Plural program information and a BCA (Burst Cutting Area) number of the optical
disc 100 is previously recorded in the optical disc 100. A drive
ID is stored in the nonvolatile memory 104a of the reproduction apparatus
104. A user of the reproduction apparatus 104 notifies the BCA number,
the drive ID, and a number of preferred program information to the software house
(software supplier) 110 on the condition that the user pays for the reproduction
of the preferred program information recorded in the optical disc 100. The
software house 110 notifies a cipher key to the reproduction apparatus 104
or the user. A title key is calculated in the reproduction apparatus 104
in accordance with the BCA number, the drive ID, and the cipher key. The preferred
information recorded in the optical disc 100 is permitted to be reproduced
by using the title key.