Tatsuaki Okamoto

Tatsuaki Okamoto, Katsuyuki Takashima: Efficient (Hierarchical) Inner-Product Encryption Tightly Reduced from the Decisional Linear Assumption. IEICE Transactions 96-A(1): 42-52 (2013)

Takuho Mitsunaga, Yoshifumi Manabe, Tatsuaki Okamoto: Efficient Secure Auction Protocols Based on the Boneh-Goh-Nissim Encryption. IEICE Transactions 96-A(1): 68-75 (2013)

Masayuki Abe, Tatsuaki Okamoto, Koutarou Suzuki: Message Recovery Signature Schemes from Sigma-Protocols. IEICE Transactions 96-A(1): 92-100 (2013)

Eiichiro Fujisaki, Tatsuaki Okamoto: Secure Integration of Asymmetric and Symmetric Encryption Schemes. J. Cryptology 26(1): 80-101 (2013)

Tatsuaki Okamoto, Katsuyuki Takashima: Decentralized Attribute-Based Signatures. Public Key Cryptography 2013: 125-142

Yoshifumi Manabe, Tatsuaki Okamoto: Meta-envy-free Cake-cutting and Pie-cutting Protocols. JIP 20(3): 686-693 (2012)

Tatsuaki Okamoto, Katsuyuki Takashima: Fully Secure Unbounded Inner-Product and Attribute-Based Encryption. ASIACRYPT 2012: 349-366

Tatsuaki Okamoto, Katsuyuki Takashima: Adaptively Attribute-Hiding (Hierarchical) Inner Product Encryption. EUROCRYPT 2012: 591-608

Susumu Kiyoshima, Yoshifumi Manabe, Tatsuaki Okamoto: Efficient Concurrent Oblivious Transfer in Super-Polynomial-Simulation Security. IWSEC 2012: 216-232

Yoshifumi Manabe, Tatsuaki Okamoto: A Cryptographic Moving-Knife Cake-Cutting Protocol. IWIGP 2012: 15-23

Tatsuaki Okamoto, Katsuyuki Takashima: Fully Secure Unbounded Inner-Product and Attribute-Based Encryption. IACR Cryptology ePrint Archive 2012: 671 (2012)

Daisuke Moriyama, Tatsuaki Okamoto: An eCK-secure Authenticated Key Exchange Protocol without Random Oracles. TIIS 5(3): 607-625 (2011)

Tatsuaki Okamoto, Katsuyuki Takashima: Some Key Techniques on Pairing Vector Spaces. AFRICACRYPT 2011: 380-382

Tatsuaki Okamoto, Katsuyuki Takashima: Achieving Short Ciphertexts or Short Secret-Keys for Adaptively Secure General Inner-Product Encryption. CANS 2011: 138-159

Daisuke Moriyama, Tatsuaki Okamoto: Leakage resilient eCK-secure key exchange protocol without random oracles. ASIACCS 2011: 441-447

Takuho Mitsunaga, Yoshifumi Manabe, Tatsuaki Okamoto: A Secure M + 1st Price Auction Protocol Based on Bit Slice Circuits. IWSEC 2011: 51-64

Tatsuaki Okamoto, Katsuyuki Takashima: Efficient Attribute-Based Signatures for Non-monotone Predicates in the Standard Model. Public Key Cryptography 2011: 35-52

Tatsuaki Okamoto, Katsuyuki Takashima: Adaptively Attribute-Hiding (Hierarchical) Inner Product Encryption. IACR Cryptology ePrint Archive 2011: 543 (2011)

Tatsuaki Okamoto, Katsuyuki Takashima: Achieving Short Ciphertexts or Short Secret-Keys for Adaptively Secure General Inner-Product Encryption. IACR Cryptology ePrint Archive 2011: 648 (2011)

Tatsuaki Okamoto, Katsuyuki Takashima: Efficient Attribute-Based Signatures for Non-Monotone Predicates in the Standard Model. IACR Cryptology ePrint Archive 2011: 700 (2011)

Tatsuaki Okamoto, Katsuyuki Takashima: Decentralized Attribute-Based Signatures. IACR Cryptology ePrint Archive 2011: 701 (2011)

Masayuki Abe, Eike Kiltz, Tatsuaki Okamoto: Chosen Ciphertext Security with Optimal Ciphertext Overhead. IEICE Transactions 93-A(1): 22-33 (2010)

Tatsuaki Okamoto, Katsuyuki Takashima: Fully Secure Functional Encryption with General Relations from the Decisional Linear Assumption. CRYPTO 2010: 191-208

