A New Rights Processing Method for DRM Systems

There are many solutions and standards about digital rights management(DRM) now. Almost all the solutions used cryptography and rights processing technologies to protect contents. Only legal users can decrypt and enjoy contents under the control of rights information, illegal users are prohibited. Rights processing technologies include rights expression languages (REL), binary encoding method, virtual machine, and so on. ODRL (Open Digital Rights Language) and XrML (eXtensible Markup Language) are all RELs, which express rights based on XML. Broadcasting flag encodes copy control information into binary data block. Marlin DRM uses Plankton virtual machine to process rights information. In this paper, we provided a rights processing method which is based on ASN.1(Abstract Syntax Notation One) syntax and using ASN.1 distinguishable encoding rule (DER) to encode rights information into binary data block. Compared with RELs, this rights processing method uses less bits to express rights information and can save more bandwidth during transmission. And it can express more rights information than broadcast flag.