| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technology for distributing a file in safety by preventing unjust leakage/distribution efficiently without issuing a digital certification for every file. <P>SOLUTION: An encryption device generates a decryption key by using destination information corresponding to a terminal, and transmits the decryption key to a decryption key distribution unit together with the destination information. The decryption key distribution unit stores them in a data storage means while associating with each other. The encryption device generates an encryption file by encrypting a file, adds regulation information being referred in order to perform a predetermined regulation processing for the encryption file at the terminal to the encryption file, and delivers the encryption file to which the regulation information is added on a communication network. The decryption key distribution unit receives a decryption key request including the digital certification and the destination information from the terminal, verifies the digital certification and transmits a decryption key corresponding to the destination information included in the decryption key request received from the terminal to that terminal. <P>COPYRIGHT: (C)2008,JPO&INPIT |
