A cellular phone has distributed encrypted content data and an encrypted
content key stored in a memory. The encrypted content key data read out
from the memory is decrypted by a decryption processing unit using key
data Kp stored in a Kp hold unit, and then applied to a audio
reproduction module. A decryption processing unit decrypts encrypted
content data read out from the memory using a content key Kc extracted by
the decryption processing unit to reproduce content data Dc.