video watermarking


The rise of streaming platforms during the Covid-19 pandemic has brought focus on the piracy networks that have also flourished in each territory. The connected nature of the internet ensures that piracy of OTT shows has become widespread and immediate even if an OTT platform decides to withhold the releases in certain territories.

Content owners use digital rights management (DRM) and video watermarking as two prime ways to counter piracy. The DRM technology allows OTT platforms to authenticate playback sessions as per the subscription plan of the user. Credential sharing is a big problem in this industry. Through the DRM technology, OTT platforms can stem revenue leakage since they can put a cap on the number of devices being used through the same subscriber’s account.

The DRM technology allows content rights holders to encrypt each video asset, which stays encrypted throughout the distribution chain right till the client player. But, it needs to be decrypted before a playback session can begin. The content industry has managed to convince major web browsers to make a content decryption module (CDM) as part of their base offering. It adds the ease of access for encrypted content without there being a need to download any plugins to play the protected video content.

A web browser has another important set of security features in the form of Encrypted Media Extensions (EME), which is an industry standard about publishing DRM protected content in web browsers. EMEs allow a web player to initiate a license request from the licensing server, which could be Widevine, PlayReady, or FairPlay server depending upon the nature of the device. All decryption takes place with the CDM of the browser.

When a user requests a video file through their browser, the license acquisition process passes through EME where the playback client creates a key session unique to the client, device, and the metadata found in the video segments sought. A lot of this information becomes part of the forensic watermarks embedded in video segments released to the client. Since each watermark is unique, it can be extracted in the eventuality of a leak and the concerned user can be taken to task.