| 摘要 |
PROBLEM TO BE SOLVED: To guarantee rightful person's exercise of valid right concerned in digital contents. SOLUTION: Digital contents stored in a sales server 1a are ciphered contents ciphered by a contents producer's cipher key e.g. and in which charging information recording the charge of the contents and the payment destination of the charge is padded. In the case of copying read contents, contents reading software 13 included in a reading client 3a copies the ciphered contents in which the charging information is padded. Even at the time of receiving the copied ciphered contents in addition to the ciphered contents from the server 1a, the software 13 extracts the charging information and executes a settlement procedure for reading the contents. Then the software 13 requests the reading key for deciphering the contents to the server 1a, receives the reading key from the server 1a and deciphers the ciphered contents by using the received reading key. |
