[Japanese]/[English]
Updated on May 15, 2019
Kazuo Takaragi, Dr. Eng.
Biography
Kazuo Takaragi obtained BS and MS degree from Kyushu Institute of Technology and Tokyo Institute of Technology in 1975 and 1977 respectively. In 1977, he joined Hitachi, Ltd. At Systems Development Laboratory in Hitachi, he engaged in the research and development of system safety and security. In 1886, he obtained a doctor degree in safety engineering from the University of Tokyo. In 2004, he became the senior chief scientist at Yokohama Laboratory, Hitachi, Ltd. During the fall semester in 2007, he served as a visiting professor for Freiburg University in Germany. In 2012, he joined National Institute of Advanced Industrial Science and Technology (AIST), Japan as a deputy. director of Information Technology Research Institute (ITRI). Currently, he is a project manager of AIST. He also serves as a chief executive officer of HISAFE, LTD., and a guest professor of Chuo University. He wrote books such as "Practice, policy and law of blockchain," Chuokeizai-sha Inc., “Information Security,” Kindai Kagaku Sha Co., Ltd., "Firewall," Shokodo Co., Ltd., and "Internet Security," Ohmusha, Ltd., all in Japanese.
１．Books, publications, research reports
a.［English］
１）"Information Technology for a Safe and Secure Society in Japan", K. Takaragi, Advances in cyber security, Edited by D. Frank Hsu and Dorothy Marinucci, Fordham University Press, New York, pp. 207-216, 2013.
b.［Japanese］
１）" Current Situation and Issues of Cryptography and Quantum Computer," Kazuo Takaragi, Sven Wohlgemuth, Practice, policy and law of blockchain, Edited by Takashi Kubota, Chuokeizai-sha Inc, pp. 131−153, 2018.
２）"Information security －Cryptography · Authentication · Management －," Kazuo Takaragi, Kindai Kagaku Sha Co., Ltd., 2012.
３）"Firewall － About Internet technology －," Kazuo Takaragi、Minoru Koizumi，Masato Terada, Makoto Kayashima, Shokodo Co. Ltd, 1998.
４）"Internet Security － Foundation and countermeasure technology －," Ryoichi Sasaki, Kazuo Takaragi, Taketoshi Sakuraba, Masato Terada, Nariyasu Hamada, Ohmusha, Ltd., 1996.
２．Invited lecture
a.［English］
１）"IT Technology for Safe and Secure Society in Japan: Towards Cyber Physical Solution", K. Takaragi, International Conference on Cyber Security, 2010.8.
２）"Security Technology for Ubiquitous Information Society", K. Takaragi, Keynote Presentation at ETRICS, 2006.6.
b.［Japanese］
１）"Biometrics application situation for social infrastructure and its future subject," Kazuo Takaragi, BioX ITE-ME ITE-IST, IEICE, 2014.6.
２）"Road of IT Security Standard : From Cryptography to Cloud and M2M Security," Kazuo Takaragi、IT・ISEC・WBS, IEICE, 2013.3.
３）"Expectations from industry － Application to information security －," Kazuo Takaragi、Workshop, Think about future scenario of mathematics ― Toward the development of interdisciplinary research based on mathematics ― National Institute of Science and Technology Policy, Mathematical Society of Japan, 2005.6.
３． Review, Report
a.［English］
１）"IT Technology for Safe & Secure Society in the Asian Region", K. Takaragi, Keynote Speech 7th AFIT, 2009.2.
２）"Security Techniques for Next Generation －Cancelable bio and post quantum－", K. Takaragi, ZISC Information Security Colloquium, 2007.12.
b.［Japanese］
１）"Security of Olympic," Kazuo Takaragi、Information Processing Society of Japan、Vol.55, No.11,pp1196-1203, 2014.11.
２）"New Object for Information Security," Kazuo Takaragi, Japan Society of Security Management, Vol. 28, No. 1, pp.36-43, 2014.5.
３）"Road of IT security standard -- From cryptography to cloud and M2M security --," Kazuo Takaragi、Fundamentals Review, IEICE Engineering Sciences Society, pp. 51-59, Vol.7, No.1,2013.7.
４）"The Front Line of Next Generation Core Technology - Information Security Technology," Kazuo Takaragi, Hitachi Hyoron, Vol.87, No.5, pp.63-68, 2005.5
５）"Cryptographic technology for promoting e-society, － Progress of symmetric-key ciphers－ ," Kazuo Takaragi, Yukiyasu Tsunoo, Kenji Ohkuma, Mitsuru Matsui, Shiho Moriai, Takeshi Shimoyama、IPSJ Magazine、Vol.45, No.11, pp.1117-1122, 2004.11.