Allison B. Lewko, Tatsuaki Okamoto, Amit Sahai, Katsuyuki Takashima, Brent Waters: Fully Secure Functional Encryption: Attribute-Based Encryption and (Hierarchical) Inner Product Encryption. EUROCRYPT 2010: 62-91

Takuho Mitsunaga, Yoshifumi Manabe, Tatsuaki Okamoto: Efficient Secure Auction Protocols Based on the Boneh-Goh-Nissim Encryption. IWSEC 2010: 149-163

Yoshifumi Manabe, Tatsuaki Okamoto: Meta-Envy-Free Cake-Cutting Protocols. MFCS 2010: 501-512

Allison B. Lewko, Tatsuaki Okamoto, Amit Sahai, Katsuyuki Takashima, Brent Waters: Fully Secure Functional Encryption: Attribute-Based Encryption and (Hierarchical) Inner Product Encryption. IACR Cryptology ePrint Archive 2010: 110 (2010)

Tatsuaki Okamoto, Katsuyuki Takashima: Fully Secure Functional Encryption with General Relations from the Decisional Linear Assumption. IACR Cryptology ePrint Archive 2010: 563 (2010)

Tatsuaki Okamoto, Katsuyuki Takashima: Hierarchical Predicate Encryption for Inner-Products. ASIACRYPT 2009: 214-231

Masayuki Abe, Eike Kiltz, Tatsuaki Okamoto: Compact CCA-Secure Encryption for Messages of Arbitrary Length. Public Key Cryptography 2009: 377-392

Daisuke Moriyama, Tatsuaki Okamoto: An eCK-Secure Authenticated Key Exchange Protocol without Random Oracles. ProvSec 2009: 154-167

Ryo Nishimaki, Yoshifumi Manabe, Tatsuaki Okamoto: Universally Composable Identity-Based Encryption. IEICE Transactions 91-A(1): 262-271 (2008)

Waka Nagao, Yoshifumi Manabe, Tatsuaki Okamoto: On the Equivalence of Several Security Notions of KEM and DEM. IEICE Transactions 91-A(1): 283-297 (2008)

Yusuke Okada, Yoshifumi Manabe, Tatsuaki Okamoto: An optimistic fair exchange protocol and its security in the universal composability framework. IJACT 1(1): 70-77 (2008)

Masayuki Abe, Eike Kiltz, Tatsuaki Okamoto: Chosen Ciphertext Security with Optimal Ciphertext Overhead. ASIACRYPT 2008: 355-371

Norio Akagi, Yoshifumi Manabe, Tatsuaki Okamoto: An Efficient Anonymous Credential System. Financial Cryptography 2008: 272-286

Tatsuaki Okamoto, Katsuyuki Takashima: Homomorphic Encryption and Signatures from Vector Decomposition. Pairing 2008: 57-74

Waka Nagao, Yoshifumi Manabe, Tatsuaki Okamoto: Relationship of Three Cryptographic Channels in the UC Framework. ProvSec 2008: 268-282

Masayuki Abe, Eike Kiltz, Tatsuaki Okamoto: Chosen Ciphertext Security with Optimal Ciphertext Overhead. IACR Cryptology ePrint Archive 2008: 374 (2008)

Tatsuaki Okamoto: Authenticated Key Exchange and Key Encapsulation in the Standard Model. ASIACRYPT 2007: 474-484

Feng Bao, San Ling, Tatsuaki Okamoto, Huaxiong Wang, Chaoping Xing (Eds.): Cryptology and Network Security, 6th International Conference, CANS 2007, Singapore, December 8-10, 2007, Proceedings. Lecture Notes in Computer Science 4856, Springer 2007, isbn 978-3-540-76968-2

Tsuyoshi Takagi, Tatsuaki Okamoto, Eiji Okamoto, Takeshi Okamoto (Eds.): Pairing-Based Cryptography - Pairing 2007, First International Conference, Tokyo, Japan, July 2-4, 2007, Proceedings. Lecture Notes in Computer Science 4575, Springer 2007, isbn 978-3-540-73488-8

Tatsuaki Okamoto, Xiaoyun Wang (Eds.): Public Key Cryptography - PKC 2007, 10th International Conference on Practice and Theory in Public-Key Cryptography, Beijing, China, April 16-20, 2007, Proceedings. Lecture Notes in Computer Science 4450, Springer 2007, isbn 978-3-540-71676-1

Tatsuaki Okamoto: Authenticated Key Exchange and Key Encapsulation Without Random Oracles. IACR Cryptology ePrint Archive 2007: 473 (2007)

