| 摘要 |
PURPOSE:To provide an information distribution system capable of performing a primary and a secondary distribution of paid information and preventing damage from reaching equipments other than the terminal equipment even when the physical safety of the terminal is not guaranteed any more. CONSTITUTION:In this information distribution system for distributing digital information from a supply station 101 to the plural terminals 103 among the terminals 103 through an information transmission medium, the supply station 101 is provided with a means for outputting ciphered information for which the information is ciphered by a first cryptographic key intrinsic to the respective pieces of the information and a distribution key for which a first deciphering key corresponding to the first cryptographic key is ciphered by a second cryptographic key intrinsic to a reception terminal to the medium. The respective terminals 103 are provided with the means for inputting the ciphered information and the distribution key transmitted from the supply station 101 or the other terminal through the medium, the means for deciphering the ciphered information by the first deciphering key extracted by deciphering the distribution key by a second deciphering key corresponding to the second cryptographic key, the means for ciphering the first deciphering key extracted by deciphering the encipherment distribution key by the second deciphering key by the second cryptographic key intrinsic to the terminal which is the transmission destination of the ciphered information and the means for outputting the distribution key obtained by the means and the ciphered information to the medium. |
