Issued Patents 2002
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6463155 | Broadcast reception device and contract management device using common master key in conditional access broadcast system | Koichiro Akiyama, Toru Kambayashi, Shuichi Tsujimoto | 2002-10-08 |
| 6438692 | Copy protection apparatus and information recording medium used in this copy protection apparatus | Taku Kato, Takehisa Kato, Kenjiro Endoh, Hisashi Yamada | 2002-08-20 |
| 6347145 | Method and apparatus of enciphering and deciphering data using keys enciphered and deciphered with other keys | Takehisa Kato, Hiroaki Unno, Tadashi Kojima, Koichi Hirayama | 2002-02-12 |