About Windows Media Rights Manager
Applies To: Windows Server 2008, Windows Server 2008 R2
Windows Media Rights Manager is a digital rights management (DRM) platform that can be used by content providers and retailers to distribute digital media files securely over a network, such as the Internet. The Windows Media Rights Manager SDK helps protect digital media content (such as songs and videos) by packaging Windows Media files in an encrypted file format. A packaged file contains a version of a "protected" file that was encrypted and locked with a "key" after business usage and distribution rules were added to the content header. This packaged file is also bundled with additional information from the content provider and, optionally, from the distributor. The result is a protected Windows Media file that can only be played by a user who has obtained a license.
The basic Windows Media Rights Manager process is as follows:
Protecting. The content owner or content provider adds business usage and distribution rules to the content. (For example, this process could include setting the playback count rights, the license validity duration, or the ability of the distributor to update specific usage rules.) After the file is protected, it can only be used or opened by specified users. For commercially distributed files, the content owner can include "Anyone" as a user, but can specify that certain distributors can change one or more of the usage rules to meet their business requirements. Typically, the content provider then sends the protected file to the distributor for packaging.
Packaging. The distributor packages the digital media file using Windows Media Rights Manager. The packaged file has been encrypted and locked with a "key." This key is stored in an encrypted license, which is distributed separately. Other information is added to the file, such as the URL where the license can be acquired. This protected file is saved in Windows Media Audio format (.wma file name extension) or Windows Media Video format (.wmv file name extension).
Distribution. The protected file can be placed on a Web site for download, placed on a server for streaming, distributed on a CD, or e-mailed to users. Windows Media Rights Manager permits users to send copy-protected files to friends, as well. The distribution rules are set by the content owner and the distributor according to their desired business rules.
Establishing a license server. The content provider chooses a clearinghouse that stores the specific rights or rules of the license and implements the Windows Media Rights Manager license services. The role of the clearinghouse is to authenticate the customer's request for a license. Files and licenses are distributed and stored separately, making it easier to manage the entire system.
License acquisition. To play a protected file, the user must first acquire a license key to unlock the file. The process of acquiring a license begins automatically when the user tries to acquire the protected content, acquires a predelivered license, or plays the file for the first time. Windows Media Rights Manager either sends the user to a registration page where information is requested or payment is required, or "silently" retrieves a license from a clearinghouse.
Playing the file. To play the file, the user needs a player that supports Windows Media Rights Manager. Support for Windows Media Rights Manager was first added to Windows Media Player for Windows XP. Players that were created using the Windows Media Player ActiveX control version 8 or later also support this DRM platform. With the appropriate version of the Player installed, the customer can then play the file according to the rules or rights that are included in the license. Licenses can have different rights, such as start times and dates, duration, and counted operations. For instance, default rights may allow the user to play the file on a specific computer and copy the file to a portable device. Licenses, however, are not transferable. If a customer sends a protected file to a friend, this friend must acquire a different license to play the file. This per-computer licensing scheme ensures that the protected file can only be played by the computer that has been granted the license key for that file.