６）"System LSIs with cryptographic function and their applications," Kazuo Takaragi, Takao Arai, Kunihiko Nakada, Hideyuki Hara, Toru Yamada、Hitachi Hyoron、Vol. 81, No. 10, pp. 21-24, 1999.10.
７）"Information system and cryptographic technology," Kazuo Takaragi, The Journal of The Institute of Electrical Engineers of Japan、Vol, 112, No. 9, pp. 721-725,1992.9.
８）「Cryptography method and application」、Kazuo Takaragi、Tsutomu Nakamura、IPSJ Magazine、Vol. 1, No. 4, pp. 714-733,1991.6.
９）"Trend of authentication technology in transactions using computer networks," Ryoichi Sasaki, Kazuo Takaragi, IEICE Journal,Vol. 71, No. 12, pp. 1285-1287, 1988.12.
１０）"Security Techniques for Financial Systems," Kazuo Takaragi, Ryoichi Sasaki, Makoto Okumura, Hitachi Hyoron, Vol. 70, N0. 3, pp. 103-108, 1988.3.
１１）"Network security technology," Kazuo Takaragi, Ryoichi Sasaki, Yu Miura, Makoto Okumura, Hitachi Hyoron, Vol. 69, No. 9, pp. 67-74 1987.9.
１２）"Challenges remaining in RFID," Kazuo Takaragi, RSA Conference, 2004.6.
４．International Conference Committee Activity
１）The Fourth Resilience and IT-Risk in Social Infrastructures (RISI 2013〜2015) PC
２）25th IFIP International Information Security Conference Security & Privacy (SEC-2010) PC
３）IFIP World Computer Congress 2010 (WCC 2010) PC
４）The 4th International Workshop on Security (IWSEC2009) General Co-Chair
５．Award
１）" CYBER 2018 Best Paper Award," Katsuyuki Umezawa, Yusuke Mishina, Sven Wohlgemuth, Kazuo Takaragi, 2018.
２）"Kanto Region Invention Awards - Incentive Awards Prize," Dai Watanabe, Soichi Furuya, Kazuo Takaragi, 2013.
３）"IPSJ Standardization Achievement Award," Kazuo Takaragi, 2011.
４）" METI Industrial Standardization Project Contributors Award, Kazuo Takaragi, 2010.
５）"IEICE Engineering Sciences Society - Achievement Award," Kazuo Takaragi, 2010.
６）" Top 100 inventors of Hitachi," Kazuo Takaragi, 2009.
７）"IPSJ Standardization Contribution Award," Kazuo Takaragi, 2007.
８）" IPSJ Best Paper Award," Ryoichi Sasaki, Kazuo Takaragi, 2002.
９）" Kanto Region Invention Awards - Incentive Awards Prize," Kazuo Takaragi, Ryoichi Sasaki, Fusao Nakagawa, 2002.
１０）"IEEJ Book of the Year Award," Ryoichi Sasaki, Kazuo Takaragi, Taketoshi Sakuraba, Masato Terada, Nariyasu Hamada, 1998.
６. Journal
a.［English, Peer reviewed, First author］
１）"An Ultra Small Individual Recognition Security Chip", Kazuo Takaragi, Mitsuo Usami, Ryo Imura, Rei Itsuki, Tsuneo Satoh, IEEE MICRO, November– December 2001, pp 43-49, 2001.12.
２）"System LSIs with Cryptographic Functions and Their Applications," Kazuo Takaragi, Kunihiko Nakada, Tooru Yamada, Takao Arai, Hideyuki Hara, Hitachi Review Vol. 48, No. 6, pp. 323-327, 1999
３）"On Differential Cryptanalysis", K. Takaragi, K. Hashimoto and T. Nakamura, IEICE Transactions, Vol. E 74, No. 8, pp. 2153-2159, 1991.8
４）"An Algorithm for Obtaining Simplified Prime Implicant Sets in Fault Tree and Event Tree Analysis", K. Takaragi, R. Sasaki and S. Shingai, IEEE Transaction on Reliability, Vol. R-32, No. 4, pp. 386-392, 1983.10.
