A decryption processing unit decrypts encrypted content data using a
license key Kc. When an elapsed time after reception of the license key
(Kc) does not exceed a hold time at a time of the license key (Kc)
included in reproduction control information (ACp), reproduction of
encrypted content data continues. When the elapsed time exceeds the hold
time at a time, the license key (Kc) is discarded, and a reproduction
control unit again obtains a license key (Kc) from a memory card.
Discarding and reobtaining license key (Kc) continues until an allowable
output count of license key (Kc) from the memory card becomes zero. As a
result, a reproduction time of encrypted content data can be controlled
safely.