| 摘要 |
In a database or a CATV system for charging a fee using a permit key, to prevent troubles, which may occur when there are too any requests for the permit key, the permit key is broadcast via data multiplex broadcasting or via data broadcasting. A user who wishes to use the database requests for use to a database host station. To this request, the database host station charges the fee for use and transmits an encrypted data. The user requested for use decrypts the encrypted data by the received permit key and uses the data. A viewer who wishes to view a scrambled CATV program requests for viewing to a CATV station. To this request, the CATV station charges the fee and transmits a scrambled picture. The viewer requested for viewing descrambles the scrambled picture by the received permit key and views the picture. <IMAGE> |