５）"A Method for Rapid Markov Reliability Calculation", K. Takaragi, R. Sasaki, S. Shingai, IEEE Transaction on Reliability, Vol. R-34, No. 3, pp. 262-268, 1985.8
６）"An Probability Bound Estimation Method in Markov Reliability Analysis", K. Takaragi, R. Sasaki, S. Shingai, IEEE Transaction on Reliability, Vol. R-34, No. 3, pp. 257-261, 1985.8
７）"An Improved Moment-Matching Algorithm for Evaluating Top-Event Probability Bounds", K. Takaragi, R. Sasaki, S. Shingai,IEEE Transaction on Reliability, Vol. R-32, No. 4, pp. 386-392, 1983.10
b.［English, Peer reviewed, Co-author］
１）"Privacy-Enhancing Trust Infrastructure for Process Mining," Sven Wohlgemuth, Kazuo Takaragi, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Special Section on Cryptography and Information Security, E101.A.149, pp. 149-156, 2018.
２）"Verifying a signature architecture: a comparative case study," David Basin, Hironobu Kuruma, Kunihiko Miyazaki, Kazuo Takaragi, Burkhart Wolff, Formal Aspects of Computing (2007) 19: 63–91, 2007.
３）"A Formal Analysis of a Digital Signature Architecture," David Basin, Kunihiko Miyazaki, Kazuo Takaragi, Integrity and Internal Control in Information Systems VI pp 31-47, 2004.
４）"A New Keystream Generator MUGI," Dai Watanabe, Soichi Furuya, Hirotaka Yoshida, Kazuo Takaragi, Bart Preneel, IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences Vol.E87-A No.1 pp.37-45, 2003.1.
５）"Integrity-Aware Mode of Stream Cipher," Soichi Furuya, Dai Watanabe, Yoichi Seto, Kazuo Takaragi, IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences Vol.E85-A No.1 pp.58-65, 2002.1.
６）"A Threshold Digital Signature Scheme for a Smart Card Based System," Kunihiko Miyazaki, Kazuo Takaragi, IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences Vol.E84-A No.1 pp.205-213, 2001.1.
７）"A Threshold Digital Signature Scheme for a Smart Card Based System", K. Miyazaki, K. Takaragi, IEICE Transactions, Vol. E84-A, No. 1, pp. 205-213, 2001.1.
８）"A lightweight Encryption Method Suitable for Copyright Protection", M. Aikawa, K. Takaragi, S. Furuya and M. Sasamoto
, IEEE Transactions on Consumer Electronics, Vol. 44, No. 3, pp.902-910, 1998.8.
９）"Group Cipher System for Intranet Security", H. Ito, S. Susaki, M. Arai, M. Koizumi and K. Takaragi, IEICE Transactions, Vol. E81 A, No. 1, pp. 28-34, 1998.1.
c.［Japanese, Peer reviewed, First author］
１）"Hitachi's Cryptographic Technologies Focusing on Public Key Cryptosystem," Kazuo Takaragi, Mototsugu Nishioka, Hitachi Hyoron, Vol.88, No.07, 592-593, pp 74-79, 2006.7.
２）"Improvement of Rabin Type Public Key Cipher Algorithm for Authentication," Kazuo Takaragi, Ryoichi Sasaki, IEICE Journal D-I, Vol. J73-D-I, No. 3, pp. 350-357、1990.3.
３）"A Method of Risk Analysis for Computer Systems," Kazuo Takaragi, Ryoichi Sasaki, Yasuhiko
Nagai, Transaction on IEEJ, Vol. 108-C, No. 4, pp. 260-267, 1988.4.
４）"Authentication method for electronic contracts with IC card key management," Kazuo Takaragi, Takayoshi Shiraishi, Ryoichi Sasaki, Transaction on IEEJ, Vol 107-C, No. 1, pp. 46-53、1987.1.
５）"An Estimation Method of System Failure Frequency using Both Structure and Component Failure Data," Kazuo Takaragi, Ryoichi Sasaki, Sadanori Shingai, Kenji Tominaga, Transaction on Vol. 101-C, No. 8, pp.185-192.1981.8.
d.［Japanese, Peer reviewed, Co-author］
１）"A Formal Analysis of a Digital Signature System," Kunihiko MIYAZAKI, David BASIN, Hironobu KURUMA, Kazuo TAKARAGI, Satoru TEZUKA, JSSST, Computer Software, Vol.22, No.2, pp.74-84, 2005.4
２）"Analysis on History and Similarity of Seal and Electronic Sea," Ryoichi Sasaki, Kazuo Takaragi, IPSJ Journal, Vol. 42, No. 8, pp. 1968-1974、2001.8.
