Eisuke KOIZUMI


Autoreducibility and Completeness for Partial Multivalued Functions
Shuji ISOBE Eisuke KOIZUMI 
Publication:   
Publication Date: 2017/03/01
Vol. E100-D  No. 3  pp. 422-427
Type of Manuscript:  Special Section PAPER (Special Section on Foundations of Computer Science — New Trends in Theoretical Computer Science —)
Category: 
Keyword: 
partial multivalued functionautoreductionmany-one-like reduction
 Summary | Full Text:PDF(198.8KB)

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)

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
 Summary | Full Text:PDF(265.1KB)

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)