1.3 Overview

Digital Rights Management (DRM) version 1, version 7, and version 11 provide a means of acquiring a license for Windows Media content.

When using Digital Rights Management Version 1, the client generates a license request and sends it to a license server as an HTTP GET request. The server receives the GET request and returns the license to the client embedded within an HTML page.

Digital Rights Management Version 7 uses a packet containing a license request in extensible markup language (XML) format and is sent using an HTTP POST request. The server responds with an XML packet containing any number and combination of version 1 and version 7 licenses.

Digital Rights Management Version 11 is functionally equivalent to the version 7 protocol, with the addition of a few XML fields in the license request challenge body.

In all versions of the license protocol, the intent is to document the protocol for acquisition of licenses in which the license details themselves are not technically relevant to the protocol.  License formats are described in detail for completeness, however.

The following table describes cryptographic and mathematical operators. For more information, see [NSPCPW].

Operator	Description
cryptographic operator "K{text}"	Text encrypted with symmetric key K.
cryptographic operator "[text] K"	Text signed with private portion of asymmetric key K, Kpriv.
cryptographic operator "{text}K"	Text encrypted with public portion of asymmetric key K, Kpub.
mathematical operator "□"	A bitwise exclusive OR.
mathematical operator "~"	A bitwise negation.
mathematical operator "|"	A concatenation.