Simply explained: what is the protection of the HDCP copy?

HDCP means «high band protection with digital content» (in German «Protection of the digital content of high bandwidth») and indicates a digital encryption systemThe audio and video files protected by DVI, HDMI and the display door. The high -speed chipping process was developed by Intel in 2003 and is part of the HDMI connection. Here we explain how the protection of the HDCP copy works and technology is used.

1. How does HDCP work?

The HDCP system Based on cryptographic procedures and works with 40 keys for device. A transmitter and a recipient (for example a blue -ray blue reader and a smart TV or a computer and a monitor are combined and identify through «handshake» through their decoding chips. For this purpose, manufacturers have their devices certified by the Digital Content Protection LLC. From this you will therefore receive a 56 -bit key for the integrated decoder.

The decoding chips also prevent the abuse of HDCP, since the period of validity of the transmission key is determined. However, this can be modified (for example during the period of a film) if it has expired or an exchange of devices must be replaced.

The key part on the vehicle (for example the DVD or blue) is called «Multimedia key block“. In order for the reproduction device to be able to decipher the content, the other party is required, the «key block of the device» so called. This guarantees that the content subject to protection from copy cannot be cut from the outside.

Good to know: It may happen that DVI and HDMI devices do not find a common key and there is no transfer. In such cases, the problem can only be solved by replacing the DVI on an HDMI device.

2. Where do you use the protection of the HDCP copy?

In the film industry, HDCP is now a must for all HD devices. Blue ray discs are not reproduced without HDCP support. On the other hand, the television stations are mostly not encrypted. In the near future, however, a encrypted charism should also take place for all content.

All current televisions, HDTV boxes, DVD players or blue rays and even the game consoles are already equipped with corresponding decoding keys by default, of which more than one billion are available.

Cryptography does not change the video signals sent, it is used exclusively to open the video channel. The transmission of the image to HDCP takes place in high resolution and in excellent color quality.

HDCP 2.2 has been a recent copy protection since 2015. This has been optimized for the representation of the 4K content and is intended to protect the ultra HD content from the inadmissible reproduction. The new standard is mainly used in vod and streaming areas.

However, the prerequisite for the use of HDCP 2.2 is that all devices or components involved can also process the protocol (In addition to television, TV sticks, players and receivers, the reproduction chain also includes soundbar or speakers through which it is loose from the signal). Otherwise the screen remains black. In addition, the standard is not compatible downwards with the old HDCP 1.x encryption.

With HDCP 2.3, the successor of the current standard is already in the starting blocks, which must be used for the content with a resolution of up to 8K. Good to know: If your reproduction source supports HDCP 2.2, but your television still works with the old 1.4 protocol, copy protection can be managed using a bidirectional HDCP converter so called.