| 摘要 |
PROBLEM TO BE SOLVED: To realize an efficient charging device, in the case that distribution of information is repeated by reducing charging traffic. SOLUTION: The charging device that imposes charging on the use of a decoding key corresponding to encrypted distribution information is provided with a count means that counts a validity of a minimum charge, a decoding bunch of keys 12 that are used in common with respect to a plurality of sets of the distribution information, a decoding circuit 11, that decodes the distribution information encrypted by using the decoding bunch of keys 12, and a counter 13 that counts number of times of use of the decoding bundle of keys 12 used by the decoding circuit 11, so as to permit the use of the decoding bundle of keys 12 by the minimum charge, when number of times of the use of the decoding bunch of keys 12 counted by the counter 13 is a prescribed number of times or smaller and when the validity is not expired. |
