The Design Of DRM System For Vedio And Audio

Because of the resistance by the consumer in the application process, the digital rights management technology of multimedia has been given up by many commercial companies. But as an effective method which can balance the interests in the digital industry chain, DRM technology is not obsolete. Oppositely, it is more necessary to design a more rational business model and more practical systems to enable consumers accept this technology more easily.After the description of the basic digital rights management system framework and some common multimedia DRM technology, three principles of digital rights management system, including safety, practicality and low coupling, are proposed. According to the principles, several key issues are found during the design of the system. And some achievable solutions are given then. These issues include the package method of multi-media files, the selection of strategies to secure local rights object, and so on. The encryption method of multimedia package based on the structure is chosen, rather than the method based on codec. To protect the local rights objects, key, which is used to encrypt the object, is calculated dynamically. The strategy to get the key can be set and changed in the server. The strategy identifier is packaged in the license and resolved by the client. The client can get the key by calculation according to the strategy stored in license.In order to assess the security of digital rights management system, a model, which is based on AHP, is proposed. Not only the anti-attack capability of the system is considered in the model, but the ability to recover after system attack is also put into consideration. The anti-attack capability of the system is determined by three factors:the way media content is encrypted, the security of the data transmission and the protection of local rights. The last factor is proposed because of the fact in security area that no matter how secure a system is, it will be compromised one day. The ability to recover after system being attacked also plays a vital role. Two factors should be taken into consideration to measure the recovery ability of the system:the controllability of media's copyright, the system operating mechanism of recoverability.DRM piracy tracking technology, mentioned in this paper, can track the media content by fingerprints that embedded in media files. It can deter the abuse of digital rights, so it's a good direction for DRM. The combination of the piracy tracking technology and usage control technology can protect digital rights of multimedia more effectively.