３）"RSA cryptographic key high-speed generation method," Yasuko Goto, Kazuo Takaragi, Ryoichi Sasaki, Transaction on IEICE, D-I, Vol. J72-D-I, No. 3, pp. 213-220、1989.3.
４）"Extensions of Mao & Wallingford's Method of Discrete Optimization," Ryoichi Sasaki, Sadanori Shingai, Kazuo Takaragi, Transaction on IEEJ, Vol. 100-C, No. 5, pp. 167-173、1980.5.
e.［Proceedings, Peer reviewed, First Author］
１）"A Practical and Fair Protocol for Signing Contract", K. Takaragi, T. Shiraishi and R. Sasaki, Proceedings of International Symposium in Information Theory, October 1986.
２）"A New Phased Mission Method and Its Application to FBR Shutdown Heat Removal Systems", K. Takaragi, R. Sasaki and S. Shingai, Proceedings of American Nuclear Society/European Nuclear Society Probabilistic Risk Analysis Topical Meeting, Vol. III, USA, pp. 1267-1276, 1981.9.
３）"A Technique for Analyzing Common Cause Failure in Subsystems", K. Takaragi, K. Tominaga, R. Sasaki and S. Shingai, Proceedings of American Nuclear Society Annual Meeting, pp. 298-299, 1979.6.
f.［Proceedings, Peer reviewed, Co-author］
１）"Competitive Compliance with Blockchain," Sven Wohlgemuth, Katsuyuki Umezawa, Yusuke Mishina and Kazuo Takaragi,PerCom 2019 Workshop SPT-IOT, 2019.3.
２）"Threat Analysis using Vulnerability Databases – Matching Attack Cases and Vulnerability Database by Topic Model Analysis –," Katsuyuki Umezawa, Yusuke Mishinay, Sven Wohlgemuthz and Kazuo Takaragi, CYBER 2018, 2018.11.
３）"A Method of Threat Analysis for Cyber-Physical System using Vulnerability Databases," Yusuke Mishina, Kazuo Takaragi, Katsuyuki Umezawa, the 18th Annual IEEE Symposium on Technologies for Homeland Security, 2018.10.
４）"Privacy with Secondary Use of Personal Information," Sven Wohlgemuth, Kazuo Takaragi, Isao Echizen, MKWI 2016.
５）"A Toolset for Usable Security with ICT Service Networks," Sven Wohlgemuth, Kazuo Takaragi, The 11th International Workshop on Security (IWSEC) 2016.
６）"Verification of a Signature Architecture with HOL-Z", David A. Basin, Hironobu Kuruma, Kazuo Takaragi, Burkhart Wolff, FM, pp. 269-285, 2005.
７）Dai Watanabe, Soichi Furuya, Hirotaka Yoshida, Kazuo Takaragi, Bart Preneel, "A New Keystream Generator MUGI," FSE 2002, pp.179-194, 2002.
８）"Generalized Powering Functions and Their Application to Digital Signatures", Hisayoshi Sato,
Tsuyoshi Takagi, Satoru Tezuka, Kazuo Takaragi, ASIACRYPT, pp. 434-451, 2003.
９）"Legally Authorized and Unauthorized Digital Evidence", Hiroshi Yoshiura, Kunihiko Miyazaki, Shinji Itoh, Kazuo Takaragi, Ryoichi Sasaki, Security Protocols Workshop, pp. 67-73, 2002.
１０）"A New Keystream Generator MUGI", Dai Watanabe, Soichi Furuya, Hirotaka Yoshida, Kazuo Takaragi, Bart Preneel, Proceedings of 9th International Workshop, FSE 2002, Leuven, Belgium, pp. 179-194, 2002.2.
１１）"Observations on Hierocrypt-3/L1 Key-scheduling Algorithms", Soichi Furuya, Hirotaka Yoshida, Dai Watanabe, Yoichi Seto, Kazuo Takaragi, 2nd NESSIE Workshop, Sep.2001.
１２）"A Multi-OS Approach to Trusted Computer Systems", Hiroshi Yoshiura, Kunihiko Miyazaki, Shinji Itoh, Kazuo Takaragi, Ryoichi Sasaki, Security Protocols Workshop, pp. 107-114, 2001.
１３）Hiroshi Yoshiura, Ryoichi Sasaki, Kazuo Takaragi, "Secure Fingerprinting Using Public-Key Cryptography," International Workshop on Security Protocols, pp 83-89, 1998.
