a) Field of the Invention
The present invention relates to a restriction canceling apparatus suitable for distribution of contents such as application programs, image files and MIDI files.
b) Description of the Related Art
Various contents such as application programs, image files, video files and MIDI files are sold via the Internet. A server used by a content provider stores content files, and a client can download a desired content file. If a content provider intends to provide a plurality kind of contents, it is necessary to prepare content files same in number as the number of contents.
With conventional distribution techniques, management by a content provider is cumbersome. For example, contents are required to be arranged by each price or relevant contents are required to be distributed one content at a time.
Some contents are classified into a plurality of grades or have options. In such a case, some clients first buy low price grade contents or basic contents, and some time later, buy upper grade contents or options. However, the client is required to download a large amount of data each time the client buys upper grade contents or options, so that a download work and communication traffics increase.