Research On Digital Rights Management Based On Cryptography And Digital Watermarking

With the development of Internet and electronic commerce, a great deal of pirate and tort exists in digital content which spread on Internet. Therefore, it is insistent to protect copyright of digital content. But present technology and system of the digital rights management have a great of shortages and limitations. In traditional cryptography, some shortcomings and vulnerabilities usually exist in identity authentication or rights control stage, and it will be very difficult to protect the rights after the digital product is decoded. In addition, digital watermark technology can be used to take evidence and track the illegal user when piracy happens, but it is hard to prevent it beforehand. These questions greatly restrict the development of electronic commerce and business affairs of digital content.On the basis of researches about the present technology and system of digital rights management, this text uses technique that combines cryptography and watermark to deeply research DRM technology, and provides a better solution to the DRM problem. Main research results of the thesis are as follows:1. A new DRM protecting mode based on cryptography and watermark is proposed under considering actual needs for digital rights entities and security risk. It mainly includes copyright registration, embedding watermark, online business, authentication and arbitration, and can provide many kinds of services. The protocols for the mode is also presented, the mode and its protocols can resist many algorithm attacks, provide good security and practicability.2. About rights control, this text uses a new method based on machine fingerprint, and it binds content license with machine fingerprint and user identity. Then, a new method of structuring the license key and distributing the license is proposed, which prevent nonlicet and legal users from getting the license key. Legal users can only use the client software to use digital commodity according to the demand of license, but not get original text of digital content.3. Give specific design and implementation of the content distribution server in content provider side, and the special client software in user side.The DRM system mentioned in this text is based on cryptography and digital watermark technology. On one hand,it can effective protect the interests of the copyright owner; on the other hand,it can track pirate and tort activities and find direct infringer, so that the author and the distributor have more confidence in creation and publish business, and it promote the transaction and dissemination of the digital content.