A recording/reproducing apparatus includes: a first storage section for
storing data structure information which includes encrypted data; a
special information holding section for holding special information
associated with the data structure information; and a controller for
controlling the first storage section and the special information holding
section. The data structure information is associated with the special
information such that the special information is updated in response to
an update of the data structure information, or such that the data
structure information is updated in response to an update of the special
information. The controller controls movement of the encrypted data from
the first storage section to a second storage section, and the controller
updates the special information such that a mismatch occurs between the
special information obtained before the movement of the encrypted data
and the special information obtained after the movement of the encrypted
data.