INFORMATION DISTRIBUTING DEVICE, RECEIVING DEVICE AND COMMUNICATION METHOD

摘要

PROBLEM TO BE SOLVED: To extend copy protection technique to a digital contents circulation by executing a transport protocol processing required for transferring contents information, creating a basic transport header which indicates that contents information is enciphered and transmitting a packet including desired information to a communication opposite party by way of a network. SOLUTION: MPEG4 data outputted from an MPEG4 data creating part 301 are enciphered by a data enciphering part 302. An authentication and key exchange processing part 311 generates a new cipher key for an enciphering processing in the case of the updating timing of the cipher key and gives it to the data enciphering part 302. Together with it, the value of information to be a source for generating a common key is increased and given to the part 302. The value of information to be the source for generating the common key is given from the part 302 to a cipher extension header giving part 304. An MPEG4 extending header is exempted from a ciphering object.