Faculty Profiles - IWATA Tetsu

Papers - IWATA Tetsu

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Practical committing attacks against Rocca-S Reviewed

Ryunosuke Takeuchi, Yosuke Todo, and Tetsu Iwata

Inf. Proc. Letters Vol. 192 ( 106610 ) 2026.2

Vector-Input Hashing Modes for Collision-Resistant Pseudorandom Function Reviewed

Shoichi Hirose, Tetsu Iwata, and Hidenori Kuwakado

Information Security and Cryptology - ICISC 2025 Vol. LNCS 2025.11

Type-2 Generalized Feistel Structures Based on Tweakable Block Ciphers, Reconsidered Reviewed

Kento Tsuji and Tetsu Iwata

IACR Communications in Cryptology (CiC) Vol. Vol. 2025 ( Issue 3 ) page： 1 - 29 2025.10

Cryptographic Treatment of Key Control Security - In Light of NIST SP 800-108 Reviewed International coauthorship

Ritam Bhaumik, Avijit Dutta, Akiko Inoue, Tetsu Iwata, Ashwin Jha, Kazuhiko Minematsu, Mridul Nandi, Yu Sasaki, Meltem Sönmez Turan, and Stefano Tessaro

Advances in Cryptology - CRYPTO 2025 Vol. LNCS 16004 page： 371 - 403 2025.8

Comprehensive Robustness Analysis of GCM, CCM, and OCB3 Reviewed

Akiko Inoue, Tetsu Iwata, and Kazuhiko Minematsu

Topics in Cryptology - CT-RSA 2025 ( LNCS 15598 ) page： 75 - 98 2025.4

Feistel Ciphers Based on a Single Primitive Reviewed

Kento Tsuji and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E107-A ( No. 8 ) page： 1229 - 1240 2024.8

Key Recovery, Universal Forgery, and Committing Attacks against Revised Rocca: How Finalization Affects Security Reviewed

Ryunosuke Takeuchi, Yosuke Todo, and Tetsu Iwata

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2024 ( Issue 2 ) page： 85 - 117 2024.6

Key Committing Security of AEZ and More Reviewed International coauthorship Open Access

Yu Long Chen, Antonio Florez-Gutierrez, Akiko Inoue, Ryoma Ito, Tetsu Iwata, Kazuhiko Minematsu, Nicky Mouha, Yusuke Naito, Ferdinand Sibleyras, and Yosuke Todo

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2023 ( Issue 4 ) page： 452 - 488 2023.12

Feistel Ciphers Based on a Single Primitive Reviewed

Kento Tsuji and Tetsu Iwata

Cryptography and Coding, 19th IMA International Conference, IMACC 2023, Lecture Notes in Computer Science, Springer ( LNCS 14421 ) page： 57 - 79 2023.12

PMACrx: A Vector-Input MAC for High-Dimensional Vectors with BBB Security Reviewed

Isamu Furuya, Hayato Kasahara, Akiko Inoue, Kazuhiko Minematsu, and Tetsu Iwata

Advances in Information and Computer Security, IWSEC 2023, Lecture Notes in Computer Science, Springer ( LNCS 14128 ) page： 77 - 97 2023.8

Generalized Feistel Structures based on Tweakable Block Ciphers Reviewed Open Access

Kazuki Nakaya and Tetsu Iwata

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2022 ( Issue 4 ) page： 24 - 91 2022.12

Cryptanalysis of Rocca and Feasibility of Its Security Claim Reviewed Open Access

Akinori Hosoyamada, Akiko Inoue, Ryoma Ito, Tetsu Iwata, Kazuhiko Mimematsu, Ferdinand Sibleyras, and Yosuke Todo

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2022 ( Issue 3 ) page： 123 - 151 2022.9