１４）"Application of Probabilistic Safety Assessment Method to Evaluate the Effect of Test and Inspection on Nuclear Power Plant", K. Seki, K. Kumasaka, S. Itooka, K. Takaragi, SMiRT 11 Transactions Vol. G, Tokyo, Japan, pp. 381-386, 1991.8.
１）"Development of Computer Program to Assist Event Tree Analysis", R. Sasaki, K. Tominaga, K. Takaragi, S. Shingai, Proceedings of American Nuclear Society Annual Meeting, pp. 294-295, 1979.
７．Oral presentation, Poster presentation
a.［English］
None.
b.［Japanese］
１) "Technical issues and direction of research on virtual currency and block chain", Kazuo Takagi, International Trade Law Society and UNCITRAL co-sponsored symposium "UNCITRAL model method and virtual currency and block chain", 2019.3.
２) "The threat analysis method using vulnerability database-About utilization of topic model and reuse of past analysis results-", Katsuyuki Umezawa, Yusuke Sanshin, Sven Wohlgemuth, Kazuo Takaragi, Symposium on Cryptography and Information Security (SCIS 2019 ), 2019.1.
３) "Blockchain and IoT", Kazuo Takagi, Japan Measurement Instruments Association Conference, 2018.9.
４）"A Proposal of Threat Analyses using Vulnerability Databases," Katsuyuki Umezawa, Yusuke Mishina, Kenji Taguchi, Kazuo Takaragi, 2018 Symposium on Cryptography and Information Security、2018.1.
５）"Standards / guidelines and measures to promote security technology," Kazuo Takaragi, Hitoshi Ohsaki, Yusuke Mishina, Kenichi Handa, Hirofumi Sakane, AIST Information Technology and Human Factors Department Symposium - IoT and security - 2017 – Security of Connected Industry, 2017.12.
６）"Standards / guidelines and measures to promote security technology," Kazuo Takaragi, NEDO SIP Symposium on Securing Cyber Security in Critical Infrastructure, 2017.10.
７）"A consideration of a block chain that enables effective utilization of personal information," Kazuo Takaragi, Waseda University Academic Forum, the future that block chains open up, 2017.5.
８）"Conformity check method to encourage social implementation of research and development technology," Kazuo Takaragi, NEDO SIP Symposium on Securing Cyber Security in Critical Infrastructure, 2016.11.
９）"Design of certification system of cyber security in critical infrastructure etc," Kazuo Takaragi, Hitoshi Ohsaki, Hirofumi Sakane, Kenichi Handa, Kenji Taguchi, Daisuke Souma, AIST Information Technology and Human Factors Department Symposium - IoT and security - , 2016.3.
１０）"Biometrics application status and issues," Kazuo Takaragi, AIST Technical Exchange Salon, AIST Chugoku Center、2014.11.
１１）"Biometrics · Security", Takeshi Ohki, Rei Otsuka, Asahiko Yamada, Kazuo Takaragi, AIST 2nd Secure Systems Symposium, 2014.3.
１２）"Privacy-preserving database search technology", Goichiro Hanaoka, Kazuo Takaragi, AIST open lab, AISTech talk, 2013.10.
１３）"A Survey on Biometric Presentation Attack and It’s Security Evaluation
Method," Tetsushi Ohki, Akira Otsuka, Kazuo Takaragi, Proceedings of Biometrics Workshop, Biox2013-16, pp. 59-63, 2013.8
１４）"Information risk and management", Kazuo Takaragi, a forum for science of risk, Science Council of Japan、2012.9
１５）"Expectations from enterprise to mathematical association - from cryptographic development site", Kazuo Takaragi, Opening Ceremony of Institute of Mathematics for Industry, Kyushu University, 2011.4.
８．Industrial Property
a.［International （Priority date）］
１）"Unique code generating apparatus, method, program and recording medium," Masahiro Mimura, Kenta Takahashi, Kazuo Takaragi, Masakatsu Nishigaki, Yoichi Shibata, US7447339B2, 2003-10-17.
２）"Time stamp generating system," Kunihiko Miyazaki, Seiichi Susaki, Kazuo Takaragi, Hiroshi Yoshiura, Takeshi Matsuki, Hisashi Toyoshima,Mitsuru Iwamura, Tsutomu Matsumoto, Ryoichi Sasaki, US7200682B2, 2002-05-08.
３）"RFID tag, and RFID tag-related determining device and method, and management system and method," Masaru Ohki, Hideki Tokuyama, Rei Itsuki, Shojiro Asai, Kazuo Takaragi, Atsushi Tanaka, US7173515B2, 2002-03-07.
