WM DRM Revocation
There are several ways to carry out revocation, so that the user is no longer able to playback the media file. Revocation
mechanisms can be as granular as revoking an individual DRM security
component or as broad as refusing license issuance to a class of
EZDRM.com has implemented a license revocation feature, which allows our clients to revoke a license for a specific file or all of the license issued to a specific user. For more information, check out our Windows Media DRM page.
Three different revocation concepts described below:
- Content Revocation: Content
providers can revoke specific content from the user's machine
by issuing a license with a content revocation key. The content
revocation key is the public key used to sign the header of the
content. When a content provider wants to revoke the content,
the content provider adds the public key to the revocation list
in the license. This feature is therefore enforced by the licensing
- Player Application Exclusion:
Player exclusion is a feature that allows a license issuer to
prevent specific player applications from playing certain packaged
files. This feature is enforced on the client by the license.
When generating a license for a packaged file, the license issuer
specifies the ID for the player application to exclude. The result
is that consumers cannot play the packaged file on the excluded
player application. The benefit to this feature is that the excluded
player application is not affected. It is only prevented from
using the packaged files.
- Protected Content Manager Exclusion:
Players that work with packaged files contain a Protected Content
Manager, which encrypts and decrypts the content and enforces
the rights in licenses. Protected Content Manager exclusion is
a feature that allows you to identify player applications that
are based on a compromised Protected Content Manager. This feature
is enforced by the licensing server. Microsoft publishes a Protected
Content Manager exclusion list that license issuers must obtain
and periodically update. Then, if a license issuer receives a
license request from a player that is based on an excluded Protected
Content Manager, the license issuer can refuse to issue a license.
Instead, the license issuer can display a link for downloading
a new player or upgrade.