How HDCP protects your digital content transmission

How HDCP protects your digital content transmission

High-Bandwidth Digital Content Protection, or HDCP, is a specification developed by Intel to protect digital content from being intercepted as it travels from one device to another. HDCP-compliant devices use unique sets of encryption keys to securely communicate with one another.

Early HDCP 1.x standards protected data moving across DVI, HDMI, DisplayPort, GVIF and UDI connections. However, they did not support transmission of data across networks. The 2.x standards support transmission over any IP-based interface but limit transmission to a maximum of 32 devices. A new standard, HDCP 2.2 Pro, will allow commercial AV networks to connect more devices—potentially an unlimited number.

Protected source devices include set-top boxes, DVD and Blu-ray players and computer graphics cards. Receiving devices include televisions, digital projectors, video walls and computer monitors. In addition to the end devices being HDCP compliant, all devices in between must be as well. These include switches, converters, repeaters, splitters and distribution amplifiers.

How it works

HDCP uses an exchange of encryption keys between the source and the display to ensure that compliant devices will only communicate with other compliant devices. Each HDCP-compatible device contains a unique set of 40 56-bit keys as well as a special public key called a Key Selection Vector, or KSV.

Before transmitting any digital content, the transmitter and receiver exchange KSVs. The receiver will only accept content if it receives the correct KSV from the transmitter. Once the connection is established, the KSVs combine with the devices’ unique keys to create an encrypted connection. This secure connection is constantly monitored to verify the transmission. For additional protection, the transmitter encrypts the digital content before sending it. The receiver decrypts it on the other end.

Licensed equipment

All HDCP-compatible equipment is licensed by Digital Content Protection. This licensing ensures that manufacturers take adequate steps to protect transmitted content or risk losing their license. Only trustworthy devices are licensed. If a device breaks the terms of the license agreement, its KSV can be added to a revocation list so future transmitters will refuse to send to the revoked device.

Because HDCP technology relies on encryption keys stored within each device, no product without these keys will work as an HDCP-compliant device. In the case of incompatibility, the display may show an error message or a snowy image.

Black Box offers a range of HDCP-compatible equipment to ensure you can securely transmit digital content without unauthorized individuals and devices accessing your data. Contact us today to learn your options.