４）"Handling support method and handling support system," Hajime Morito, Yasuko Fukuzawa, Kazuo Takaragi, Shojiro Asai, US7138915B2, 2001-11-30.
５）"Trusted computer system," Kunihiko Miyazaki, Shinji Itoh, Hiroshi Yoshiura, Kazuo Takaragi, Masato Arai, Toshiaki Arai, Takeshi Matsuki, Hisashi Toyoshima, US7210043B2, 2001-04-24.
６）"Pseudorandom number generating apparatus or encryption or decryption apparatus using the same," Dai Watanabe, Soichi Furuya, Kazuo Takaragi, US7280659B2, 2001-01-23.
７）Kunihiko Miyazaki, Ryoichi Sasaki, Kazuo Takaragi, Seiichi Susaki, Hisanori Mishima, Takeshi Matsuki, Kunihito Takeuchi, Mitsuru Iwamura, Tsutomu Matsumoto, "Digital signature generating method and digital signature verifying method," US6816969B2, 2000-12-07.
８）"Database integration management method and apparatus and processing program, medium therefor," Chikashi Okamoto, Kazuo Takaragi, Yasuko Fukuzawa, Hideki Tokuyama, Mitsuo Usami, US6922686B2, 2000-11-02.
９）"Database integration management method and apparatus and processing program, medium therefor," Chikashi Okamoto, Kazuo Takaragi, Yasuko Fukuzawa, Hideki Tokuyama, Mitsuo Usami, US7333972B2, 2000-11-02.
１０）"Identification code management method and management system," Chikashi Okamoto, Kazuo Takaragi, Yasuko Fukuzawa, US6934842B2, 2000-07-06.
１１）"Identification code management method and management system," Chikashi Okamoto, Kazuo Takaragi, Yasuko Fukuzawa, US7178026B2, 2000-07-06.
１２）Soichi Furuya, Kazuo Takaragi, Hiroyuki Kurumatani, Masashi Takahashi, Kunihiko Miyazaki, Hisayoshi Sato, Dai Watanabe, "Method and apparatus for symmetric-key encryption," US7110545B2, 2000-03-09.
１３）Soichi Furuya, Kazuo Takaragi, Hiroyuki Kurumatani, Masashi Takahashi, Kunihiko Miyazaki, Hisayoshi Sato, Dai Watanabe, "Method and apparatus for symmetric-key decryption," US7359515B2, 2000-03-09.
１４）"Method and system for recovering the validity of cryptographically signed digital data," Kunihiko Miyazaki, Hiroshi Yoshiura, Seiichi Susaki, Ryoichi Sasaki, Kazuo Takaragi, Hisashi Toyoshima, Takeshi Matsuki, US7694126B2, 1999-10-22.
１５）"Method and system for recovering the validity of cryptographically signed digital data," Kunihiko Miyazaki, Hiroshi Yoshiura, Seiichi Susaki, Ryoichi Sasaki, Kazuo Takaragi, Hisashi Toyoshima, Takeshi Matsuki, US7134021B2, 1999-10-22.
１６）"Digital signing method," Kunihiko Miyazaki, Ryoichi Sasaki, Kazuo Takaragi, Seiichi Susaki, Toshiyuki Moritsu, Mizuhiro Sakai, Mitsuru Iwamura, Tsutomu Matsumoto, US7305558B1, 1999-10-22.
１７）"Digital signing method," Kunihiko Miyazaki, Ryoichi Sasaki, Kazuo Takaragi, Seiichi Susaki, Toshiyuki Moritsu, Mizuhiro Sakai, Mitsuru Iwamura, Tsutomu Matsumoto, US7770009B2, 1999-10-22.
１８）"Processing apparatus, program, or system of secret information," Kunihiko Miyazaki, Kazuo Takaragi, Yasuko Fukuzawa, US6873706B1, 1999-09-29.
１９）"Control system and method of controlling information written into storage media," Kazuo Takaragi, Chikashi Okamoto, US6592032B1, 1999-08-27.
２０）"Terminal for use in a system interfacing with storage media," Kazuo Takaragi, Chikashi Okamoto, US7089388B1, 1999-08-27.
２１）Kazuo Takaragi, Chikashi Okamoto, "Terminal for use in a system interfacing with storage media," US7330949B2, 1999-08-27.
２２）"Semiconductor devices," Mitsuo Usami, Kazutaka Tsuji,Takeshi Saito, Akira Sato, Kenji Sameshima, Kazuo Takaragi, Chizuko Yasunobu, US7061083B1, 1998-12-17.
