ZUGRIFFSSTEUERUNG AUF GESICHERTEN DIGITALEN INHALT

摘要

The present invention provides for deterring and/or preventing an illegal use of contents by users when an expiration date is established for the use of the contents. Contents or contents execution programs have information indicative of an expiration date. In an example, expiration date information is embedded into external files, contents or contents execution programs. The expiration date information could be a start, end or last date of use, which is used as authentication data to conduct authentication when making use of the contents. An example embodiment has two requirements satisfied when using the contents in order to execute the execution program, including (1) the current date acquired from the system timer is between the start date of use and the end date of use (expiration date); and (2) the current date is posterior to the last date of use (last date of access).