When it comes to protecting their premium content, over-the-top (OTT) providers require more than simply encryption for their films. They also need a safe licencing and decryption key handling mechanism. There needs to be more done than just encrypting high-quality videos for subscribers.
To ensure the safety of audiovisual assets in the OTT space is of paramount importance. The reason for this is the high demand for high quality material in the underground market. People who want to view popular TV series and movies but are unwilling to pay for the privilege do so in the grey market. In order to secure the exclusive rights to distribute high-quality content, market leaders like Netflix, Amazon Prime, Disney+, and others are willing to spend a lot of money. This has an impact on the firms’ bottom lines. This is so because it affects the profits made by the industry’s frontrunners. Because of this, the total revenue made by these industry frontrunners is impacted.
Over-the-top (OTT) providers encrypt video streams with a variety of Digital Rights Management (DRM) services and manage DRM licences from industry giants like Google’s Widevine, Apple’s FairPlay, and Microsoft’s PlayReady. One of the most prominent companies in this group is Apple Inc. Adding a video watermark to video files is one more way a trustworthy multi-DRM solution can protect them. This is an additional layer of protection. This makes it easier for the company to spot spots of vulnerability and implement fixes when they’re needed.
A large number of players use the AES-128 encryption standard to protect their video files, however they frequently experience difficulties keeping their decryption key secret. If the decryption key is not adequately protected, content leakage and unauthorised usage of video streams can occur even if the encryption standard is the best feasible. This is because the content could be illegally obtained through the use of unauthorised access to the video streams. The use of several DRM services is one strategy that OTT providers are considering to address this problem.
Digital Rights Management Has Increased Safety By Preventing Unauthorized Changes To Files
DRM, short for “digital rights management,” is a collection of features that includes encryption and decryption key distribution and administration as well as backend licencing servers. Management of digital rights is the complete term. The Advanced Encryption Standard (sometimes abbreviated “AES”) is the encryption method used by commercial digital rights management (DRM) systems. The premium content must be encrypted in such a way that it can only be decrypted using a key supplied by the OTT platform’s chosen third-party digital rights management provider. This method is classified as a symmetric key algorithm since it employs the same key for both the encipherment and decipherment processes. The majority of current encryption techniques use a symmetric key structure. The licencing server is where the encryption keys are kept safe when they are not in use.
Movie studios and other content providers often use AES cryptographic keys with 128 bits of encryption strength when protecting their media. The consumer must use the same key in order to access the video content for playback. One cannot avoid doing this. No one who does not physically hold the key will be able to access the website’s data. The server belonging to the multi-DRM service provider verifies that the user and the device in question are authorised to access the material before returning a licencing answer that comprises a decryption key.
Digital content should be packaged in an interoperable format, such as MPEG-DASH or HLS, due to the need for encryption to prevent its misuse or unauthorised playback. This will ensure that it cannot be exploited or played back illegally or without authorisation. This allows for decryption and proper playback of the encrypted data. This guarantees that the content can be decrypted whenever it’s needed. Some popular streaming protocols, such as MPEG-DASH and HLS, are built on top of HTTP to provide a more stable foundation. Both of these protocols are currently in development. The original files are encoded into a range of various adaptive streaming formats by applying a method known as cloud encoding. The encoder ensures file safety by encrypting them with keys derived from a variety of DRM vendors. This prevents any unauthorised parties from gaining access to the data.
The multi-DRM packager will seek an encryption key from the DRM system before it can encrypt any digital material. The multi-DRM packager will then get the encryption key from the DRM system. Widevine, developed by Google, is one such system. Following successful distribution via the DRM system, the encryption key will be automatically linked to the media content ID. In some cases, the encryption keys may be generated locally by the packager before being sent to the DRM system for safekeeping and subsequent distribution to the users. This may occur under specific conditions. For this reason, the DRM system follows the packager. The material will then be encrypted by the packager using the encryption key.
