3.1.1.7 License Management

If the transmitter and receiver are performing license management using license chains, the transmitter will send the receiver a root license. If the transmitter sends the receiver a root license during the license retrieval procedure, then it MUST send a leaf license to the receiver. The process of delivering a leaf license to the receiver is called license management using license chains, because the rights and restrictions are formed through the chained policy (1).

The root and leaf licenses form a license chain that contains the current set of rights and restrictions. The receiver MUST adhere to the most restrictive policies contained in the licenses, whether those policies come from the root license or the leaf license.

Sections 3.2.5.5.1 and 3.3.5.5.1 specify rules and requirements for root and leaf licenses that MUST be followed during license management using license chains.

If the transmitter and receiver are performing license management using license derivation data, a base license MUST be created.

Sections 3.2.5.5.2 and 3.3.5.5.2 specify rules and requirements for base licenses that MUST be followed during license management using license derivation data.

The transmitter MAY perform the license management procedure multiple times. This allows the policies that are associated with the content to be updated dynamically.

If content is being transferred over HTTP and the content is not encapsulated in ASF [ASF], then the transmitter MUST implement license management as specified in this section

When RTSP is used, license management is implemented by delivering the license update messages using ANNOUNCE requests, as specified in section 2.1.1.3  RTSP License Management.

When MPEG TS is used, license management is implemented by delivering the license update message using TAG packets.

Revocation List Update

A revocation list identifies software or hardware components to which protected content MUST no longer flow . Different content protection systems have different formats for revocation lists. WMDRM: Network Devices Protocol supports distributing revocation lists for different content protection systems through the revocation list update procedure. The receiver MAY use this procedure to obtain the latest version of the RIV structure. The receiver MAY use this procedure to obtain the latest revocation list for different content protection systems.

Section 2.2.1.6 includes the various content protection systems for which revocation lists might be available. The RIV GUIDS section specifies the GUID used to identify revocation lists for each system. RIV Structure also defines a GUID for the RIV structure. The receiver MUST use that GUID when it sends a revocation list request message to obtain the latest version of the RIV structure.

Revocation list update is not supported for transmitters acting as an OpenCable Unidirectional Receiver (OCUR).

Authenticated Commands: The authenticated commands procedure allows sending cryptographically signed commands from the receiver to the transmitter. The authenticated commands are needed to control the PBDA hardware tuner.