In a content management method, content data is encrypted by a first key,
the first key is encrypted by plural types of second keys, the encrypted
first key is multiply encrypted by a third key, and the third key is
encrypted by a fourth key. These encrypted content data, a medium key
which is the first key encrypted by the second key and a move key which
is a first key multiply encoded by the second and third keys are recorded
in a recording medium, the third key encrypted by the fourth key is
recorded in a security region. This management method is managed by the
move key and the medium key.