Hiroki SHIZUYA


Computational Model of Card-Based Cryptographic Protocols and Its Applications
Takaaki MIZUKI Hiroki SHIZUYA 
Publication:   
Publication Date: 2017/01/01
Vol. E100-A  No. 1  pp. 3-11
Type of Manuscript:  INVITED PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
card-based protocolscard gamescryptography without computersreal-life hands-on cryptographysecure multiparty computations
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A Strengthened Security Notion for Password-Protected Secret Sharing Schemes
Shingo HASEGAWA Shuji ISOBE Jun-ya IWAZAKI Eisuke KOIZUMI Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2015/01/01
Vol. E98-A  No. 1  pp. 203-212
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Foundation
Keyword: 
password-protected secret sharingtwin ElGamal encryptionsimulation-sound non-interactive zero-knowledge
 Summary | Full Text:PDF(837.2KB)

On the Complexity of Computing Discrete Logarithms over Algebraic Tori
Shuji ISOBE Eisuke KOIZUMI Yuji NISHIGAKI Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Information and Systems
Publication Date: 2014/03/01
Vol. E97-D  No. 3  pp. 442-447
Type of Manuscript:  Special Section PAPER (Special Section on Foundations of Computer Science —New Trends in Theory of Computation and Algorithm—)
Category: Fundamentals of Information Systems
Keyword: 
algebraic toriorder certified discrete logarithmTuring reduction
 Summary | Full Text:PDF(381.4KB)

The RSA Group Is Adaptive Pseudo-Free under the RSA Assumption
Masayuki FUKUMITSU Shingo HASEGAWA Shuji ISOBE Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2014/01/01
Vol. E97-A  No. 1  pp. 200-214
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Public Key Based Cryptography
Keyword: 
pseudo-freenessadaptive pseudo-free groupsRSA assumption
 Summary | Full Text:PDF(606.3KB)

On the Length-Decreasing Self-Reducibility and the Many-One-Like Reducibilities for Partial Multivalued Functions
Ji-Won HUH Shuji ISOBE Eisuke KOIZUMI Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Information and Systems
Publication Date: 2013/03/01
Vol. E96-D  No. 3  pp. 465-471
Type of Manuscript:  Special Section PAPER (Special Section on Foundations of Computer Science — New Trends in Algorithms and Theory of Computation —)
Category: 
Keyword: 
partial multivalued functionlength-decreasing self-reductionmany-one-like reduction
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NPMV-Complete Functions That Compute Discrete Logarithms and Integer Factorization
Shingo HASEGAWA Shuji ISOBE Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2008/01/01
Vol. E91-A  No. 1  pp. 342-344
Type of Manuscript:  Special Section LETTER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
NPMVNPMV-completediscrete logarithminteger factoring
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Making Cryptographic Primitives Harder
Shingo HASEGAWA Hiroyuki HATANAKA Shuji ISOBE Eisuke KOIZUMI Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2008/01/01
Vol. E91-A  No. 1  pp. 330-337
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Cryptanalysis
Keyword: 
liftingsmultivalued functionsdiscrete logarithmgraph isomorphism
 Summary | Full Text:PDF(308.7KB)

Toward Separating Integer Factoring from Discrete Logarithm mod p
Shuji ISOBE Wataru KUMAGAI Masahiro MAMBO Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2007/01/01
Vol. E90-A  No. 1  pp. 48-53
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Foundations
Keyword: 
preimage functionsrange injection reductionthe Heath-Brown conjectureinteger factoringcertified discrete logarithm
 Summary | Full Text:PDF(328.2KB)

On the Polynomial Time Computability of Abstract Ray-Tracing Problems
Shuji ISOBE Tetsuo KURIYAMA Masahiro MAMBO Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2005/05/01
Vol. E88-A  No. 5  pp. 1209-1213
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
ray-tracing problemabstract ray-tracing problem (ARTP)PSPACE-hard/completescene
 Summary | Full Text:PDF(176.6KB)

The Computational Difficulty of Solving Cryptographic Primitive Problems Related to the Discrete Logarithm Problem
Chisato KONOMA Masahiro MAMBO Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2005/01/01
Vol. E88-A  No. 1  pp. 81-88
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Public Key Cryptography
Keyword: 
discrete logarithm problemdouble discrete logarithm problemsquare root of discrete logarithm probleme-th root of discrete logarithm problem
 Summary | Full Text:PDF(193.3KB)

Complexity Analysis of the Cryptographic Primitive Problems through Square-Root Exponent
Chisato KONOMA Masahiro MAMBO Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2004/05/01
Vol. E87-A  No. 5  pp. 1083-1091
Type of Manuscript:  Special Section LETTER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
square-root exponentdiscrete logarithm problemfactoring problemDiffie-Hellman problemcomputing problemdecision problem
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On the Strength of the Strong RSA Assumption
Shintaro ITAGAKI Masahiro MAMBO Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2003/05/01
Vol. E86-A  No. 5  pp. 1164-1170
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
strong RSA assumptionRSAalgebraic computationstraight-line program
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On the Security of Girault Key Agreement Protocols against Active Attacks
Soo-Hyun OH Masahiro MAMBO Hiroki SHIZUYA Dong-Ho WON 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2003/05/01
Vol. E86-A  No. 5  pp. 1181-1189
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
self-certified public keyGirault key agreement protocolreduction
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A Note on the Relationships among Certified Discrete Log Cryptosystems
Eikoh CHIDA Toshiya ITOH Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2003/05/01
Vol. E86-A  No. 5  pp. 1198-1202
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
certified discrete logarithm problemorderprimitive rootprobabilistic reducibilitydeterministic reducibility
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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)

