Issued Patents All Time
Showing 1–25 of 30 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 11909873 | Decryption device, cryptographic system, and decryption method | Katsuyuki Takashima, Pratish Datta | 2024-02-20 |
| 11888968 | Signature device, verification device, signature method, verification method, and computer readable medium | Katsuyuki Takashima, Pratish Datta | 2024-01-30 |
| 9722783 | Cryptographic system | Katsuyuki Takashima | 2017-08-01 |
| 9413531 | Cryptographic system, cryptographic method, cryptographic program, and decryption device | Katsuyuki Takashima | 2016-08-09 |
| 9407438 | Cryptographic system, cryptographic method, and cryptographic program | Katsuyuki Takashima | 2016-08-02 |
| 9385867 | Cryptographic processing system, key generation device, encryption device, decryption device, key delegation device, cryptographic processing method, and cryptographic processing program | Katsuyuki Takashima | 2016-07-05 |
| 9203622 | Cryptographic processing system, cryptographic processing method, cryptograhpic processing program, and key generation device | Katsuyuki Takashima | 2015-12-01 |
| 9183411 | Cryptographic processing system, key generation device, encryption device, decryption device, cryptographic processing method, and cryptographic processing program utilizing attribute information for generation of a key for decryption or encryption | Katsuyuki Takashima | 2015-11-10 |
| 9106408 | Signature processing system, key generation device, signature device, verification device, signature processing method, and signature processing program | Katsuyuki Takashima | 2015-08-11 |
| 8938623 | Cryptographic processing system, key generation device, encryption device, decryption device, cryptographic processing method, and cryptographic processing program | Katsuyuki Takashima | 2015-01-20 |
| 8929542 | Cryptographic processing system, key generation device, key delegation device, encryption device, decryption device, cryptographic processing method, and cryptographic processing program | Katsuyuki Takashima | 2015-01-06 |
| 8913742 | Cryptographic processing system, key generation device, encryption device, decryption device, signature processing system, signature device, and verification device | Katsuyuki Takashima | 2014-12-16 |
| 8577030 | Cryptographic processing system, key generation device, key delegation device, encryption device, decryption device, cryptographic processing method, and cryptographic processing program | Katsuyuki Takashima | 2013-11-05 |
| 8559638 | Cryptographic processing system | Katsuyuki Takashima | 2013-10-15 |
| 8458478 | Signature generating apparatus, signature verifying apparatus, and methods and programs therefor | Koutarou Suzuki, Masayuki Abe, Atsushi Fujioka, Go Yamamoto | 2013-06-04 |
| 7222108 | Electronic cash implementing method and equipment using user signature and recording medium recorded thereon a program for the method | Hidemi Moribatake | 2007-05-22 |
| 6539364 | Electronic cash implementing method and equipment using user signature and recording medium recorded thereon a program for the method | Hidemi Moribatake | 2003-03-25 |
| 6480605 | Encryption and decryption devices for public-key cryptosystems and recording medium with their processing programs recorded thereon | Shigenori Uchiyama | 2002-11-12 |
| 6212637 | Method and apparatus for en-bloc verification of plural digital signatures and recording medium with the method recorded thereon | Kazuo Ohta | 2001-04-03 |
| 6072876 | Method and system for depositing private key used in RSA cryptosystem | Masanori Obata, Hiroyuki Sugiyama, Moribumi Okukawa | 2000-06-06 |
| 6003765 | Electronic cash implementing method with a surveillance institution, and user apparatus and surveillance institution apparatus for implementing the same | — | 1999-12-21 |
| 5926548 | Method and apparatus for implementing hierarchical electronic cash | — | 1999-07-20 |
| 5901229 | Electronic cash implementing method using a trustee | Eiichiro Fujisaki, Kazuo Ohta | 1999-05-04 |
| 5502765 | Method and apparatus for settlement of accounts by IC cards | Ginya Ishiguro, Toshiyasu Muta, Kazutaka Sakita, Shoji Miyaguchi, Atsushi Fujioka | 1996-03-26 |
| 5446796 | Method and apparatus for settlement of accounts by IC cards | Ginya Ishiguro, Toshiyasu Muta, Kazutaka Sakita, Shoji Miyaguchi, Atsushi Fujioka | 1995-08-29 |