２３）"Method of checking authenticity of sheet with built-in electronic circuit chip," Chikashi Okamoto, Kazuo Takaragi, Kazutaka Tsuji, Mitsuo Usami, Chizuko Yasunobu, Asahiko Isobe, Yasuhiro Tsunemi, Hiroyuki Yagi, US7007854B2, 1998-12-07.
２４）"Method of checking authenticity of sheet with built-in electronic circuit chip," Chikashi Okamoto, Kazuo Takaragi, Kazutaka Tsuji, Mitsuo Usami, Chizuko Yasunobu, Asahiko Isobe, Yasuhiro Tsunemi, Hiroyuki Yagi,US7309019B2, 1998-12-07.
２５）"Method for mounting electronic circuit chip," Chikashi Okamoto, Kazuo Takaragi, Kazutaka Tsuji, Mitsuo Usami, Chizuko Yasunobu, Asahiko Sobe, Yasuhiro Tsunemi, Hiroyuki Yagi, US6731509B1, 1998-11-30.
２６）"Method of checking authenticity of sheet with built-in electronic circuit chip," Chikashi Okamoto, Kazuo Takaragi, Kazutaka Tsuji, Mitsuo Usami, Chizuko Yasunobu, Asahiko Isobe, Yasuhiro Tsunemi, Hiroyuki Yagi, US6659353B1, 1998-07-12.
２７）"Encrypting conversion apparatus, decrypting conversion apparatus, cryptographic communication system, and electronic toll collection apparatus," Makoto Aikawa, Shigeru Hirahata, Kazuo Takaragi, Yoshimichi Kudo,US20030026430A1, 1998-05-29.
２８）"Encrypting conversion apparatus, decrypting conversion apparatus, cryptographic communication system, and electronic toll collection apparatus," Makoto Aikawa, Shigeru Hirahata, Kazuo Takaragi, Yoshimichi Kudo, US6683956B1, 1998-05-29.
２９）"Network system using a threshold secret sharing method," Seiji Miyazaki, Kazuo Takaragi, US6477254B1, 1998-02-13..
３０）"IC card equipped with elliptical curve encryption processing facility," Seiji Miyazaki, Kazuo Takaragi, US6466668B1, 1998-01-28
３１）"IC card equipped with elliptic curve encryption processing facility," Seiji Miyazaki, Kazuo Takaragi , US6714648B2, 1998-01-28.
３２）"Data encrypting/decrypting conversion methods and apparatuses and data communication system adopting the same," Makoto Aikawa, Kazuo Takaragi, Hiroyuki Koreeda, Manabu Sasamoto, Hiroo Okamoto, Takaharu Noguchi, Soichi Furuya, Shigeru Hirahata, US6606385B1, 1997-08-07.
３３）"Data encrypting/decrypting conversion methods and apparatuses and data communication system adopting the same," Makoto Aikawa， Kazuo Takaragi， Hiroyuki Koreeda， Manabu Sasamoto， Hiroo Okamoto， Takaharu Noguchi， Soichi Furuya， Shigeru Hirahata, US20010014154A1, 1997-08-07.
３４）"Digital data authentication method," Hiroshi Yoshiura， Kazuo Takaragi, Ryoichi Sasaki, Seiichi Susaki, Hisashi Toyoshima, Tsukasa Saito, US6499105B1, 1997-06-05.
３５）"Key recovery method and system," Kazuo Takaragi, Hiroyuki Kurumatani, US6236729B1, 1997-06-06.
３６）"Digital data authentication method," Hiroshi Yoshiura, Kazuo Takaragi, Ryoichi Sasaki, Seiichi Susaki, Hisashi Toyoshima, Tsukasa Saito, US6131162A, 1997-06-05.
３７）"Encrypted data recovery method using split storage key and system thereof," Eiji Okamoto, Masahiro Mambo, Seiichi Domyo, Hiroyoshi Tsuchiya, Tooru Kawai, Kazuo Takaragi, Naoya Torii, Takeshi Tanida, US6118874A, 1997-03-31.
３８）"Method and apparatus for generating hash value," Kazuo Takaragi, Hiroyuki Kurumatani, US6141421A , 1996-12-10.
３９）"Hash value generating method and device, data encryption method and device, data decryption method and device," Kazuo Takaragi, Hiroyuki Kurumatani, US6370247B1, 1996-12-10.
