Hitherto, content such as image information and audio information has been provided to individual users mainly through television broadcasting and radio broadcasting. However, the Internet has been widely used nowadays, and content has been provided through the Internet. For example, sites that show content such as images created or recorded by individual users to other users have been operated. On such sites, content that has been freely uploaded by individual users can be viewed by many other users at no cost.
However, content uploaded by individual users to the above-described sites includes content that has been provided without the permission of the copyright holder. Thus, the profits of the copyright holder may be adversely affected.
Therefore, TVanytime (registered trademark), which is an industry organization that promotes standardization of digital television broadcasting technology, has proposed to add a CRID (Content Reference Identification), which is a unique ID, to every broadcast program and every content on the Internet (e.g., see Non-Patent Document 1). By identifying content with the CRID, the content's copyright can be managed.
[Non-Patent Document 1] “Sutoregi Zentei No Jisedai TV ‘TV Anytime’ No Zenyou Content Wo ID-ka Housou, Internet Wo Kensaku (The Full Scope of ‘TV Anytime’: the Next Generation TV Assuming Storage--Assigning ID to Content and Searching Broadcasts and Internet)”, “Nikkei Electronics Apr. 23, 2001, no. 794 (Apr. 23, 2001), Junichi KISHIGAMI, Nikkei BP, Inc.