What is DRM?
Digital rights management (DRM) is a digital licensing system that allows content copyright owners to monitor how and by whom their content is used and restrict the ways the content is copied or propagated by the end user. DRM technology protects the copyrights of electronic media and ensures that publishers receive legitimate revenue for their content. It is used by over-the-top (OTT) platforms, such as Netflix, Hulu, and Amazon Prime, from Video DRM industry leaders, such as Microsoft’s PlayReady, Google’s Widevine, and Apple’s FairPlay. DRM technology helps manage and protect digital content across desktops, smartphones, smart TVs, gaming consoles, ebook readers, casting sticks, and other smart devices. For example, Netflix uses Microsoft’s PlayReady DRM system, among others, along with Video watermarking to prevent any illegal content leakage and limit the number of users accessing a specific premium digital content.
DRM Content Packaging
DRM media content packaging encrypts and protects the original content from illegal use. DRM content packaging is the method of encryption of the source content into formats such as Dynamic Adaptive Streaming over HTTP (DASH) or HTTP Live Streaming (HLS). Since the Moving Picture Expert Group (MPEG) has developed the DASH format, it is also called MPEG-DASH. Advanced Encryption Standard (AES) has become the standard encryption algorithm for encrypting digital content of these formats. The encrypted content is delivered to the end user’s device. A DRM license with the encryption key issued from a DRM license server is needed by the customer to playback the content; this process is managed by a multi-DRM service.
AES-128 is an encryption standard in which each block size is 128 bits. It is considered a strong encryption standard, so much so that even the American intelligence agency National Security Agency recommends this standard for encrypting top communication. Video protection technologies, be they HLS, Adobe’s Real Time Messaging Protocol, or DRM-protected content, use AES-128 to encrypt video files. Industry leaders believe that without accessing the decryption key, hackers cannot break into files encrypted with AES-128 standards. AES uses the same key for encrypting and decrypting content since it is a symmetric key algorithm.
In the HLS method, each video file is encrypted as blocks. Each block is encrypted with the ciphertext of the previous block. This chain cipher method protects the video file and ensures that each block is separately decrypted at the client device.
The AES algorithm is a strong method to encrypt a video file, but it does allow a leakage point in the form of unsecure decryption key, which may not lie in a protected space in the client device or the end user may choose to share it with unauthorized users. OTT players are aware of this lacuna and, thus, protect their content with a multi-DRM service which ensures a secured delivery of license key to the client. A robust multi-DRM SaaS that handles DRMs licenses issued by the global leaders like Widevine is, therefore, indispensable for the OTT industry.