Utilizing and delivering contents

A method for delivering contents;

• comprising the steps of:
• in response to a download request of the contents, generating authentication data using a date when said request is accepted, wherein said authentication data includes a start date of use specifying the start date of use for the contents and an end date of use specifying an expiration date of the contents;
• and
• sending the contents, a regeneration program for said contents, and said authentication data, wherein the regeneration program comprising the functions of:
• acquiring a current date from a system timer;
• determining first whether the last date of use of said contents is prior to said current date;
• determining secondly whether said current date is prior to said end date of use;
• regenerating said contents if determinations made by both of said determination functions result in true;
• and
• updating said last date of use with a date when the regeneration of said contents is finished.

A system for delivering contents;

• said system in response to a download request of the contents, comprising:
• means for generating authentication data using a date when said request is accepted, wherein said authentication data includes a start date of use specifying the start date of use for the contents and an end date of use specifying an expiration date of the contents;
• and
• means for sending said contents, a regeneration program for said contents, and said authentication data, wherein said regeneration program comprises functions of:
• acquiring a current date from a system timer;
• determining first whether the last date of use of said contents is prior to said current date;
• determining secondly whether said current date is prior to said end date of use;
• regenerating said contents if determinations made by both of said determining functions result in true;
• and
• updating said last date of use with a date when the regeneration of said contents is finished.

A program executable by a computer to perform a method for utilizing contents;

• the program comprising the functions of:
• acquiring authentication data including a start date of use specifying the start date of use for the contents, an end date of use specifying an expiration date of the contents, and a last date of use specifying when the contents were last used;
• acquiring a current date from a system timer;
• determining first whether said last date of use is prior to said current date;
• determining secondly whether said current date is prior to said end date of use;
• regenerating said contents if determinations made by both of said determination functions result in true;
• and updating said last date of use with a date when the regeneration of said contents is finished.