Research Of Application On Audio Digital Watermarking In Digital Rights Management

With the development of Internet, people communicate by digital information, such as electronic presses and multimedia files. Since digital information can be duplicated easily, the illegal distributions of copyrighted digital objects become extensive. The benefits of the rights holders have been infringed. Digital Rights Management technology which is developed as a protection against the illegal distribution of copyrighted online material is very important.DRM technology adopts the access mechanism of hardware and software to control the use of digital information in cycle life. It includes description, identification, trading, monitor, tracing for permission of tangible and intangible asserts and relationship management of copyright holders.There are two kinds of technology for copyrights protection. One is based on cryptology;another is based on digital watermarking technology. Cryptology is used for controlling the illegal duplication and distribution. Digital watermarking is used for hiding copyrights data which can provide evidences when the copyrights dissension occurs. For the moment, most business DRM systems are based on cryptology. The digital watermarking technology is one of the research focuses in recent years, and it will be more and more important in copyrights protection.In transform domain, the algorithm of audio digital watermark is researched. In DCT domain, the watermark is embedded in audio information based on coefficients quantification. Beside, gray image is selected as watermark. In DWT domain, an adaptive audio digital watermark algorithm is adopted. The modulated signal is embedded in the coefficients with relatively large absolute value on middle frequency range detail signal adaptively. It can improve the robustness and imperceptibility of the algorithm. Simulate experiments are carried out.Based on chaos theory, the gray image as watermark is encrypted. Chaos theory is one kind of the cryptology. It can be used for digital copyright protection in order to improve security. The gray watermark image is pre-processed by chaotic sequenceand magic permutation, and then is embedded in audio digital DCT domain.The algorithm of audio digital no-watermark is studied in DWT domain. The watermark is not embedded in audio digital information. The watermark information is created according to the coefficients feature of audio. The audio digital information doesn't change and the algorithm is simple. Simulate experiments can prove the robustness and imperceptibility.