By Laurent Piron, Principal Solution Architect, NAGRA and chairman of the Ultra HD Forum security working group
Forensic watermarking is now being required by holders of premium rights to movies and increasingly also live sports. This trend has been gathering force ever since MovieLabs announced it was recommending forensic watermarking be mandated for content distributed by its member studios in Ultra HD formats in April 2014. This now means content created at High Dynamic Range (HDR), Wide Color Gamut (WCG) and High Frame Rate (HFR) as well as 2160p “4K” resolutions. Forensic watermarking will be required for premium content with these attributes.
Furthermore, although the Ultra HD forum is naturally focused on the security of UHD content, it recognizes that forensic watermarking will also be required for early release window movies, as well as to provide a new line of defense against illicit redistribution over the Internet in general. Indeed, the Forum has made sure that its guidelines for deployment of forensic watermarking are equally applicable to all content, irrespective of the format.
The Ultra HD Forum Security Working Group (WG) has dedicated its first efforts to forensic watermarking because the technology is still at a formative stage and yet, at the same time, is now an absolute requirement for UHD content from the studios, which will not release the most premium content without that protection. This is because the main piracy threat in the Internet era is illicit content redistribution of content using various IP-based technologies, which can only be dealt with by identifying individual streams and tracing them back to their source. This in turn requires insertion of some unique identifier at the source or during distribution. A watermark can be designed to be tamper resistant and at the same time to have minimal impact on the video or audio quality, although there is a balance to be struck between robustness, performance and transparency to the user.
The Ultra HD Forum has identified strong demand from the infrastructure community that it represents, not just for information about use cases, applications and the technology itself, but also for guidance on deployment and integration. Technology providers are under pressure to incorporate forensic watermarking in their products from the ground up because the MovieLabs mandate has prompted a change in mindset towards security in general so that it is taken seriously again and no longer bolted on almost as an afterthought. Now it should be one of the first considerations at the specification and design stages.
This immediately means that the different watermarking systems should be compatible as much as possible and interoperate within delivery ecosystems. That is why the Ultra HD Forum has defined guidelines that specify not just a common vocabulary and systems architecture, but also key integration points, including the encoder, CDN and client device, where marks can be embedded. The guidelines also describe requirements on the ecosystem side, again with a view to ensuring that forensic watermarking is catered for from the beginning.
The Forum is fortunate to have many of the principal forensic watermarking technology providers as members: Content Armor, NexGuard (acquired by NAGRA in 2016), Verimatrix and most recently, Irdeto. The guidelines therefore represent their collective wisdom and cater for all possible use cases and deployment scenarios. At the same time these vendors can ensure their products are aligned with security requirements for Ultra HD content.
The focus of the current guidelines is very much on deploying forensic watermarking now, but it is still a work in progress with more to be done over the coming months. The WG has had interesting and valuable feedback from various parties, especially from streaming providers as well as content creators such as Sony Pictures, and some of that will be incorporated in the next version of the guidelines. That will make it even easier to integrate forensic watermarking through a unique interface, which currently is still being worked out with the different technology providers.
The underlying point is that OTT distribution has changed the security game, presenting new threats and making unauthorized content available in many different places for easy access by users, many of whom are normally law abiding but still happily consume pirated material. Ultra HD ups the ante by increasing the value of the content but also by making it easier to redistribute at high quality over the Internet. Existing content protection mechanisms can readily be bypassed, possibly by direct camcording from a screen, although a greater threat is through direct capture of streams using illegal tools that circumvent the protection provided by HDCP over the HDMI interfaces to TVs.
In this context, forensic watermarking has become a critical component that must be integrated within the ecosystem to ensure end-to-end content and revenue protection. The Ultra HD Forum guidelines are designed to facilitate and accelerate this integration and will be available on www.ultrahdforum.org from April 24th.