| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To make it impossible to refer to file contents in an environment other than an environment in which the file contents should be referred to or preserved essentially. <P>SOLUTION: A text as the encryption object is encrypted with an encryption algorithm and an encryption key to generate an encrypted file, and dependent files having dependence on the encrypted file are designated, and a key for encrypting the encryption key is generated on the basis of the position information of the dependent files, and key information including an encryption key encrypted by the generated key and the information of the dependent files is generated. The identifier of the encryption algorithm and the key information are stored in the encrypted file, and the positional information of one or a plurality of dependent files is taken out of the encrypted file having the key information stored therein. Decoding key information for the encryption key is generated by the positional information of successfully acquired dependent files only when dependent files present in logical positions indicated by the positional information are successfully acquired, and the encryption key is decoded by the decoding key information, and the text in the encrypted file is decoded by the decoded encryption key. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
