier image to realize the secret information sharing. This algorithm combines the encryption technique, scrambling technique, information hiding and sharing technique, but with much simpler algorithm, less computation time, smaller pixel expansion, better recovery effect and more difficultly for the attacker to decode. The results show that the algorithm has application value in the field of secret image storage and transmission.