Since the client needs to decrypt the content before it can play it, this phase occurs before playback begins. By virtue of the digital rights management system, the consumer gets access to the decryption key for the video’s unique content ID, which was used during encryption. The goal was to safeguard individuals’ right to secrecy (DRM). The Content Decryption Module, often known as CDM for short, is a specialised piece of software that is normally built into the user’s device or web browser to decrypt encrypted content. This section is in charge of understanding the received data. CDM is preinstalled on all devices that support the Encrypted Media Extensions standard (EME). When the video is played, the player will have access to the decrypted content and can use it however they like.
A studio or content producer can utilise AES protection for their own content if they want to, but they may not be able to prevent hardware-based leakages or secure the transmission of AES keys between devices or between the server and the client device. This is owing to the fact that hardware-based leakages can only be fixed by the hardware manufacturer. This is owing to the fact that leaks created by hardware can only be addressed by an outside organisation that has access to the hardware in question. In order to close the gap that has been made, a multi-DRM approach is used when protecting video content using an AES layer.
Reasons why it’s crucial to employ both AES-CTR and AES-CBC configurations
Recently, the most popular DRM systems in the industry adopted Common Encryption (CENC), a standardised mechanism for protecting digital content. Using this technique, we can ensure the security of digital files. With the help of CENC, it is possible to encrypt a content file-set only once, allowing the content to be shared across several devices or platforms, each of which may apply a different DRM scheme. Both the cypher block chaining (CBC) and the counter (CTR) modes of operation are supported by the CENC encryption specification, which provides support for both of these modes.
These days, the most popular technique for block encryption is the Advanced Encryption Standard, also known as AES (AES). Block cyphers are a special form of protocol that can encrypt and decrypt data, two distinct but related processes. Any given block of plaintext can be used to generate ciphertext blocks of the same size as the plaintext block from which it was formed. The size of the encryption block that is presently being utilised is 128 bits, and it has always been this way. If you’re under attack from someone who’s using padding, one way to defend yourself is to switch to CBC mode. Many different methods exist for padding blocks when the plaintext does not supply enough of one. Similar to how the AES mode can be used to support a stream of plaintext, the cypher feedback (CFB), output feedback (OFB), and cypher text replay (CTR) modes all function. Cypher feedback (CFB) is a term used in combination with cypher text replay (OTR) and cypher output (OFB). The process of encrypting digital information involves the use of both AES-CTR and AES-CBC; however, the two techniques are not always compatible with one another due to the nature of the encryption they perform. This is the situation despite the fact that both modalities serve the same aim, which is to encrypt content for the purposes of security and allows decryption by a player with the use of DRM licencing. Protecting data by encrypting it is a common practise for security reasons. AES-CBC is the only cypher that is compatible with HLS and Apple devices and may be used to encrypt data.
During encryption, the video file will be mangled by an algorithm and rendered useless. This will make decryption of the data impossible. This is made possible with the use of a key, which is utilised alongside the method to encrypt and decrypt the digital data. Because of this, it is possible to decipher the data despite its encryption. Audio, video, and still images all have their own unique key, whether they’re recorded in standard definition (SD) or high definition (HD). Because of this, we classify the action of encrypting or decrypting a video file as a symmetric cryptographic operation.
Profiting from and making the most of several DRM systems
Video content secured by a DRM solution can be streamed and viewed by users, even when they’re not connected to the Internet. Solution as a service is a cloud-based infrastructure that handles digital rights management (DRM) for packaged material (SaaS). Both OTT game developers and digital content providers can take advantage of this service. This is accomplished through the use of the SPEKE API, and as a result, it is frequently already pre-integrated with useful cloud services like Amazon Web Services’ Elemental Media Services. You can use this to your advantage in a variety of contexts. This has shed light on the protocol utilised by individuals involved in media asset encryption and packaging to exchange information with those responsible for issuing digital rights management (DRM) keys.
