An Efficient Key Distribution Method Applying to OMA DRM 2.0 with Device Identifier

As digital contents are increasingly used on mobile devices, digital rights management(DRM) application will become a core component of mobile terminals. OMA DRM, invented by the open mobile alliance (OMA), is the most widely available mobile DRM standard. Following a general description about OMA DRM 2.0, this paper gives a detailed analysis about cryptographic operations and Rights Objects acquisition. To reduce processing time and energy consumption in mobile terminal, previous papers mentioned to substitute asymmetric algorithm with symmetric algorithm on the protection of rights encryption key(K_REK). However, security analysis did not resolve. In this paper, we firstly make a comparison of asymmetric and symmetric algorithm on processing time, and then proposed using device identifier as symmetric encryption key to substitute asymmetric algorithm. Protection and distribution of symmetric encryption key are presented in the end.