Kazuto OGAWA


Attribute-Based Encryption for Range Attributes
Nuttapong ATTRAPADUNG Goichiro HANAOKA Kazuto OGAWA Go OHTAKE Hajime WATANABE Shota YAMADA 
Publication:   
Publication Date: 2018/09/01
Vol. E101-A  No. 9  pp. 1440-1455
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
attribute-based encryptionrange attributegeneric construction
 Summary | Full Text:PDF(2MB)

FOREWORD
Kazuto OGAWA 
Publication:   
Publication Date: 2018/01/01
Vol. E101-A  No. 1  pp. 1-2
Type of Manuscript:  FOREWORD
Category: 
Keyword: 
 Summary | Full Text:PDF(287.3KB)

Partially Wildcarded Ciphertext-Policy Attribute-Based Encryption and Its Performance Evaluation
Go OHTAKE Kazuto OGAWA Goichiro HANAOKA Shota YAMADA Kohei KASAMATSU Takashi YAMAKAWA Hideki IMAI 
Publication:   
Publication Date: 2017/09/01
Vol. E100-A  No. 9  pp. 1846-1856
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
attribute-based encryptionciphertext policywildcard
 Summary | Full Text:PDF(1.8MB)

How to Make Traitor Tracing Schemes Secure against a Content Comparison Attack in Actual Services
Kazuto OGAWA Goichiro HANAOKA Hideki IMAI 
Publication:   
Publication Date: 2017/01/01
Vol. E100-A  No. 1  pp. 34-49
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
traitor tracingcollusion attackcontent comparisonencodingwatermarkingc-secure code
 Summary | Full Text:PDF(857.6KB)

Application Authentication System with Efficiently Updatable Signature
Kazuto OGAWA Go OHTAKE 
Publication:   IEICE TRANSACTIONS on Information and Systems
Publication Date: 2016/01/01
Vol. E99-D  No. 1  pp. 69-82
Type of Manuscript:  Special Section PAPER (Special Section on Enriched Multimedia---Creation of a New Society through Value-added Multimedia Content---)
Category: 
Keyword: 
hybrid services through broadcasting and communications networksapplication authenticationID-based signaturekey-insulated signature
 Summary | Full Text:PDF(913.9KB)

Weakened Anonymity of Group Signature and Its Application to Subscription Services
Kazuto OGAWA Go OHTAKE Arisa FUJII Goichiro HANAOKA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2014/06/01
Vol. E97-A  No. 6  pp. 1240-1258
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
subscription serviceanonymitylinkabilityunlinkabilitygroup signature
 Summary | Full Text:PDF(1.2MB)

Secure Broadcast System with Simultaneous Individual Messaging
Arisa FUJII Go OHTAKE Goichiro HANAOKA Nuttapong ATTRAPADUNG Hajime WATANABE Kazuto OGAWA Hideki IMAI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2011/06/01
Vol. E94-A  No. 6  pp. 1328-1337
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
digital broadcastingcopyright protectionConditional Access System (CAS)broadcast encryption
 Summary | Full Text:PDF(729.8KB)

Efficient Provider Authentication for Bidirectional Broadcasting Service
Go OHTAKE Goichiro HANAOKA Kazuto OGAWA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2010/06/01
Vol. E93-A  No. 6  pp. 1039-1051
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: Cryptography and Information Security
Keyword: 
bidirectional broadcasting serviceprovider authenticationpersonal information protectionkey leakagestrong key-insulated signature
 Summary | Full Text:PDF(792.7KB)

A Trade-off Traitor Tracing Scheme
Go OHTAKE Kazuto OGAWA Goichiro HANAOKA Hideki IMAI 
Publication:   IEICE TRANSACTIONS on Information and Systems
Publication Date: 2009/05/01
Vol. E92-D  No. 5  pp. 859-875
Type of Manuscript:  Special Section PAPER (Special Section on Information and Communication System Security)
Category: Contents Protection
Keyword: 
dynamic traitor tracingwatermarkingdigital rights managementcontent distribution
 Summary | Full Text:PDF(786.3KB)

An Efficient 2-Secure and Short Random Fingerprint Code and Its Security Evaluation
Koji NUIDA Satoshi FUJITSU Manabu HAGIWARA Hideki IMAI Takashi KITAGAWA Kazuto OGAWA Hajime WATANABE 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2009/01/01
Vol. E92-A  No. 1  pp. 197-206
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Application
Keyword: 
fingerprintc-secure codecollusion attacksecurity analysiswatermarkDRM
 Summary | Full Text:PDF(528.7KB)

Extension of Broadcasting Service by Using Electronic Tokens
Kazuto OGAWA Goichiro HANAOKA Hideki IMAI 
Publication:   IEICE TRANSACTIONS on Information and Systems
Publication Date: 2007/11/01
Vol. E90-D  No. 11  pp. 1741-1750
Type of Manuscript:  PAPER
Category: Contents Technology and Web Information Systems
Keyword: 
content distributiontokenanonymitygroup signatureprivacy preservation
 Summary | Full Text:PDF(470.5KB)

Traitor Tracing Scheme Secure against Adaptive Key Exposure and its Application to Anywhere TV Service
Kazuto OGAWA Goichiro HANAOKA Hideki IMAI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2007/05/01
Vol. E90-A  No. 5  pp. 1000-1011
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
traitor tracingkey exposurekey updatetwo variable-polynomial
 Summary | Full Text:PDF(547.8KB)

Managing Encryption and Key Publication Independently in Digital Rights Management Systems
Goichiro HANAOKA Kazuto OGAWA Itsuro MUROTA Go OHTAKE Keigo MAJIMA Seiichi GOHSHI Kimiyuki OYAMADA Seiichi NAMBA Hideki IMAI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2004/01/01
Vol. E87-A  No. 1  pp. 160-172
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Applications
Keyword: 
digital rights management systemscopyright protectionsemantic securityadaptive attacks
 Summary | Full Text:PDF(407.4KB)