Today we are going to review what HDCP is and explain how does it work. It is a content protection protocol that you can find in televisions and external players. Normally, many of the devices connected with cables such as HDMI will use this type of protection, and both the devices where the content is played and the TVs will have to be compatible.
Let’s start by explaining what this protocol is and what does it serve as clearly as we can. And then, we will try to explain how does it work. As you will see, it is not a very extensive article, so you will soon find it easy to understand.
What is HDCP?
HDCP stands for High-bandwidth Digital Content Protection. It is a security protocol for digital content developed by Intel, whose purpose is to prevent the copying of content through interfaces such as DVI or HDMI, among others.
It encrypts the information that travels from one device to another. HDCP-certified devices have a master key that serves to encrypt and decrypt the contents, a key that is only provided to authorized manufacturers.
This way, the protocol acts as a DRM, limiting uncontrolled access to content in order to protect copyright. Thanks to this, both the movies you buy on Bluray or DVD, as well as cable TV content or some streaming services ensure that it is more difficult to copy their content. Of course, we all know that nowadays this is something that cannot be stopped, but it does make it more difficult.
How does HDCP work?
Normally, to play video or audio we need two things: a player (our Bluray player, for example) and a viewer (our television). When we play a video, for example, the reader and the viewer will identify themselves with that HDCP key and will encrypt the data that is being sent.
Then, only authorized devices will be able to receive and they will not be able to copy it. We could say that the HDCP key is the identification to enter a club where nobody copies content and this club is the only place that you can watch that movie.
If we do not meet the requirements, in this case, it is the master key provided by HDCP, we do not enter the club and we will not be able to watch the movie. The HDCP protocol is updated over time to reinforce its security so that it does not become obsolete.