most five to 10 minutes of the event has been illegally redistributed.
Along with choking off a specific stream and the associated revenue, such actions should also have a longer term deterrent effect and steer people back towards legal sources. If users keep losing a stream just before a goal in a football match or a KO in boxing, they will switch to alternatives.
This comes back to the most important point of all, which is that watermarking by itself cannot enable infringing streams to be taken down in near real time, because it offers no way of detecting which ones are illicit in the first place. This requires a combination of other components of the ecosystem, in particular network forensic techniques and digital fingerprinting, which combine to identify streams that are clearly illicit.
Digital fingerprinting vs. watermarking Digital fingerprinting is often confused with watermarking, not helped by the fact that it is often wrongly associated with a technique also called on-screen messaging. Here a client device, typically a set-top box, displays an identifying number or text on top of the video for a short period, which is then transmitted with the stream. However, the message is not embedded in the video and can easily be countered by pirates simply by overlaying graphics on top of the message, so it has not gained wide traction, although has been used in some Indian pay-TV services.
Alternatively, genuine digital fingerprinting, as the name implies, involves taking a snapshot of specific video assets so that they can subsequently be identified economically in terms of computation without having to compare longer video sequences on a frame by frame basis. The main value then lies in recognising video sequences by their fingerprints, often in order to enforce copyright. Google’ s YouTube was one of the first major users of fingerprinting to identify and remove user generated video that violated the copyright claims of original owners, for example by incorporating elements of a movie.
Digital fingerprints are also used by systems that crawl the internet searching for streams that may be infringing, which is where the link with network forensics comes in. The aim is to identify anomalies that indicate a given stream may be an illicit retransmission, which could be when an account is permanently tuned into a given sports channel. This might show up as a single IP address continually streaming sports, which would be suspicious given it is highly unlikely one person would be watching a channel all day and every day. This would be strongly indicative that the channel was being restreamed illicitly and increased scrutiny can immediately be applied.
Digital fingerprinting can then identify specific assets being redistributed, although it might seem that this would not work so well for live sports because it takes time to generate a fingerprint and store it in the database for subsequent comparison. However, digital fingerprinting systems can now ingest and index live content online within a minute or two of broadcasting, which is quick enough for effective action to be taken such as taking down a live stream. Digital fingerprinting is already being used to identify copyrighted sporting highlights being uploaded on user generated content( UGC) sites while the actual event is still going on.
Watermarking is a complementary but distinct technique involving insertion of unique identifying features into specific streams or transmissions of media content, which can be done in principle at any point of the transmission system from head end to client device. This gives the potential to trace a specific stream back to any point at which a watermark was inserted. In the case of a stream that has just been identified as a likely candidate for being an illegal redistribution, extraction of watermarks in the content can trace it back to those sources where the marks were inserted.
Watermarking can then provide irrefutable evidence that content has been leaked and lays the foundation for further action. For a movie that action might involve suspension of subscription, or in the case of live sports, immediate deauthorisation of the source stream to a device.
Apart from counter piracy and deterrence, watermarking can also help enhance revenue and improve quality of service in various ways, by complementing DRM for online services in particular. For example, it can enable distribution of promotional content to devices without DRM, using watermarking to gain visibility over where and how that content is being accessed.
Importance of robust watermarking ecosystem Watermarking does introduce new complexities, which is why most operators will need a partner that can provide not just the core technology but also a complete ecosystem incorporating all the associated components, including network forensics and digital fingerprinting. That is why Verimatrix has established relationships with relevant leading partners in these fields, such as Friend MTS, whose content and platform protection services offer a comprehensive solution that protects against video piracy by accurately identifying and targeting, in real time, the source of illegitimate redistribution.
It is also important to consider that, just like any other security technology, watermarking itself will be subject to attack by pirates and hackers, seeking to disable or bypass the protection it provides. Watermarking is a new technology for most pay-TV operators and at this stage it is unclear exactly what form specific attacks on the system might take, but it is clear they will entail in some way altering marks so that they can no longer reveal sources of infringing streams.
It should also be possible to apply tools to identify where the attacks have taken place. Indeed, because the overall monitoring system is designed to be interactive so that it can discover possible redistributions and then extract watermarks in real time, it can also detect when the marks are under attack.
There are different types of watermarking techniques with varying levels of robustness, extraction performance and imperceptibility to the user, with the best choice depending on factors such as content value and whether it is live or on-demand. It all adds up to a lot of complexity which Verimatrix is easily able to handle with our VideoMark toolbox that offers a comprehensive spectrum of forensic watermarking and anti-piracy capabilities. With the diversity of challenges and opportunities in the digital video business environment, innovation in revenue security becomes of paramount importance. Watermarking is part of a multi-layered content protection strategy that can grow a service provider’ s competitive advantage by offering UHD content and unique OTT services.
Content Security 13