FOREWORD
Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2001/01/01
Vol. E84-A  No. 1  pp. 107-107
Type of Manuscript:  FOREWORD
Category: 
Keyword: 
 Summary | Full Text:PDF(141.4KB)

On the Complexity of Constructing an Elliptic Curve of a Given Order
Masato YAMAMICHI Masahiro MAMBO Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2001/01/01
Vol. E84-A  No. 1  pp. 140-145
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
elliptic curvefunction classcomputational complexity
 Summary | Full Text:PDF(215.8KB)

A Way of Making Trapdoor One-Way Functions Trapdoor No-Way
Eikoh CHIDA Motoji OHMORI Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2001/01/01
Vol. E84-A  No. 1  pp. 151-156
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
one-way functionno-way functiontrapdoor
 Summary | Full Text:PDF(212.5KB)

On the Average Length of Secret Key Exchange Eulerian Circuits
Takaaki MIZUKI Zhi-Bo SUI Hiroki SHIZUYA Takao NISHIZEKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2000/04/25
Vol. E83-A  No. 4  pp. 662-670
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
card gameEulerian graphinformation-theoretically securekey set protocolsecret key exchange
 Summary | Full Text:PDF(624.1KB)

A Note on the Complexity of Breaking Okamoto-Tanaka ID-Based Key Exchange Scheme
Masahiro MAMBO Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1999/01/25
Vol. E82-A  No. 1  pp. 77-80
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
key exchange schemeOkamoto-TanakaDiffie-HellmanRSAreducibility
 Summary | Full Text:PDF(121.5KB)

On the Difficulty of Searching for a String without Decryption
Takako ITO Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1999/01/25
Vol. E82-A  No. 1  pp. 134-137
Type of Manuscript:  Special Section LETTER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
one-way functionshard-core predicates
 Summary | Full Text:PDF(104.6KB)

On the Complexity of the Discrete Logarithm for a General Finite Group
Tatsuaki OKAMOTO Kouichi SAKURAI Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1996/01/25
Vol. E79-A  No. 1  pp. 61-65
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
discrete logarithmcomputational complexitycryptography
 Summary | Full Text:PDF(504.7KB)

On the One-Way Algebraic Homomorphism
Eikoh CHIDA Takao NISHIZEKI Motoji OHMORI Hiroki SHIZUYA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1996/01/25
Vol. E79-A  No. 1  pp. 54-60
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
one-way functionhomomorphismcryptography
 Summary | Full Text:PDF(653.9KB)

One-Way Functions over Finite Near-Rings
Eikoh CHIDA Hiroki SHIZUYA Takao NISHIZEKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1995/01/25
Vol. E78-A  No. 1  pp. 4-10
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
one-way functionsring homomorphismcryptography
 Summary | Full Text:PDF(594KB)

A Note on AM Languages Outside NP co-NP
Hiroki SHIZUYA Toshiya ITOH 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1994/01/25
Vol. E77-A  No. 1  pp. 65-71
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
Arthur-Merlin gamegraph isomorphismgraph heterogeneity
 Summary | Full Text:PDF(587KB)

Demonstrating Possession without Revealing Factors
Hiroki SHIZUYA Kenji KOYAMA Toshiya ITOH 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1994/01/25
Vol. E77-A  No. 1  pp. 39-46
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
zero-knowledge prooffactoringdiscrete logarithm
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Composite Noise Generator (CNG) with Random Pulse Stream (RPS) Generator for Immunity Test in Digital System
Hideo SUZUKI Hiroki SHIZUYA Tasuku TAKAGI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1992/03/25
Vol. E75-B  No. 3  pp. 183-187
Type of Manuscript:  Special Section PAPER (Special Issue on Measurements and Control of Electromagnetic Interference)
Category: 
Keyword: 
noise immunitynon-Gaussian noiseMiddleton's Class A noiseAPDrandom pulse
 Summary | Full Text:PDF(343.6KB)

On the Complexity of Hyperelliptic Discrete Logarithm Problem
Hiroki SHIZUYA Toshiya ITOH Kouichi SAKURAI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1991/08/25
Vol. E74-A  No. 8  pp. 2129-2135
Type of Manuscript:  Special Section PAPER (Special Issue on Cryptography and Information Security)
Category: 
Keyword: 
 Summary | Full Text:PDF(533.8KB)

A Group-Theoretic Interface to Random Self-Reducibility
Hiroki SHIZUYA Toshiya ITOH 
Publication:   IEICE TRANSACTIONS (1976-1990)
Publication Date: 1990/07/25
Vol. E73-E  No. 7  pp. 1087-1091
Type of Manuscript:  Special Section PAPER (Special Issue on Cryptography and Information Security)
Category: Authentication Techniques
Keyword: 
 Summary | Full Text:PDF(476.7KB)

An Argumental Expression of Correlation Function between Arbitrary Codewords
Hiroki SHIZUYA Hideaki SONE Hiroshi ECHIGO Tasuku TAKAGI 
Publication:   IEICE TRANSACTIONS (1976-1990)
Publication Date: 1986/12/25
Vol. E69-E  No. 12  pp. 1294-1302
Type of Manuscript:  PAPER
Category: Signal Processing and Theory
Keyword: 
 Summary | Full Text:PDF(580.6KB)