Here is an example for you to have a brief understanding of how HDCP works.
If you have a HDTV and you want to watch a high definition DVD on it, then you connect the Blue-ray disc player to the TV with a HDMI cable. As a matter of fact, the moment you begin playing the HDCP-encrypted disc on your HDTV, the authentication process starts as well.
Here is the explanation of how HDCP works. Generally speaking, the transmitting device will send a ping to the receiving device, which is similar to the behavior of a submarine. If you want the signal to work all the time, then the receiving device has to return the ping the transmitting device within the limited period of time. Otherwise, the signal will stop and you have no opportunity to watch the high definition DVD any longer. Therefore, from the above-mentioned information, we can safely come to the conclusion that the key in such process lies in the return of the ping from the receiving device to the transmitting device.
In this example, the transmitting device is the Blue-ray player and the receiving device is the HDTV. As a result, things may end up in two totally different ways. If our HDTV is compatible with HDCP, then we are free to enjoy the high definition DVD as much as possible. However, if it is not HDCP-compatible, then the signal will be stopped and the movie won’t be played at all. Thus, all we are likely to get is either an error message or a blank screen.
According to the above-mentioned example, we can safely draw the conclusion that the most important factor in this process is that your device must be HDCP-compatible. Only in this way can the HDCP-encrypted content be played on the screen.