| 摘要 |
PROBLEM TO BE SOLVED: To enable an information user to decode information signals even with an unregistered decoder device if necessary, and to enable an information supplier to recognize that the user has obtained information using the unregistered decoder device and specify the unregistered decoder device. SOLUTION: The information supplier 1 registers the ID number of the decode device 11a in advance. When a decoder device 11 with a different ID number is used, the ID number of the decoder device 11 is recorded in the IC card 8 and at the same time the ID number having been registered in the IC card is recorded into the decoder device 11. Then, by registering the permit number of renewal which limits the number of renewal to the IC card 8 and decreasing the permit number of renewal for every renewal, unlimited renewal can be prevented. Also the information supplier 1 can grasp the situation by seeing the IC card 8. |
