Research On The Theory And Application Of Information Hiding

The multimedia data-hiding technique is a new research field developed in recent years in spite of the long history of other information hiding techniques. "The essential difference between this technology and cryptology is that the latter conceals the content of information itself while the former conceals the very existence of information. With the development of data-hiding technology, a wholly new approach with considerable developing foreground is exploited for the realm of information security technology.The research history of multimedia data-hiding technique is not very long and the study either on theory or on technique is not maturational at the present time, lacking systematic theory foundation and impartial uniform performance-testing and evaluating system. So it should be very meaningful to establish an integrated theory system to conclude some crucial problems and analyze them systematically.In this paper, a series of problems about the data-hiding theory and specific techniques are proposed, studied, resolved and concluded. Many aspects are concerned, such as the mathematic model of data-hiding system, the security of data-hiding system, the data-hiding capacity, the cryptographic key mechanism and etc. After making a deep research on audio frequency data-hiding algorithm and geometric attacks on image watermarking two adaptive audio data-hiding schemes and another robust image watermarking kernel algorithm for certification's forgery detection are proposed.The research results finished by the author independently during the Ph.D. studying process are listed as following.1. Give precise criterions and descriptions of some important concepts and disposals of data-hiding technique such as cover, stego-object, hiding information, data embedding, data extraction, stego-key, stego-analysis, insensibility, covert communication, digital watermarking, robustness and etc. Then propose a general mathematical model of data hiding which cover most models proposed in other papers and establish the basis for further theory analysis.2. Propose a matter-off-act information security hierarchy concept and attest the adequate and necessary existing condition of ideal secret communication system firstly. The research result can point out the orientation of designing a safe secret communication system. Then a further conclusion is testified that if the cover and the stego-object are acquainted with the attackers then the security of the system isspoiled.3. Advance two encryption schemes using chaotic dynamic system model which are respectively based on cat-mapping chaotic image encryption and binary generator of time-delaying infinite dimension chaotic system model. The simulation results can confirm the validity of these two schemes.4. Present an audio information segmental adaptive embedding scheme in DCT domain and test the validity of this scheme. Bring forward an adaptive data-hiding idea combing the HAS system and watermarking technique and design an audio adaptive watermarking algorithm based on HAS system. The simulation results are given out and also test the validity of this method.5. Bring forth an robust digital watermarking algorithm which has preferable robustness to slim geometric attacks such as shifting, cropping and rotation. It can play the crucial role in a digital watermarking certification' anti-forgery system.Finally a summary about the unsettled problems of data-hiding field is given out and a further research orientation in the future is also pointed out in the paper.