There is provided a license devolution system for devolving the right of using
as to contents. The license devolution system makes it possible to copy or distribute
contents while contributing to a protection of the copyright for the contents.
Contents is encrypted with a first key. The first key and use information are encrypted
with a second key consisting of a media ID for identifying a first storage medium
in which the first key and the use information are stored. In order to devolve
the right of using as to the contents, the contents is transferred to a second
storage medium of a destination of devolution in the form of encryption. The first
key and the use information are decoded with the media ID of the first storage
medium, and further encrypted with the media ID of the second storage medium of
the destination of devolution into storage in the second storage medium of the
destination of devolution.