Shingo HASEGAWA


Black-Box Separations on Fiat-Shamir-Type Signatures in the Non-Programmable Random Oracle Model
Masayuki FUKUMITSU Shingo HASEGAWA 
Publication:   
Publication Date: 2018/01/01
Vol. E101-A  No. 1  pp. 77-87
Type of Manuscript:  Special Section PAPER (Special Section on Cryptography and Information Security)
Category: 
Keyword: 
Fiat-Shamir transformationnon-programmable random oracle modelmeta-reduction
 Summary | Full Text:PDF(1.2MB)

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)

A Lossy Identification Scheme Using the Subgroup Decision Assumption
Shingo HASEGAWA Shuji ISOBE 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2014/06/01
Vol. E97-A  No. 6  pp. 1296-1306
Type of Manuscript:  Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
lossy identification schemesthe Fiat-Shamir heuristicthe subgroup decision assumptionthe DCR assumption
 Summary | Full Text:PDF(356.5KB)

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)

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)

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
 Summary | Full Text:PDF(78.6KB)