FDRM Architecture
4/8/2010
In the FDRM architecture, the Windows Mobile file-based Digital Rights Management (FDRM) API provides the interface for communication between FDRM-enabled applications and the FDRM engine.
When protected content is downloaded to the device, the FDRM engine encrypts the content and stores the rights associated with the content in the rights store. When a user requests access to protected content through an FDRM-enabled application, the application invokes the FDRM API to initially verify rights to the content and then to commit the right to be used, such as the right to play audio or video content. By implementing the FDRM API functions called by the application, the FDRM engine can either confirm or deny the type of access requested and display the appropriate UI. If access is granted, the engine decrypts the content for display or use by the application.
The FDRM engine interacts directly with the file system. The file system filter provided by the FDRM engine intercepts calls to the file system and checks to see whether the requested file is DRM protected.
The following illustration shows the FDRM architecture with examples of applications that can be FDRM-enabled.
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The highlights in the diagram indicate which components are provided by Microsoft and which components are provided by OEMs.
OMA Generic Content Download Over The Air (OTA) is another OMA specification, it is optional in the OMA DRM V1 specification.
In the architectural diagram, the dotted box encircling OMA Generic Content Download OTA indicates that it is an optional component that must be provided by the FDRM engine provider if the mobile operator requires this functionality. If OMA Generic Content Download OTA is required by the operator, then the client functionality provided by the FDRM engine provider must download all such content to the device.