| 摘要 |
PROBLEM TO BE SOLVED: To provide a predetermined service, on a mobile unit side, only for a content file created by using a rightful content production tool, in a multimedia content file provision service for a mobile unit (for instance, a cellular phone). SOLUTION: The mobile unit side includes: a means (S12) to authenticate a public key certificate in a content file acquired by using a root certificate held in the inside in advance; a means (S13) to decode authentication data encrypted by a secret key by using a public key embedded in a header part to obtain a first hash value; means (S14, 15) to obtain a second hash value by extracting partial data of a plurality of parts identical to those of previously reported parts; a means (S16) to compare the first hash value with the second hash value; and means (S17, 18) to provide a predetermined service when they coincide with each other, and to prevent the service from being provided when they do not coincide with each other. COPYRIGHT: (C)2010,JPO&INPIT |
