Takeshi SHIMOYAMA


A Setup-Free Threshold Encryption Scheme for the Bitcoin Protocol and Its Applications
Goichiro HANAOKA Yusuke SAKAI Toshiya SHIMIZU Takeshi SHIMOYAMA SeongHan SHIN 
Publication:   
Publication Date: 2020/01/01
Vol. E103-A  No. 1  pp. 150-164
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
threshold encryptionECDSABitcoinprovable securityimplementation
 Summary | Full Text:PDF

Key Length Estimation of Pairing-Based Cryptosystems Using ηT Pairing over GF(3n)
Naoyuki SHINOHARA Takeshi SHIMOYAMA Takuya HAYASHI Tsuyoshi TAKAGI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2014/01/01
Vol. E97-A  No. 1  pp. 236-244
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Foundations
Keyword: 
pairing-based cryptosystemsdiscrete logarithm problemfinite fieldkey length
 Summary | Full Text:PDF

Preimage Attacks on the Step-Reduced RIPEMD-128 and RIPEMD-160
Chiaki OHTAHARA Yu SASAKI Takeshi SHIMOYAMA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2012/10/01
Vol. E95-A  No. 10  pp. 1729-1739
Type of Manuscript:  PAPER
Category: Cryptography and Information Security
Keyword: 
RIPEMD-128RIPEMD-160hashpreimagemeet-in-the-middle
 Summary | Full Text:PDF

Forgery Attacks on Time-Stamp, Signed PDF and X.509 Certificate
Kouichi ITOH Tetsuya IZU Wakaha OGATA Takeshi SHIMOYAMA Masahiko TAKENAKA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2009/01/01
Vol. E92-A  No. 1  pp. 67-75
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Digital Signature
Keyword: 
Bleichenbacher's forgery attackRSASSA-PKCS-v1_5time-stampPDFX.509 certificateAcrobatAcrobat Reader
 Summary | Full Text:PDF

A Strict Evaluation on the Number of Conditions for SHA-1 Collision Search
Jun YAJIMA Terutoshi IWASAKI Yusuke NAITO Yu SASAKI Takeshi SHIMOYAMA Thomas PEYRIN Noboru KUNIHIRO Kazuo OHTA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2009/01/01
Vol. E92-A  No. 1  pp. 87-95
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Hash Function
Keyword: 
hash functioncollision searchSHA-1disturbance vector
 Summary | Full Text:PDF

Development of the Lead-Free Brush Material for the High-Load Starter
Ryoichi HONBO Youichi MURAKAMI Koichiro SAWA Hiroyuki WAKABAYASHI Naruhiko INAYOSHI Kyoji INUKAI Takeshi SHIMOYAMA Naoki MORITA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2007/08/01
Vol. E90-C  No. 8  pp. 1634-1642
Type of Manuscript:  PAPER
Category: Electromechanical Devices and Components
Keyword: 
carbon brushstarterleadweartribology
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Development of the Lead-Free Carbon Brush Material for Starters
Ryoichi HONBO Koichiro SAWA Youichi MURAKAMI Hiroyuki WAKABAYASHI Naruhiko INAYOSHI Kyoji INUKAI Takeshi SHIMOYAMA Naoki MORITA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2005/08/01
Vol. E88-C  No. 8  pp. 1675-1681
Type of Manuscript:  Special Section PAPER (Special Section on Recent Development of Electro-Mechanical Devices--Selected Papers from International Session on Electro-Mechanical Devices 2004 (IS-EMD2004)--)
Category: Automotive Application
Keyword: 
carbon brushlead freestarterwearcorrosion
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Theoretical Analysis of χ2 Attack on RC6
Masahiko TAKENAKA Takeshi SHIMOYAMA Takeshi KOSHIBA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2004/01/01
Vol. E87-A  No. 1  pp. 28-36
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Symmetric Cipher
Keyword: 
RC6χ2 attacktransition matrix
 Summary | Full Text:PDF

An Efficient Interpolation Attack
Shiho MORIAI Takeshi SHIMOYAMA Toshinobu KANEKO 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2000/01/25
Vol. E83-A  No. 1  pp. 39-47
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
cryptanalysisblock cipherinterpolation attackcomputer algebra systemSNAKE
 Summary | Full Text:PDF

Improved Higher Order Differential Attack and Its Application to Nyberg-Knudsen's Designed Block Cipher
Takeshi SHIMOYAMA Shiho MORIAI Toshinobu KANEKO Shigeo TSUJII 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1999/09/25
Vol. E82-A  No. 9  pp. 1971-1980
Type of Manuscript:  PAPER
Category: Information Security
Keyword: 
block cipherhigher order differential attackKN cipheralgebraic equation
 Summary | Full Text:PDF