HDCP is the abbreviation for High-bandwidth Digital Content Protection. HDCP is a copy protection scheme to eliminate the possibility of intercepting digital data midstream between the source to the display.
The system is meant to stop HDCP-encrypted content from being played on unauthorized devices or devices which have been modified to copy HDCP content. Before sending data, a transmitting device checks that the receiver is authorized to receive it (Handshake). If so, the transmitter encrypts the data to prevent eavesdropping as it flows to the receiver
HDCP can cause problems for users who want to connect multiple screens to a device; for example, a bar, school or conference room with several televisions connected to one satellite receiver, DVD/BluRay or when a user has a closed laptop and uses an external display as the only monitor. HDCP devices can create multiple keys, allowing each screen to operate, but the number varies from device to device; e.g., a Dish or Sky satellite receiver can generate 16 keys. The technology sometimes causes handshaking problems where devices cannot establish a connection, especially with older high-definition displays