Protecting Your Content


Most security measures protect content by controlling access to it, such as through an access control list (ACL) on a network share. Windows Media Rights Manager, on the other hand, protects a Windows Media file or stream by securing the data itself through encryption. In order to play an encrypted stream, an end user obtains a license that contains the key for decrypting the data. By tying issuance of a license to receiving a fee or some other criteria, you can maintain tight control over who has access to your content and how it is used. In that sense, Windows Media Rights Manager can become an important part of a business model.

There are other ways to secure data. Some methods, such as hiding the URL, are not secure enough for a business model. Methods like these can only work if the content that is being hidden has no value for anyone except those who already have the URL. If your content has market value and you need to restrict access to it, then you need to implement a truly secure system.

A more secure method would be to use the Windows Media server to apply authentication and authorization to a publishing point, or to an individual file or stream. Then give end users who pay a fee permission to access the content. This type of system has been used for pay-per-view scenarios. The system works fine, but it can be cumbersome to maintain. For one thing, you need access to the server in order to update the permissions list. For many content providers, such as Contoso Movies Online, obtaining permission from a hosting service to access security on a Windows Media server might not be possible.

More importantly, authentication and authorization only secure the path to the content. If the content is moved or copied to a location that is not secure, the content is vulnerable. There are also applications available that capture streams to local files. If an end user had one of these programs, all she would have to do is pay to access the stream, and then record it to her hard drive. Then she could freely make copies and distribute the file. And of course, authentication and authorization does nothing to protect files that are downloaded or distributed on CDs, for example.

Windows Media Rights Manager protects the content itself. No matter where you locate the file or what you do with it, the file remains protected. You can, for example, distribute protected files on a CD for free or encourage end users to share files. End users can have the protected content, but they will not be able to play the files until they receive a license, and for that you can charge a fee.

Of course, a revenue model is only one use for Windows Media Rights Manager. A corporation could use rights management to restrict who can view sensitive company information. For example, rights management could be used for business-to-business communication to restrict viewing of a live conference over the Internet. And again, simply having knowledge of the URL or of a valid user name and password will not enable a user to view a Windows Media Rights Manager-protected stream, because the content itself is encrypted.




Microsoft Windows Media Resource Kit
Microsoft Windows Media Resource Kit (Pro-Resource Kit)
ISBN: 0735618070
EAN: 2147483647
Year: 2005
Pages: 258

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