| 摘要 |
PROBLEM TO BE SOLVED: To provide a data terminal device capable of protecting contents data distributed via a digital communication network. SOLUTION: A cellular phone 100 is equipped with a contents reproducing circuit 1550 for decrypting and reproducing encrypted contents data. The contents reproducing circuit 1550 includes a KPpc holding unit 1507 for holding an individual public encryption key KPpc2 of unique type for itself, a Kpc holding unit 1512 for holding an individual private decryption key Kpc2 by which data encrypted by the individual public encryption key KPpc2 is decrypted, and a session key generating unit 1508 for generating a session key Ks3 which specifies communication with a memory card 110. During reproduction, a controller 1106 receives a license key encrypted sequentially by the individual public encryption key KPpc2 and the session key Ks3, and gives it to the contents reproducing circuit 1550. |
