| 摘要 |
PURPOSE:To provide a method and a system for digital information communication which protect the copy right by enabling a specific regular user group consisting of plural members to freely make a copy for backup or use information in terminals other than the reception terminal with respect to chargeable digital information received and purchased by communication use and preventing the illegal use of groups other than the regular user group for the purpose of protecting the right of a copyright holder and an information presenter. CONSTITUTION:A card 2 which has a security information storage part 21 where the user identification number different by cards, is provided only one group secret key set to a group in common, etc., are stored, and the card 2 and a terminal equipment 3 are connected, and the user identification number stored in the card 2 is transmitted from the terminal equipment 3 to an information center device 1 to request the information, and the received information main body is enciphered with the group secret key and is stored in the terminal equipment 3, and the information main body is deciphered by the group secret key when being used. |