Matching attacks on Romulus-M Reviewed Open Access

Makoto Habu, Kazuhiko Minematsu, and Tetsu Iwata

IET Inf. Secur. Vol. 16 ( 6 ) page： 459 - 469 2022.7

Analyzing the Provable Security Bounds of GIFT-COFB and Photon-Beetle Reviewed

Akiko Inoue, Tetsu Iwata, and Kazuhiko Minematsu

Applied Cryptography and Network Security, ACNS 2022, Lecture Notes in Computer Science, Springer ( LNCS 13269 ) page： 67 - 84 2022.6

New indifferentiability security proof of MDPH hash function Reviewed International coauthorship Open Access

Chun Guo, Tetsu Iwata, and Kazuhiko Minematsu

IET Inf. Secur. page： 1 - 20 2022.3

On the (Im)possibility of Improving the Round Diffusion of Generalized Feistel Structures Reviewed Open Access

Kyoji Shibutani and Tetsu Iwata

Inf. Proc. Letters Vol. 174 ( 106197 ) 2022.3

Quantum Attacks on Sum of Even-Mansour Pseudorandom Functions Reviewed Open Access

Kazuo Shinagawa and Tetsu Iwata

Inf. Proc. Letters Vol. 173 ( 106172 ) 2022.1

Indifferentiability of SKINNY-HASH Internal Functions Reviewed

Akinori Hosoyamada and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E104-A ( No. 9 ) page： 1156 - 1162 2021.9

On Tight Quantum Security of HMAC and NMAC in the Quantum Random Oracle Model Reviewed

Akinori Hosoyamada and Tetsu Iwata

Advances in Cryptology - CRYPTO 2021 Vol. LNCS 12825 page： 585 - 615 2021.8

Provably Quantum-Secure Tweakable Block Ciphers Reviewed Open Access

Akinori Hosoyamada and Tetsu Iwata

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2021 ( Issue 1 ) page： 337 - 377 2021.3

Cryptanalysis of OCB2: Attacks on Authenticity and Confidentiality Invited Reviewed International coauthorship

Akiko Inoue, Tetsu Iwata, Kazuhiko Minematsu, Bertram Poettering

Journal of Cryptology Vol. 33 page： 1871 - 1913 2020.10

Beyond-Birthday-Bound Secure Cryptographic Permutations from Ideal Ciphers with Long Keys Reviewed

Ryota Nakamichi and Tetsu Iwata

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2020 ( Issue 2 ) page： 68-92 2020.7

Blockcipher-Based Authenticated Encryption: How Small Can We Go? Invited Reviewed International coauthorship

Chakraborti Avik, Iwata Tetsu, Minematsu Kazuhiko, Nandi Mridul

Journal of Cryptology Vol. 33 ( 3 ) page： 703-741 2020.7

Duel of the Titans: The Romulus and Remus Families of Lightweight AEAD Algorithms Reviewed International coauthorship

Tetsu Iwata, Mustafa Khairallah, Kazuhiko Minematsu, and Thomas Peyrin

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2020 ( Issue 1 ) page： 43-120 2020.5

Iterative Block Ciphers from Tweakable Block Ciphers with Long Tweaks Reviewed

Ryota Nakamichi and Tetsu Iwata

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2019 ( Issue 4 ) page： 54-80 2020.1

Quantum Attacks against Type-1 Generalized Feistel Ciphers and Applications to CAST-256 Reviewed

Boyu Ni, Gembu Ito, Xiaoyang Dong, and Tetsu Iwata

INDOCRYPT 2019, Lecture Notes in Computer Science, Springer ( LNCS 11898 ) page： 433-455 2019.12

4-Round Luby-Rackoff Construction is a qPRP Reviewed

Akinori Hosoyamada and Tetsu Iwata

ASIACRYPT 2019, Lecture Notes in Computer Science, Springer ( LNCS 11921 ) page： 145-174 2019.12

Cryptanalysis of OCB2: Attacks on Authenticity and Confidentiality Reviewed

Inoue Akiko, Iwata Tetsu, Minematsu Kazuhiko, Poettering Bertram

Advances in Cryptology, CRYPTO 2019 Vol. 11692 page： 3-31 2019.8

ZOCB and ZOTR: Tweakable Blockcipher Modes for Authenticated Encryption with Full Absorption Reviewed

