Patent ID: 7324644

Claim:
A transmitting device for transmitting copyright protected contents data to a receiving device through radio communications the transmitting device comprising: a first authentication unit configured to carry out a first authentication with the receiving device, for judging whether the receiving device is a device that is allowed to communicate with the transmitting device or not, on a radio link layer of the radio communications; a first key exchange unit configured to generate a first encryption key and share the first encryption key with the receiving device when the first authentication with the receiving device by the first authentication unit is successful; a second authentication unit configured to carry out a second authentication with the receiving device, for protecting copyright of the contents data to be transmitted, through an encrypted radio communication using the first encryption key; a second key exchange unit configured to generate a second encryption key and share the second encryption key with the receiving device when the second authentication with the receiving device by the second authentication unit is successful; and a communication unit configured to transmit the contents data to the receiving device through an encrypted communication path which is encrypted by using the second encryption key and provided on the radio link layer, wherein at least one of the second authentication unit and the second key exchange unit rejects its process of at least one of authentication and key exchange with the receiving device when at least one of the first authentication by the first authentication unit and the first key exchange by the first key exchange unit with the receiving device is unsuccessful.