How Protected Content Is Used

Applications obtain use licenses from RMS servers to access protected content. Shown here is a scenario in which a user edits a protected document with Word 2003. The scenario proceeds as follows:

(1)The user opens the protected document in Word.

(2) Word requests a use license for the document from the RMS client.

(3) The RMS client requests a use license from the RMS server. The request includes the user’s Rights Management Account Certificate, a digital certificate previously issued to the user by RMS that enables the user to access protected content on the specific computer. The request also includes the publishing license associated with the document. The publishing license includes the content key for the document encrypted with the RMS server’s public key, and it is digitally signed by the content author.

(4) The RMS server validates the content author’s digital signature on the publishing license. It determines what rights the user has to the document, according to the Extensible Rights Markup Language (XrML) rights in the publishing license. If the user has rights, the RMS server uses its own private key to decrypt the content key for the document. It then re-encrypts the content key with the public key from the user’s Rights Management Account Certificate. This action ensures that the content key can be accessed only by that particular user. The RMS server places the encrypted content key into a use license along with a description of the user’s rights, and digitally signs the use license. It then returns the new use license to the RMS client.