Zhenzhen Bao, Jian Guo, Tetsu Iwata, and Kazuhiko Minematsu

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2019 ( Issue 2 ) page： 1-54 2019.6

Quantum Chosen-Ciphertext Attacks Against Feistel Ciphers Reviewed

Gembu Ito, Akinori Hosoyamada, Ryutaroh Matsumoto, Yu Sasaki, and Tetsu Iwata

CT-RSA 2019 ( LNCS 11405 ) page： 391-411 2019.3

Universal Forgery and Multiple Forgeries of MergeMAC and Generalized Constructions Reviewed

Tetsu Iwata, Virginie Lallemand, Gregor Leander, and Yu Sasaki

CT-RSA 2019 ( LNCS 11405 ) page： 293-312 2019.3

Integrity Analysis of Authenticated Encryption Based on Stream Ciphers Reviewed

Kazuya Imamura, Kazuhiko Minematsu, and Tetsu Iwata

International Journal of Information Security, IJIS Vol. 17 ( 5 ) page： 493-511 2018.10

Cryptanalysis of AES-PRF and Its Dual Reviewed

Patrick Derbez, Tetsu Iwata, Ling Sun, Siwei Sun, Yosuke Todo, Haoyang Wang, and Meiqin Wang

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2018 ( Issue 2 ) page： 161-191 2018.6

On the Design Rationale of SIMON Block Cipher: Integral Attacks and Impossible Differential Attacks against SIMON Variants Reviewed

Kota Kondo, Yu Sasaki, Yosuke Todo, and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E101-A ( No. 1 ) page： 88-98 2018.1

Reconsidering the Security Bound of AES-GCM-SIV Reviewed

Tetsu Iwata and Yannick Seurin

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2017 ( Issue 4 ) page： 240-267 2017.12

On the Security of Non-interactive Key Exchange against Related-Key Attacks Reviewed

Hiraku Morita, Jacob C.N. Schuldt, Takahiro Matsuda, Goichiro Hanaoka, and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E100-A ( No. 9 ) page： 1910-1923 2017.9

Blockcipher-Based Authenticated Encryption: How Small Can We Go? Reviewed

Avik Chakrabort, Tetsu Iwata, Kazuhiko Minematsu, and Mridul Nandi

CHES 2017, Lecture Notes in Computer Science, Springer ( LNCS 10529 ) page： 277-298 2017.9

Analyzing Key Schedule of Simon: Iterative Key Differences and Application to Related-Key Impossible Differentials Reviewed

Kota Kondo, Yu Sasaki, Yosuke Todo, and Tetsu Iwata

IWSEC 2017, Lecture Notes in Computer Science, Springer ( LNCS 10418 ) page： 141-158 2017.8

ZMAC: A Fast Tweakable Block Cipher Mode for Highly Secure Message Authentication Reviewed

Tetsu Iwata, Kazuhiko Minematsu, Thomas Peyrin, and Yannick Seurin

CRYPTO 2017, Lecture Notes in Computer Science, Springer ( LNCS 10403 ) page： 34-65 2017.8

Cryptanalysis of PMACx, PMAC2x, and SIVx Reviewed

Kazuhiko Minematsu and Tetsu Iwata

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2017 ( Issue 2 ) page： 162-176 2017.6

Stronger Security Variants of GCM-SIV Reviewed

Tetsu Iwata and Kazuhiko Minematsu

IACR Transactions on Symmetric Cryptology (ToSC) Vol. Vol. 2016 ( Issue 2 ) page： 134-157 2017.3

On the Security of Schnorr Signatures, DSA, and ElGamal Signatures against Related-Key Attacks Reviewed

Hiraku Morita, Jacob C.N. Schuldt, Takahiro Matsuda, Goichiro Hanaoka, and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E100-A ( No. 1 ) page： 73-90 2017.1

Blockcipher-Based Authenticated Encryption: How Small Can We Go?

