Digital home network and method for creating and updating such a network

A connecting confined digital network the display device (2 and 3), for receiving the data in a network, when the access device (1) is connected with the network, is provided with a network single encryption key into the encryption to the data, special, and display device comprises a positioning indication, for indicating display device for comprising a deciphering the data of receiving is provided with a network a key of communication special, a display device is a to receiver transmitting the decryption key is connected to the novel display device of network. The data encrypting and transmitting the network, and apparatus for single key on network, namely the network confined key and encryption and decryption to the data. Network confined key and a common key and a special for constituting. The network volume of the copy data in local area network, simultaneously relate to prevent the data illegal copy to the local area network.