Network connection device, network connection method, and communication device realizing contents protection procedure over networks

A network connection device for connecting a first network and a second network, the first network supporting a use of one or more encryption keys for transmission and/or reception of encrypted data between nodes connected to a same network, and the second network supporting a use of an identical encryption key and a use of transmission and/or reception through a prescribed channel for transmission and/or reception of encrypted data between nodes connected to a same network, the network connection device comprising:

• a data reception unit connected to a bus of the first network configured to receive data transferred from a node connected on the first network;
• a data transfer unit connected to a bus of the second network configured to transfer the data received by the data reception unit to a node connected on the second network through the prescribed channel on the second network;
• an authentication request reception unit configured to receive an authentication request from one node connected on the second network;
• an encryption key information reception unit configured to receive an encryption key information regarding an encryption key for a specific data to be transferred to a specific channel on the second network from another node connected on the first network which is transmitting the specific data to the network connection device;
• and
• an encryption key information transfer unit configured to transfer the encryption key information to said one node, so as to facilitate a contents protection procedure between the transmission node and the reception node that are not connected to an identical network by using the authentication request and the encryption key information.

A communication device, connected to a first IEEE 1394 bus, for receiving data through a network connection device connected to the first IEEE 1394 bus from a transmission node on a second IEEE 1394 bus, the communication device comprising:

• a data reception unit configured to receive data transferred from the network connection device, through a first isochronous channel on the first IEEE 1394 bus;
• a query unit configured to make a query on information regarding the transmission node to the network connection device by using a prescribed packet on the first IEEE 1394 bus, when the data received by the data reception unit are encrypted;
• a reply reception unit configured to receive a reply to the query from the network connection device by using a prescribed packet on the first IEEE 1394 bus, the reply being obtained by the network connection device by making an inquiry on the information regarding the transmission node on the second IEEE 1394 bus upon receiving the query;
• and
• an authentication and key exchange processing unit configured to carry out an authentication and key exchange procedure directly with the transmission node on the second IEEE 1394 bus, according to the reply received by the reply reception unit, so as to facilitate a contents protection procedure with the transmission node that is not connected to an identical network by using the query and the reply.

A network connection method for connecting a first IEEE 1394 bus and a second IEEE 1394 bus, comprising the steps of:

• (a) transmitting data through a first isochronous channel from a transmission node on the first IEEE 1394 bus;
• (b) receiving the data transmitted from the transmission node through the first isochronous channel on the first IEEE 1394 bus at a network connection device, and transferring the data from the network connection device to a reception node on the second IEEE 1394 bus through a second isochronous channel on the second IEEE 1394 bus;
• (c) receiving the data transferred from the network connection device through the second isochronous channel on the second IEEE 1394 bus at the reception node, and when the data are encrypted, making a query on information regarding the transmission node from the reception node to the network connection device by using a prescribed packet on the second IEEE 1394 bus;
• (d) making an inquiry on the information regarding the transmission node from the network connection device to the transmission node by using a prescribed packet on the first IEEE 1394 bus, upon receiving the query from the reception node;
• (e) transmitting a reply to the inquiry from the transmission node to the network connection device by using a prescribed packet on the first IEEE 1394 bus, upon receiving the inquiry from the network connection device;
• and
• (f) notifying the reply from the network connection device to the reception node by using a prescribed packet on the second IEEE 1394 bus, upon receiving the reply from the transmission node, so as to facilitate a contents protection procedure between the transmission node and the reception node that are not connected to an identical network by using the query and the reply.