Waka Nagao, Yoshifumi Manabe, Tatsuaki Okamoto: A Universally Composable Secure Channel Based on the KEM-DEM Framework. IEICE Transactions 89-A(1): 28-38 (2006)

Tatsuaki Okamoto: Cryptography Based on Bilinear Maps. AAECC 2006: 35-50

Tatsuaki Okamoto: Efficient Blind and Partially Blind Signatures Without Random Oracles. TCC 2006: 80-99

Tatsuaki Okamoto: On Pairing-Based Cryptosystems. VIETCRYPT 2006: 50-66

Ryo Nishimaki, Yoshifumi Manabe, Tatsuaki Okamoto: Universally Composable Identity-Based Encryption. VIETCRYPT 2006: 337-353

Tatsuaki Okamoto: Efficient Blind and Partially Blind Signatures Without Random Oracles. IACR Cryptology ePrint Archive 2006: 102 (2006)

Waka Nagao, Yoshifumi Manabe, Tatsuaki Okamoto: On the Equivalence of Several Security Notions of Key Encapsulation Mechanism. IACR Cryptology ePrint Archive 2006: 268 (2006)

Chung-Huang Yang, Hikaru Morita, Tatsuaki Okamoto: Security and Performance Evaluation of ESIGN and RSA on IC Cards by Using Byte-Unit Modular Algorithms. IEICE Transactions 88-B(3): 1244-1248 (2005)

Waka Nagao, Yoshifumi Manabe, Tatsuaki Okamoto: A Universally Composable Secure Channel Based on the KEM-DEM Framework. TCC 2005: 426-444

Tatsuaki Okamoto, Ryo Kashima: Resource Bounded Unprovability of Computational Lower Bounds. CoRR abs/cs/0503091 (2005)

Eiichiro Fujisaki, Tatsuaki Okamoto, David Pointcheval, Jacques Stern: RSA-OAEP Is Secure under the RSA Assumption. J. Cryptology 17(2): 81-104 (2004)

Ryotaro Hayashi, Tatsuaki Okamoto, Keisuke Tanaka: An RSA Family of Trap-Door Permutations with a Common Domain and Its Applications. Public Key Cryptography 2004: 291-304

Tatsuaki Okamoto (Ed.): Topics in Cryptology - CT-RSA 2004, The Cryptographers' Track at the RSA Conference 2004, San Francisco, CA, USA, February 23-27, 2004, Proceedings. Lecture Notes in Computer Science 2964, Springer 2004, isbn 3-540-20996-4

Tatsuaki Okamoto, Jacques Stern: Almost Uniform Density of Power Residues and the Provable Security of ESIGN. ASIACRYPT 2003: 287-301

Tatsuaki Okamoto, Ryo Kashima: Resource Bounded Unprovability of Computational Lower Bounds. IACR Cryptology ePrint Archive 2003: 187 (2003)

Eiichiro Fujisaki, Tatsuaki Okamoto, David Pointcheval, Jacques Stern: RSA-OAEP Is Secure under the RSA Assumption. CRYPTO 2001: 260-274

Tatsuaki Okamoto, David Pointcheval: REACT: Rapid Enhanced-Security Asymmetric Cryptosystem Transform. CT-RSA 2001: 159-175

Tatsuaki Okamoto, David Pointcheval: The Gap-Problems: A New Class of Problems for the Security of Cryptographic Schemes. Public Key Cryptography 2001: 104-118

Sihan Qing, Tatsuaki Okamoto, Jianying Zhou (Eds.): Information and Communications Security, Third International Conference, ICICS 2001, Xian, China, November 13-16, 2001. Lecture Notes in Computer Science 2229, Springer 2001, isbn 3-540-42880-1

Tatsuaki Okamoto: On Relationships between Statistical Zero-Knowledge Proofs. J. Comput. Syst. Sci. 60(1): 47-108 (2000)

Tatsuaki Okamoto, Keisuke Tanaka, Shigenori Uchiyama: Quantum Public-Key Cryptosystems. CRYPTO 2000: 147-165

Masayuki Abe, Tatsuaki Okamoto: Provably Secure Partially Blind Signatures. CRYPTO 2000: 271-286

Tatsuaki Okamoto (Ed.): Advances in Cryptology - ASIACRYPT 2000, 6th International Conference on the Theory and Application of Cryptology and Information Security, Kyoto, Japan, December 3-7, 2000, Proceedings. Lecture Notes in Computer Science 1976, Springer 2000, isbn 3-540-41404-5

