Issued Patents All Time
Showing 1–24 of 24 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7433474 | Method and apparatus of enciphering and deciphering data using keys enciphered and deciphered with other keys | Takehisa Kato, Hiroaki Unno, Tadashi Kojima, Koichi Hirayama | 2008-10-07 |
| 7233667 | Record medium, record medium manufacturing device, computer readable record medium on which program is recorded, and data presentation device | Taku Katoh, Koichi Hirayama, Hisashi Yamada | 2007-06-19 |
| 7096357 | Cryptographic communication terminal, cryptographic communication center apparatus, cryptographic communication system, and storage medium | Kouya Tochikubo | 2006-08-22 |
| 6888943 | Multimedia adaptive scrambling system (MASS) | Katherine S. Lam, Kamran Moallemi, Chong U. Lee, Taku Katoh | 2005-05-03 |
| 6751321 | Digital data reproduction device | Takehisa Kato, Kenji Shimoda | 2004-06-15 |
| 6650752 | Broadcast reception device and contract management device using common master key in conditional access broadcast system | Koichiro Akiyama, Toru Kambayashi, Shuichi Tsujimoto | 2003-11-18 |
| 6650754 | Broadcast reception device and contract management device using common master key in conditional access broadcast system | Koichiro Akiyama, Toru Kambayashi, Shuichi Tsujimoto | 2003-11-18 |
| 6556679 | Copy-guard system and information recording medium used in the same system | Takehisa Kato, Taku Katoh, Kenjiro Endoh, Hisashi Yamada | 2003-04-29 |
| 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 |
| 6301663 | Copy protection apparatus and information recording medium used in this copy protection apparatus | Taku Kato, Takehisa Kato, Kenjiro Endoh, Hisashi Yamada | 2001-10-09 |
| 6160890 | Secret key transfer method which is highly secure and can restrict the damage caused when the secret key is leaked or decoded | Makoto Tatebayashi, Motoji Ohmori, Takehisa Kato, Koichi Hirayama | 2000-12-12 |
| 6151394 | Encrypted communication system that limits the damage caused when a secret key has been leaked | Makoto Tatebayashi, Yoshihisa Fukushima, Takehisa Kato, Koichi Hirayama | 2000-11-21 |
| 6085323 | Information processing system having function of securely protecting confidential information | Hideo Shimizu, Satomi Hori, Toshiaki Saisho | 2000-07-04 |
| 6009174 | Secret key transfer method which is highly secure and can restrict the damage caused when the secret key is leaked or decoded | Makoto Tatebayashi, Motoji Ohmori, Takehisa Kato, Koichi Hirayama | 1999-12-28 |
| 5984174 | Method of printing bar codes on pieces to deliver, and method and system for encoding and decoding bar codes | Takehisa Kato | 1999-11-16 |
| 5818031 | Bar code encoding system using four-state codes | — | 1998-10-06 |
| 5819103 | Information recording/reproducing apparatus and method | Toshimitsu Kaneko, Shunichi Numazaki | 1998-10-06 |
| 5253120 | Recording/reproducing apparatus for more efficient recording and reproduction of audio and video signals | — | 1993-10-12 |
| 5170388 | Image/audio information recording/reproduction apparatus with built-in semiconductor memory | — | 1992-12-08 |
| 5101394 | Data reproducing apparatus | — | 1992-03-31 |
| 5042037 | Digital data modulation circuit having a DC component suppression function | — | 1991-08-20 |
| 4553131 | Method and apparatus for encoding a binary data stream into a binary code stream | — | 1985-11-12 |