Watermarking – The Anti-Piracy Champion Explained

In some regions of the world, stolen content represents as much as half of all video content consumed, according to analysts. The impact of illegal redistribution on the creative and sports industries is indisputable, leading to increased recognition from media organisations and content owners as to the importance of anti-piracy measures to safeguard content and revenue.

To combat the impact of illegal pirate operations, subscriber watermarking is now widely regarded as one of the most powerful solutions in the anti-piracy toolkit. By enabling pirated streams to be removed rapidly, watermarking enables legitimate content owners and distributors to control where their content and revenue flow. 

For distributors and broadcasters looking to integrate watermarking into their content security roadmap, there are a number of factors and deployment options to consider. Understanding how real-world attacks impact the performance and robustness of different solutions is a key factor in choosing the correct implementation.

Watermarking technology options

There are three primary approaches to watermarking: bitstream modification, server-side A/B variant, and client-composited. Each approach is applied differently and this has implications from a cost, performance and robustness perspective.

• Bitstream modification watermarking: watermark is applied either at the CDN edge or at the client-side. In both cases pre-processing of the video at the server-side is required. 
• A/B variant watermarking: watermark is applied at the server side in a single step with two watermarked copies of each stream made available on CDN. Subscriber-specific watermark information is then created from a unique pattern of adaptive video segments.
• Client-composited watermarking: watermark (an imperceptible overlay, agnostic to the video) is either generated at the client-side or at the server-side prior to being composited on top of the video at the client-side. 

Application and deployment of watermarking solutions 

Each type of watermarking solution has benefits and drawbacks that can affect its suitability for deployment in a specific environment. In terms of application, bitstream modification watermarking is primarily designed for set-tops providing access to either broadcast, IP, or OTT TV delivery methods, and the A/B variant solution is designed for adaptive streaming. Client-composited watermarking supports all of these delivery methods by design, as well as supporting both multicast and unicast streamed delivery.

When it comes to deployment, bitstream modification and A/B variant approaches introduce some challenges that do not impact client-composited watermarking in the same way. For example, bitstream modification has a high-compute overhead for pre-processing which makes it difficult to apply to live content. There is also an impact to latency, which is undesirable in modern low latency delivery environments, and therefore deployment is best limited to on-demand applications. 

A/B variant watermarking is also primarily optimised for on-demand content where fast watermark extraction isn’t imperative; it is less suitable, for example, for short-duration live content like a football game or boxing match.  As with the bitstream modification technique, the lack of parity across CDN and edge compute offerings makes streaming solutions using multi-CDN architecture complex. However, despite the requisite increase in infrastructure, server side watermark insertion can provide fewer external control points, e.g. specific watermarking integrations with multiple players and apps. 

Client-composited watermarking provides a different approach. The only subscriber watermarking technique designed ground-up for live content, client composited is optimised for protecting both live and on-demand content. The watermark is inserted at the client, which means that no pre-processing of content is required in the headend, and the processing overhead on the client itself is very low. In addition, financial and technical burdens are removed as no changes to content delivery workflows and expensive infrastructure are needed. However, there can be a technical overhead at the client end, as the watermarking technology has to be integrated into multiple players and apps.

It’s important to note that with all three of the watermarking approaches video must be fully secured as it’s in-flight to the client device using conditional access (CA) or digital rights management (DRM).  No watermarking solution can deliver effective security if the content signal isn’t fully protected and therefore open to interception or manipulation.

Speed of extraction

Once the watermark is in place, the next differentiator to consider is how quickly the watermark can be extracted in order to trigger remedial action. One major consideration is the duration of video required to extract the watermark. Both bitstream modification and A/B variant techniques require a relatively long duration of video to be captured and analysed. 

Client-composited solutions require considerably less video from which to enable extraction, delivering results in a timescale that suits faster-paced workflows. The speed of extraction, along with a simpler technical architecture, makes this type of watermarking much better suited for protecting live sports, for example.

Robust defense against attacks

To be an effective anti-piracy tool, watermarking must be extremely robust against attempts to tamper with or attack the image processing to remove the mark, which impacts the ability to identify the subscriber. This applies equally to all forms of watermarking.

When considering a watermarking solution, it’s important to assess it in the context of:

• your content type;
• your distribution model;
• your specific objectives. 

It’s also imperative that watermarking is considered as part of an overall, end-to-end content security platform. Like other security measures, watermarking can only be fully effective as part of this holistic approach. 

And finally, make sure that you consult a provider who is able to provide expert, agnostic and impartial advice, who will genuinely be able to guide you to the watermarking solution that is most appropriate for your unique environment and content.

To learn more about content and revenue protection or to schedule a demo, talk to one of our experts.

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