Eiichiro Fujisaki, Tatsuaki Okamoto, David Pointcheval, Jacques Stern: RSA-OAEP is Secure under the RSA Assumption. IACR Cryptology ePrint Archive 2000: 61 (2000)

Masayuki Abe, Tatsuaki Okamoto: A Signature Scheme with Message Recovery as Secure as Discrete Logarithm. ASIACRYPT 1999: 378-389

Eiichiro Fujisaki, Tatsuaki Okamoto: Secure Integration of Asymmetric and Symmetric Encryption Schemes. CRYPTO 1999: 537-554

Masayuki Abe, Tatsuaki Okamoto: Delegation Chains Secure up to Constant Length. ICICS 1999: 144-156

Miyako Ohkubo, Fumiaki Miura, Masayuki Abe, Atsushi Fujioka, Tatsuaki Okamoto: An Improvement on a Practical Secret Voting Scheme. ISW 1999: 225-234

Eiichiro Fujisaki, Tatsuaki Okamoto: How to Enhance the Security of Public-Key Encryption at Minimum Cost. Public Key Cryptography 1999: 53-68

Kazuo Ohta, Tatsuaki Okamoto: On Concrete Security Treatment of Signatures Derived from Identification. CRYPTO 1998: 354-369

Eiichiro Fujisaki, Tatsuaki Okamoto: A Practical and Provably Secure Scheme for Publicly Verifiable Secret Sharing and Its Applications. EUROCRYPT 1998: 32-46

Tatsuaki Okamoto, Shigenori Uchiyama: A New Public-Key Cryptosystem as Secure as Factoring. EUROCRYPT 1998: 308-318

Tatsuaki Okamoto, Shigenori Uchiyama: Security of an Identity-Based Cryptosystem and the Related Reductions. EUROCRYPT 1998: 546-560

Tatsuaki Okamoto, Moti Yung: Lower Bounds on Term-Based Divisible Cash Systems. Public Key Cryptography 1998: 72-82

Eiichiro Fujisaki, Tatsuaki Okamoto: Statistical Zero Knowledge Protocols to Prove Modular Polynomial Relations. CRYPTO 1997: 16-30

Giovanni Di Crescenzo, Tatsuaki Okamoto, Moti Yung: Keeping the SZK-Verifier Honest Unconditionally. CRYPTO 1997: 31-45

Tatsuaki Okamoto: Receipt-Free Electronic Voting Schemes for Large Scale Elections. Security Protocols Workshop 1997: 25-35

Tatsuaki Okamoto: Threshold Key-Recovery Systems for RSA. Security Protocols Workshop 1997: 191-200

Yongfei Han, Tatsuaki Okamoto, Sihan Qing (Eds.): Information and Communication Security, First International Conference, ICICS'97, Beijing, China, November 11-14, 1997, Proceedings. Lecture Notes in Computer Science 1334, Springer 1997, isbn 3-540-63696-X

Tatsuaki Okamoto: An electronic voting scheme. IFIP World Conference on IT Tools 1996: 21-30

Eiichiro Fujisaki, Tatsuaki Okamoto: Practical Escrow Cash System. Security Protocols Workshop 1996: 33-48

Tatsuaki Okamoto: On Relationships between Statistical Zero-Knowledge Proofs. STOC 1996: 649-658

Ivan Damgård, Oded Goldreich, Tatsuaki Okamoto, Avi Wigderson: Honest Verifier vs Dishonest Verifier in Public Coin Zero-Knowledge Proofs. CRYPTO 1995: 325-338

Tatsuaki Okamoto: An Efficient Divisible Electronic Cash Scheme. CRYPTO 1995: 438-451

Alfredo De Santis, Tatsuaki Okamoto, Giuseppe Persiano: Zero-Knowledge Proofs of Computational Power in the Shared String Model. ASIACRYPT 1994: 182-192

Tatsuaki Okamoto, Kazuo Ohta: How to Simultaneously Exchange Secrets by General Assumptions. ACM Conference on Computer and Communications Security 1994: 184-192

Tatsuaki Okamoto: Designated Confirmer Signatures and Public-Key Encryption are Equivalent. CRYPTO 1994: 61-74

Tony Eng, Tatsuaki Okamoto: Single-Term Divisible Electronic Coins. EUROCRYPT 1994: 306-319

Alfred Menezes, Tatsuaki Okamoto, Scott A. Vanstone: Reducing elliptic curve logarithms to logarithms in a finite field. IEEE Transactions on Information Theory 39(5): 1639-1646 (1993)

