Introduction
Although analog audio and video content has its advantages, digital audio and video (hereinafter referred to as DAV) has gained great popularity associated with the constant improvement of quality, the development of consumer devices that reproduce such content, etc. But how easy it is to reproduce DAB, it is also easy to copy and illegally distribute it. The entertainment industry has a need for digital copy protection. To solve this problem, manufacturers have developed schemes and components for protection against digital copying and distribution. An example of such technologies is HDCP, developed by Intel. HDCP (from English High-bandwidth Digital Content Protection - “High-bandwidth digital content protection”) is a media content protection technology designed to prevent copying of high-quality video transmitted over DVI (HDCP is optional for this interface), DisplayPort (HDCP is mandatory for this interface), HDMI, GVIF or UDI. The protected video signal can only be played back on equipment that supports HDCP. The HDCP 1.x encryption system was finally cracked in 2010 (the system master key was restored).
HDCP is used to protect the transmission of DAB content from a video source such as a computer, satellite box or DVD player to a receiver such as a display. This encryption system is designed to prevent playback of HDCP-encrypted content on devices that do not support HDCP or that have been compromised to copy such content. Before sending the data, the transmitting device checks whether the recipient is entitled to receive it. If so, the transmitter encrypts the data to prevent eavesdropping when transmitting digital data to the receiver. Several different HDCP-compliant interfaces can be used to connect the source to the target device.
This article describes the HDCP device. In one embodiment, an HDCP device includes: (1) a transmitter configured to deliver DAB content over a communications channel to an authorized HDCP receiver, (2) an acknowledgment device configured to determine if an authenticated HDCP receiver is also a trusted device and allows only delivery or he can forward the content to someone else. And also, the method of delivery of DAC, as well as its encryption, will be revealed. It includes: (1) obtaining an encryption key from a potential DAB receiver, (2) identifying potential HDCP compliant receivers, (3) in addition to authentication, verification of potential receivers by a device for receiving DAB content.
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So, today, I think that this is not the most reliable protection, but which is used.
List of sources:
1) HDMI Explained by Rob Carter
2) Digital Content Protection LLC. HDCP specification v1.4