Inventor
OKAMOTO TATSUAKI
JP30 patents
⚠️ This page may combine multiple inventors who share the name “OKAMOTO TATSUAKI”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
NIPPON TELEGRAPH & TELEPHONE
15 patentsUS5926548AJul 20, 1999
Method and apparatus for implementing hierarchical electronic cash
NIPPON TELEGRAPH & TELEPHONE215 citations99
US5224162AJun 29, 1993
Electronic cash system
NIPPON TELEGRAPH & TELEPHONE194 citations99
US4977595ADec 11, 1990
Method and apparatus for implementing electronic cash
NIPPON TELEGRAPH & TELEPHONE433 citations99
US5901229AMay 4, 1999
Electronic cash implementing method using a trustee
NIPPON TELEGRAPH & TELEPHONE163 citations98
US4969189ANov 6, 1990
Authentication system and apparatus therefor
NIPPON TELEGRAPH & TELEPHONE127 citations98
US5502765AMar 26, 1996
Method and apparatus for settlement of accounts by IC cards
NIPPON TELEGRAPH & TELEPHONE129 citations97
US5396558AMar 7, 1995
Method and apparatus for settlement of accounts by IC cards
NIPPON TELEGRAPH & TELEPHONE235 citations97
US6212637B1Apr 3, 2001
Method and apparatus for en-bloc verification of plural digital signatures and recording medium with the method recorded thereon
NIPPON TELEGRAPH & TELEPHONE59 citations96
US6003765ADec 21, 1999
Electronic cash implementing method with a surveillance institution, and user apparatus and surveillance institution apparatus for implementing the same
NIPPON TELEGRAPH & TELEPHONE64 citations96
US6072876AJun 6, 2000
Method and system for depositing private key used in RSA cryptosystem
NIPPON TELEGRAPH & TELEPHONE127 citations95
US4625076ANov 25, 1986
Signed document transmission system
NIPPON TELEGRAPH & TELEPHONE149 citations95
US6539364B2Mar 25, 2003
Electronic cash implementing method and equipment using user signature and recording medium recorded thereon a program for the method
NIPPON TELEGRAPH & TELEPHONE69 citations94
US5446796AAug 29, 1995
Method and apparatus for settlement of accounts by IC cards
NIPPON TELEGRAPH & TELEPHONE62 citations94
US6480605B1Nov 12, 2002
Encryption and decryption devices for public-key cryptosystems and recording medium with their processing programs recorded thereon
NIPPON TELEGRAPH & TELEPHONE72 citations91
US7222108B2May 22, 2007
Electronic cash implementing method and equipment using user signature and recording medium recorded thereon a program for the method
NIPPON TELEGRAPH & TELEPHONE13 citations82
TAKASHIMA KATSUYUKI
10 patentsUS8938623B2Jan 20, 2015
Cryptographic processing system, key generation device, encryption device, decryption device, cryptographic processing method, and cryptographic processing program
TAKASHIMA KATSUYUKI12 citations83
US8913742B2Dec 16, 2014
Cryptographic processing system, key generation device, encryption device, decryption device, signature processing system, signature device, and verification device
TAKASHIMA KATSUYUKI11 citations83
US8559638B2Oct 15, 2013
Cryptographic processing system
TAKASHIMA KATSUYUKI6 citations72
US9183411B2Nov 10, 2015
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
TAKASHIMA KATSUYUKI3 citations62
US8577030B2Nov 5, 2013
Cryptographic processing system, key generation device, key delegation device, encryption device, decryption device, cryptographic processing method, and cryptographic processing program
TAKASHIMA KATSUYUKI3 citations62
US9385867B2Jul 5, 2016
Cryptographic processing system, key generation device, encryption device, decryption device, key delegation device, cryptographic processing method, and cryptographic processing program
TAKASHIMA KATSUYUKI1 citations51
US9203622B2Dec 1, 2015
Cryptographic processing system, cryptographic processing method, cryptograhpic processing program, and key generation device
TAKASHIMA KATSUYUKI0 citations51
US9106408B2Aug 11, 2015
Signature processing system, key generation device, signature device, verification device, signature processing method, and signature processing program
TAKASHIMA KATSUYUKI2 citations51
US9407438B2Aug 2, 2016
Cryptographic system, cryptographic method, and cryptographic program
TAKASHIMA KATSUYUKI0 citations41
US8929542B2Jan 6, 2015
Cryptographic processing system, key generation device, key delegation device, encryption device, decryption device, cryptographic processing method, and cryptographic processing program
TAKASHIMA KATSUYUKI0 citations41
MITSUBISHI ELECTRIC CORP
4 patentsUS9413531B2Aug 9, 2016
Cryptographic system, cryptographic method, cryptographic program, and decryption device
MITSUBISHI ELECTRIC CORP4 citations73
US11909873B2Feb 20, 2024
Decryption device, cryptographic system, and decryption method
MITSUBISHI ELECTRIC CORP0 citations60
US11888968B2Jan 30, 2024
Signature device, verification device, signature method, verification method, and computer readable medium
MITSUBISHI ELECTRIC CORP0 citations60
US9722783B2Aug 1, 2017
Cryptographic system
MITSUBISHI ELECTRIC CORP0 citations41