Issued Patents 2002
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6438692 | Copy protection apparatus and information recording medium used in this copy protection apparatus | Taku Kato, Kenjiro Endoh, Hisashi Yamada, Naoki Endoh | 2002-08-20 |
| 6381331 | Information sending system and method for sending encrypted information | — | 2002-04-30 |
| 6347145 | Method and apparatus of enciphering and deciphering data using keys enciphered and deciphered with other keys | Naoki Endoh, Hiroaki Unno, Tadashi Kojima, Koichi Hirayama | 2002-02-12 |
| 6343281 | Device and method for preventing fraudulent copies of data containing encrypted copy-management information and recording medium | — | 2002-01-29 |