| 摘要 |
PURPOSE:To easily prevent a medium for storing electronic books from being illegally coped by providing a medium previously added an ID number corresponding to an ordering person, ciphering and deciphering information to be written in the medium for storing electronic books by using this ID number. CONSTITUTION:The ordering person of the electronic book connects its own IC card 7 to a terminal 4, activates the terminal 4 and orders the book. The read ID number is ciphered by the terminal 4 and stored in a cipher ID 42. Next, the terminal is connected to a center 4, and contents in the cipher ID 42 are transmitted through a high-speed line 3 to the center 1. The center 1 stores the contents of the cipher ID 42 transmitted from the terminal 4 in a cipher ID 11. Next, the contents of the cipher ID 11 are converted by a key generation algorithm 12 and stored in a key 13 and by this key 13, a source document is ciphered and transmitted to the terminal 4. After this ciphered document is temporarily stored in a ciphered document 45, the terminal 4 stores it in a file 5 for storing electronic books under the control of the terminal 4. When reading this file 5, the ciphered document is deciphered by the ID number of the IC card 7 and displayed on a display 6. |
