How License Revocation Works

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How License Revocation Works

To revoke licenses, the license issuer must develop a client-side application, such as an ActiveX control, based on the Windows Media Format 9.5 SDK. This client-side application will communicate with the Windows Media License Service during the license revocation process, as follows:

  1. The process of license revocation is initiated. For example, the consumer visits the Web site for their content service and requests to deactivate their computer.

  2. The client-side application, using its own implementation, creates a machine ID for the consumer's client computer. The client-side application passes the machine ID and any additional custom metadata to the DRM component of the player. (At this time, only a user ID is supported.)

  3. The client-side application creates a transaction ID, and sends it along with the machine ID, the custom data, and the client computer's public key to the licensing server as a license revocation challenge.

  4. Using the information in the challenge, the licensing server creates a license revocation response that indicates which licenses to revoke, and sends it to the client. For example, the licensing server could specify a key ID and a custom user ID—licenses that contain both values would be deleted.

    Note   The licensing server can only revoke licenses that it has issued.

  5. The client processes this response by deleting the licenses that meet the conditions that were specified.

  6. The client generates a license revocation acknowledgement and sends it back to the licensing server to confirm that the licenses were deleted.

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