４０）"Hash value generating method and device, data encryption method and device, data decryption method and device," Kazuo Takaragi, Hiroyuki Kurumatani, US6122375A, 1996-12-10.
４１）"Digital signature generating/verifying method and system using public key encryption," Kazuo Takaragi, Hiroyuki Kurumatani, US6341349B1, 1996-10-31.
４２）"Method and device for managing computer network," Kazuo Takaragi, Seiichi Domyo, Hiroshi Yoshiura, US6311277B1, 1996-03-22.
４３）"Method and a device for managing a computer network," Kazuo Takaragi, Seiichi Domyo, Hiroshi Yoshiura, US7139759B2, 1996-03-22.
４４）"Method and apparatus for encrypting data," Hiroshi Yoshiura, Kazuo Takaragi, Mayuko Shimizu, US6157720A, 1996-02-28.
４５）"Method and apparatus for encrypting data," Hiroshi Yoshiura, Kazuo Takaragi, Mayuko Shimizu, US6504931B1, 1996-02-28.
４６）"Data compression/encryption method and system," Hiroshi Yoshiura, Kazuo Takaragi, Yusuke Hino, Yutaka Otsu, US6122378A, 1995-09-13.
４７）"Cryptographic communication system," Hikari Namba, Kazuo Takaragi, Satoshi Miyazaki, US5966448A, 1995-08-30.
４８）"Electronic document processing system and method of forming digital signature," Hiroshi Matsumoto, Kazuo Takaragi, Seiichi Susaki, Hiroyuki Maezawa, Shinobu Koizumi, US5465299A, 1992-12-03.
４９）"Group cipher communication method and group cipher communication system," Kazuo Takaragi, Seiichi Susaki, Hiroshi Matsumoto, Tsutomu Nakamura, US5309516A, 1990-12-07.
５０）"Encipher method and decipher method," Hiroshi Matsumoto, Kazuo Takaragi, Yasuko Fukuzawa, US5218638A, 1990-12-07.
５１）"Limited broadcast system," Hiroshi Matsumoto, Kazuo Takaragi, Yasuko Fukuzawa, US5351294A, 1990-12-07.
５２）"Cryptographic method and apparatus," Kazuo Takaragi, Tsutomu Nakamura, Masahiro Yamashita, Kazuo Hashimoto, Hiroshi Matsumoto, US5222139A, 1990-11-02.
５３）"File encryption method and file cryptographic system," Masafumi Nozawa, Akinobu Shimada, Toshifumi Nishimura, Katsuharu Kakuse, Tokuhiro Tsukiyama, Kiyoshi Yata, Yasuhiro Ishii, Kazuo Takaragi, Yasushi Kuba, Fujio Fujita, US5235641A, 1990-03-13.
５４）"Cryptographic communication method and system," Kazuo Takaragi, Yasuhiro Ishii, Tsutomu Nakamura, US5144665A, 1990-02-21.
５５）"Secret information service system and method," Kazuo Takaragi, Ryoichi Sasaki, Tsutomu Nakamura, Minoru Koizumi, Yasuko Fukuzawa, Kenji Kataoka, US5117458A, 1989-11-01.
５６）"Automatic trading method and apparatus," Kazuaki Tanaka, Takeshi Matsuki, Kazuo Takaragi, US5315634A, 1989-09-04.
５７）"System and method for performing interlocution at a plurality of terminals connected to communication network," Yoshiyuki Nakayama, Kenjiro Mori, Kazuo Takaragi, Singi Domen,US5280583A, 1988-05-13.
５８）"Encipher method and decipher method," Kazuo Takaragi, Fusao Nakagawa, Ryoichi Sasaki, US5103479A, 1988-04-28.
５９）"Encipher method and decipher method," Kazuo Takaragi, Fusao Nakagawa, Ryoichi Sasaki, US4982429A, 1988-04-28.
６０）"Encrypting system of data," Kazuo Takaragi, Fusao Nakagawa, Yasuhiko Nagai, Ryoichi Sasaki, US4969190A, 1988-04-13.
６１）"IC card," Kazuo Takaragi, Takayoshi Shiraishi, Ryoichi Sasaki, US4885788A, 1986-02-17.
６２）"Method for electronic transaction with digital signature," Kazuo Takaragi, Ryoichi Sasaki, US5018196A, 1985-09-04.
６３）"Electronic transaction system," Kazuo Takaragi, Ryoichi Sasaki, Takayoshi Shiraishi, Nobuhiro Kurashiki, US4885777A, 1985-09-04.
c.［Japan Domestic］
NA