A cellular phone (100) stores encrypted content data and encrypted license
key distributed thereto in a memory card (110). The cellular phone (100)
and the memory card (110) collectively perform a part of mutual authentication
processing upon power-on. The encrypted license key (Kc) read from the memory card
(110) is decrypted by a first decryption processing portion (1510)
with a session key (Ks4), and is further decrypted by a second decryption
processing portion (1514) with a system symmetric key (Kcom) for extraction.
A third encryption processing portion (1516) decrypts the encrypted content
data read from memory card (110) with the license key (Kc) to reproduce
content data (Data).