Choonsik Park, Kaoru Kurosawa, Tatsuaki Okamoto, Shigeo Tsujii: On Key Distribution and Authentication in Mobile Radio Networks. EUROCRYPT 1993: 461-465

Tatsuaki Okamoto: On the Relationship among Cryptographic Physical Assumptions. ISAAC 1993: 369-378

Atsushi Fujioka, Tatsuaki Okamoto, Kazuo Ohta: A Practical Secret Voting Scheme for Large Scale Elections. AUSCRYPT 1992: 244-251

Tatsuaki Okamoto: Provably Secure and Practical Identification Schemes and Corresponding Signature Schemes. CRYPTO 1992: 31-53

Tatsuaki Okamoto, Atsushi Fujioka, Eiichiro Fujisaki: An Efficient Digital Signature Scheme Based on an Elliptic Curve Over the Ring Z_n. CRYPTO 1992: 54-65

Kazuo Ohta, Tatsuaki Okamoto, Atsushi Fujioka: Secure Bit Commitment Function against Divertibility. EUROCRYPT 1992: 324-340

Tatsuaki Okamoto, Kouichi Sakurai, Hiroki Shizuya: How Intractable Is the Discrete Logarithm for a General Finite Group? EUROCRYPT 1992: 420-428

Kazuo Ohta, Tatsuaki Okamoto: A Digital Multisignature Scheme Based on the Fiat-Shamir Scheme. ASIACRYPT 1991: 139-148

Tatsuaki Okamoto: An Extensin of Zero-Knowledge Proofs and Its Applications. ASIACRYPT 1991: 368-381

Kenji Koyama, Ueli M. Maurer, Tatsuaki Okamoto, Scott A. Vanstone: New Public-Key Schemes Based on Elliptic Curves over the Ring Z_n. CRYPTO 1991: 252-266

Tatsuaki Okamoto, Kouichi Sakurai: Efficient Algorithms for the Construction of Hyperelliptic Cryptosystems. CRYPTO 1991: 267-278

Tatsuaki Okamoto, Kazuo Ohta: Universal Electronic Cash. CRYPTO 1991: 324-337

Tatsuaki Okamoto, David Chaum, Kazuo Ohta: Direct Zero Knowledge Proofs of Computational Power in Five Rounds. EUROCRYPT 1991: 96-105

Atsushi Fujioka, Tatsuaki Okamoto, Kazuo Ohta: Interactive Bi-Proof Systems and Undeniable Signature Schemes. EUROCRYPT 1991: 243-256

Atsushi Fujioka, Tatsuaki Okamoto, Shoji Miyaguchi: ESIGN: An Efficient Digital Signature Implementation for Smard Cards. EUROCRYPT 1991: 446-457

Alfred Menezes, Scott A. Vanstone, Tatsuaki Okamoto: Reducing Elliptic Curve Logarithms to Logarithms in a Finite Field. STOC 1991: 80-89

Tatsuaki Okamoto: A fast signature scheme based on congruential polynomial operations. IEEE Transactions on Information Theory 36(1): 47-53 (1990)

Tatsuaki Okamoto, Kazuo Ohta: How to Utilize the Randomness of Zero-Knowledge Proofs. CRYPTO 1990: 456-475

Kazuo Ohta, Tatsuaki Okamoto, Kenji Koyama: Membership Authentication for Hierarchical Multigroups Using the Extended Fiat-Shamir Scheme. EUROCRYPT 1990: 446-457

Tatsuaki Okamoto, Kazuo Ohta: Disposable Zero-Knowledge Authentications and Their Applications to Untraceable Electronic Cash. CRYPTO 1989: 481-496

Tatsuaki Okamoto, Kazuo Ohta: Divertible Zero Knowledge Interactive Proofs and Commutative Random Self-Reducibility. EUROCRYPT 1989: 134-148

Tatsuaki Okamoto: A Digital Multisignature Schema Using Bijective Public-Key Cryptosystems. ACM Trans. Comput. Syst. 6(4): 432-441 (1988)

Kazuo Ohta, Tatsuaki Okamoto: A Modification of the Fiat-Shamir Scheme. CRYPTO 1988: 232-243

Ichiro Suzuki, Y. Motohashi, Kenichi Taniguchi, Tadao Kasami, Tatsuaki Okamoto: Specification and Verification of Decentralized Daisy Chain Arbiters with omega-Extended Regular Expressions. Theor. Comput. Sci. 43: 277-291 (1986)