Takeshi OKAMOTO


400Gbit/s/ch Field Demonstration of Modulation Format Adaptation Based on Pilot-Aided OSNR Estimation Using Real-Time DSP
Seiji OKAMOTO Kazushige YONENAGA Kengo HORIKOSHI Mitsuteru YOSHIDA Yutaka MIYAMOTO Masahito TOMIZAWA Takeshi OKAMOTO Hidemi NOGUCHI Jun-ichi ABE Junichiro MATSUI Hisao NAKASHIMA Yuichi AKIYAMA Takeshi HOSHIDA Hiroshi ONAKA Kenya SUGIHARA Soichiro KAMETANI Kazuo KUBO Takashi SUGIHARA 
Publication:   
Publication Date: 2017/10/01
Vol. E100-B  No. 10  pp. 1726-1733
Type of Manuscript:  INVITED PAPER (Joint Special Section on Opto-electronics and Communications for Future Optical Network)
Category: 
Keyword: 
adaptive modulationfield trialreal-time DSP400Gbit/s
 Summary | Full Text:PDF(4.3MB)

Sender Authenticated Key Agreements without Random Oracles
Chifumi SATO Takeshi OKAMOTO Eiji OKAMOTO 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2009/08/01
Vol. E92-A  No. 8  pp. 1787-1794
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: Theory
Keyword: 
authenticated key agreementsone-way functionsdecision co-bilinear Diffie-Hellman problemsstandard models
 Summary | Full Text:PDF(232.5KB)

An ID-SP-M4M Scheme and Its Security Analysis
Lihua WANG Eiji OKAMOTO Ying MIAO Takeshi OKAMOTO Hiroshi DOI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2007/01/01
Vol. E90-A  No. 1  pp. 91-100
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Signatures
Keyword: 
series-parallel multisignaturepairingID-basedBDH assumption
 Summary | Full Text:PDF(316.9KB)

Authorization-Limited Transformation-Free Proxy Cryptosystems and Their Security Analyses
Lihua WANG Zhenfu CAO Takeshi OKAMOTO Ying MIAO Eiji OKAMOTO 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2006/01/01
Vol. E89-A  No. 1  pp. 106-114
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Protocol
Keyword: 
proxy cryptosystempairingauthorization-limitedtransformation-freeBDH assumption
 Summary | Full Text:PDF(424.3KB)

A Fast Signature Scheme with New On-line Computation
Takeshi OKAMOTO Hirofumi KATSUNO Eiji OKAMOTO 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2004/05/01
Vol. E87-A  No. 5  pp. 1154-1161
Type of Manuscript:  Special Section LETTER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
digital signatureon-line computationrandom oracle modelprovable security
 Summary | Full Text:PDF(187KB)

On the Security of the Okamoto-Tanaka ID-Based Key Exchange Scheme against Active Attacks
Seungjoo KIM Masahiro MAMBO Takeshi OKAMOTO Hiroki SHIZUYA Mitsuru TADA Dongho WON 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2001/01/01
Vol. E84-A  No. 1  pp. 231-238
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
Okamoto-Tanaka key exchange schemeID-based schemeactive attackknown-key attackforward secrecy
 Summary | Full Text:PDF(288.5KB)

A Distributed Approach against Computer Viruses Inspired by the Immune System
Takeshi OKAMOTO Yoshiteru ISHIDA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2000/05/25
Vol. E83-B  No. 5  pp. 908-915
Type of Manuscript:  Special Section PAPER (IEICE/IEEE Joint Special Issue on Autonomous Decentralized Systems)
Category: Communication and Computer Architecture/Assurance Systems
Keyword: 
computer virusimmune systemagentself-referencecell division
 Summary | Full Text:PDF(505.5KB)