HDCP – What is HDCP? What’s the use of it?
HDCP is an encryption technology, similar to a lock, used to ensure the transmission and playback of digital content. HDCP stands for High bandwidth Digital Content Protection, which stands for High bandwidth Digital Content Protection. HDMI is a high-definition digital interface standard that provides high bandwidth and lossless transmission of digital video and audio signals. In order to ensure that high-definition signals transmitted by HDMI or DVI are not illegally recorded, HDCP technology has emerged.
The HDCP technology specification, led by Intel, is an important anti piracy technology developed for high-definition movies and TV programs to ensure that digital image and sound data are not illegally copied when sent through DVI or HDMI interfaces. The specifications of HDCP are protected by multiple patent rights, and anyone who wishes to implement HDCP must apply for authorization.
For example, if you want to play HDCP protected audio and video content such as Blu rayDisc or PlayStation games (when outputted through HDMI), both the signal source (player or computer graphics card) and the monitor (TV or projector) must have an HDCP key chip built-in in order to play properly. If either party of the system is not equipped with this key chip, the image quality may decrease, and even the image cannot be played.
The technical principles of HDCP
The main goal of HDCP is to prevent unencrypted high-definition audio and video content from being illegally copied and transmitted. Three systems were designed in HDCP to achieve this goal:
1. Verify the protocol. A verification process to prevent unauthorized devices from receiving high-definition content.
2. Pixel encryption. Encrypt data transmitted through interfaces such as HDMI and DVI to prevent data theft or cracking.
3. Upgradability. A key revocation mechanism to ensure that any device that violates the HDCP protocol can be relatively easily excluded.
During the HDCP transmission process, both the sender and receiver store a set of available keys, which are secret stored. Both the sender and receiver perform encryption and decryption operations based on the keys, and a special value KSV (video encryption key) is also added to such operations. At the same time, each device in HDCP will have a unique KSV serial number, and the password processing units of the sender and receiver will verify each other’s KSV values to ensure that the connection is legal.