DRM-protected content in the OTT segment is further protected by forensic watermarking. Malicious attackers, on the other hand, frequently discover weaknesses in watermarking techniques and use them to their advantage.
A common type of attack on video watermarking is collusion. Multiple videos with identical watermarks are used in a collaboration attack. It is possible for the attacker to extract and identify the watermark’s pattern this way, and then combine the various copies of content to obscure it. Using multiple copies of a work with different watermarks, an adversary may be able to make the watermarks undetectable by combining the watermarks on all of the copies.
Even in DRM protected content, the watermark payload bits can be spread out across multiple domains to prevent collusion attacks. Error correction codes can also be used to identify the mark even if it has been tampered with. As a general rule, anti-collusion techniques are more effective when more payload bits are retrieved from the content. Afterwards, the payload must be formatted to prevent compromise by collusion-based attacks. Video bits shared or combined by attackers are emphasised because of the “marking assumption” that these bits will be preserved in any averaging approach. This could include a device type, a time stamp if the copies were made at the same time, or a geographic location if the attackers are located close by. Attacks utilising gradient descent can be thwarted by obscuring any information that could be used to determine a direct route out of the detection area.
The scene is represented just by its 2D projection, which are photos acquired by cameras. It is possible to watermark image sequences that record a 3D scene and extract the watermark from any rendered image generated for any arbitrary view angle, as opposed to the first two methods, which only protect the watermark information for the two key components of 3D scene representation (geometry and texture). If you’re using dynamic watermarking, you may embed information on the video asset while it’s being played back at the user’s end, such as the user’s email, date and time of watching, their IP address, or even their business logo. Because of their dynamic nature, they provide additional protection for confidential content that is not intended to be shared or altered. DAI (dynamic ad insertion) is also activated via dynamic watermarking in order to optimise addressable ad income.
DRM video protection techniques such as watermarks are not sufficient on their own, but when used in conjunction with other measures, they can help to safeguard the intellectual property of the content owner and aid to trace the source of any alleged infringement. They also serve as a helpful reminder to users about their own and others’ rights to the content they’re using.
The number of transactions assigned to a single user can also be reduced by repeating the same transaction number for a predetermined period of time. The user would thus receive the same payload for any access to the same content within the specified time frame, which would prevent collusion between copies of a single user. Additionally, a high payload bitrate could aid in enhancing anti-collusion measures. This can be controlled by the adaptive bitrate segment duration in some two-step watermarking implementations or made a property of the watermarking technology itself.