HDCP — Content Protection
Definition
HDCP (High-bandwidth Digital Content Protection) is a copy-protection system developed by Intel and licensed by Digital Content Protection LLC. It encrypts video on HDMI, DisplayPort, DVI and HDBaseT links, and each receiver has to authenticate with the source before protected content is sent. Version 2.2 is required for protected 4K Ultra HD content, for example by Netflix. The chain behind a source is limited: HDCP 2.2 accepts at most 32 devices and four levels of repeaters, against seven levels for HDCP 1.4. A non-compliant device anywhere in the chain, such as a splitter, a capture card or a scaler, makes authentication fail, and the display shows black or an error message.
In the field
A client laptop that gives a black screen through a capture card or a distribution chain is often blocked by HDCP. Professional presentation switchers and scalers manage HDCP negotiation, and many let the operator declare an input as not HDCP-capable, so that a laptop sends unprotected material such as slides without encryption. Consumer HDMI splitters are generally kept out of production chains because their HDCP handling varies from one model to another.
Related lessons
Sources
- Digital Content Protection LLC, HDCP 2.2 on HDMI Specification : authentification, répéteurs et gestion des clés · digital-cp.com
- Biamp, HDCP Management, HDCP 2.2 : 4 niveaux de répéteurs et 32 appareils par source ; HDCP 1.x : 7 niveaux · tesira-help.biamp.com
- Netflix Help Center, What is HDCP? HDCP 2.2 exigé pour la 4K Ultra HD · help.netflix.com
- Intel, Unable to Access or Play 4K Video on Netflix : ports et câbles HDMI certifiés HDCP 2.2 exigés pour la 4K · intel.com
- Extron, IN1606 Scaling Presentation Switcher : réglage « HDCP Authorized » désactivable par entrée HDMI, qui signale à la source une entrée non compatible HDCP pour transmettre un contenu non chiffré · extron.com