TECH CORNER

Creating a secure yet flexible home viewing experience

Consumers nowadays expect to access their content seamlessly across different devices, without being limited by digital rights management (DRM) issues. Whether on your PC or your TV, once you’ve paid for it, you want to view it at any time, anywhere and from any device.

Service providers, and cable operators in particular, have realised this. Many are reviewing their set-top box strategies to move towards a media gateway – including PCs and portable media players – within the home for more flexible viewing experiences. The media gateway should be able to accommodate a variety of consumer demands, including:

• Digital video recorders (DVR) capabilities to digitally store content for later viewing
• Video on Demand (VOD) – especially catch-up services
• Using the internet to deliver content – over-the-top services
• Home domain – turning the set-top box into part of a media centre to incorporate multiple devices

While service providers haven’t yet reached agreement on the characteristic architecture of the media gateway and its connected clients, having an adequate and flexible security solution will be key for its success – not only to meet content providers’ security requirements but also to gain user acceptance.

Conditional access system (CAS) solutions need to provide more persistent security and more flexible usage rules to meet these challenges. Nagravision has already deployed a security solution to address these needs – NAGRA Media PRM (persistent rights management).

What is NAGRA Media PRM?

NAGRA Media PRM (persistent rights management) is the security for VOD and DVRs based on NAGRA on-chip security (NOCS). It’s independent of the CAS and is deployed as a standalone component. On the PC, a software security implementation of NAGRA Media PRM is integrated with NAGRA Media PLAYER.

While choosing a content protection approach is a challenge for operators, PRM can leverage the large install base of NOCS STBs and broad range of NOCS chipsets. Rather than dealing with interoperability challenges of so-called interoperable DRMs, PRM can be easily deployed to a wide range of existing and new set-top boxes.

NAGRA Media PRM lets the operator control content consumption and distribution via several kinds of services, including:

• Streamed VOD, pull and push VOD – pre-encrypted content is delivered to the video server, regardless of the type of content delivery network (CDN) in place
• DVR recording and playback – live content is re-scrambled and stored on the hard disk drive (HDD), controlled by PRM.

The following components make up NAGRA Media PRM:

• DVS – DVR & VOD server which is also known as the licence server
• VOD pre-encryption component, which includes:
  - WFM – workflow manager
  - CPS – content pre-encryption station
• DVL – DVR & VOD library – the client library on the set-top box
• NOCS – to provide a hardware root of trust

These components can be seamlessly integrated into the operator’s ecosystem, either as a standalone security product or as part of an end-to-end solution.

Viewers are offered different business models that are managed by the operator’s portal or service delivery platform (SDP). The SDP manages the purchase transaction with the viewer, obtains the licence from the PRM licence server (DVS) and delivers it to the client device. In cases where the operator doesn’t already operate a SDP, the NAGRA Media SDP can be bundled with the NAGRA Media PRM as a pre-integrated solution.

Securing DVR today to create the ‘authorised domain’ tomorrow

As well as supporting VOD, NAGRA Media PRM is the solution of choice for content protection on DVR set-top boxes. Upgrading current DVRs with the PRM solution doesn’t just lay the foundations for future home networking and authorised domain solutions. It also enables unique features which are particularly valued by operators using external storage. These include:

• HDD refurbishment – if authorised by the operator, content recorded by one DVR can be played back on another DVR. This feature is particularly popular as it means subscribers can keep content even if they have to replace their original set-top box.
• Simple home domain – in the same way, several set-top boxes can be authorised to read and write content on the same storage layer, enabling HDD mobility in a sneakernet mode. This means PRM lets you play content recorded by a DVR set-top box on another STB in another room. It is the advent of the first ‘authorised domain’.

To conclude …

While the focus so far has been on VOD, NAGRA Media PRM is today also a preferred solution for DVR security. Adding PRM to the DVR will not only offer operators unique advantages over legacy DVR security solutions, but will provide a seamless transition to the ‘authorised domain’ of the future.