Chakraborti Avik, Iwata Tetsu, Minematsu Kazuhiko, Nandi Mridul

CRYPTOGRAPHIC HARDWARE AND EMBEDDED SYSTEMS - CHES 2017 Vol. 10529 page： 277-298 2017

Integrity Analysis of Authenticated Encryption Based on Stream Ciphers Reviewed

Kazuya Imamura, Kazuhiko Minematsu, and Tetsu Iwata

ProvSec 2016, Lecture Notes in Computer Science, Springer ( LNCS 10005 ) page： 257-276 2016.11

On the Design Rationale of Simon Block Cipher: Integral Attacks and Impossible Differential Attacks against Simon Variants Reviewed

Kota Kondo, Yu Sasaki, and Tetsu Iwata

Applied Cryptography and Network Security, ACNS 2016, Lecture Notes in Computer Science, Springer ( LNCS 9696 ) page： 518-536 2016.6

Tweak-Length Extension for Tweakable Blockciphers Reviewed

Kazuhiko Minematsu and Tetsu Iwata

Cryptography and Coding, IMACC 2015, Lecture Notes in Computer Science, Springer ( LNCS 9496 ) page： 77-93 2015.12

On the Security of the Schnorr Signature Scheme and DSA Against Related-Key Attacks Reviewed

Hiraku Morita, Jacob C. N. Schuldt, Takahiro Matsuda, Goichiro Hanaoka, and Tetsu Iwata

Information Security and Cryptology, ICISC 2015, Lecture Notes in Computer Science, Springer ( LNCS 9558 ) page： 20-35 2015.11

Optimality of Tweak Functions in CLOC Reviewed

Hayato Kobayashi, Kazuhiko Minematsu, and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E98-A ( No. 10 ) page： 2152-2164 2015.10

GCM security bounds reconsidered Reviewed

Yuichi Niwa, Keisuke Ohashi, Kazuhiko Minematsu, and Tetsu Iwata

Fast Software Encryption, FSE 2015, Lecture Notes in Computer Science, Springer ( LNCS 9054 ) page： 385-407 2015.3

Type 1.x generalized Feistel structures Reviewed

Shingo Yanagihara and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E97-A ( No. 4 ) page： 952-963 2014.4

Impact of ANSI X9.24-1:2009 key check value on ISO/IEC 9797-1:2011 MACs Reviewed

Tetsu Iwata and Lei Wang

Fast Software Encryption, FSE 2014, Lecture Notes in Computer Science, Springer ( LNCS ) page： - 2014.3

CLOC: Authenticated encryption for short input Reviewed

Tetsu Iwata, Kazuhiko Minematsu, Jian Guo, and Sumio Morioka

Fast Software Encryption, FSE 2014, Lecture Notes in Computer Science, Springer ( LNCS ) page： - 2014.3

Cryptanalysis of 249-, 250-,..., 256-bit key HyRAL via equivalent keys Reviewed

Yuki Asano, Shingo Yanagihara, and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E97-A ( No. 1 ) page： 371-383 2014.1

Improved authenticity bound of EAX, and refinements Reviewed

Kazuhiko Minematsu, Stefan Lucks, and Tetsu Iwata

ProvSec 2013, Lecture Notes in Computer Science, Springer ( LNCS 8209 ) page： 284-201 2013.10

Type 1.x generalized Feistel structures Reviewed

Shingo Yanagihara and Tetsu Iwata

Pre-proceedings of International Workshop on Coding and Cryptography, WCC 2013 page： - 2013.4

Attacks and security proofs of EAX-prime Reviewed

Kazuhiko Minematsu, Stefan Lucks, Hiraku Morita, and Tetsu Iwata

Fast Software Encryption, FSE 2013, Lecture Notes in Computer Science, Springer ( LNCS ) page： - 2013.3

Improving the permutation layer of type 1, type 3, source-heavy, and target-heavy generalized Feistel structures Reviewed

Shingo Yanagihara and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E96-A ( No. 1 ) page： 2-14 2013.1

Breaking and repairing GCM security proofs Reviewed

Tetsu Iwata, Keisuke Ohashi, and Kazuhiko Minematsu

CRYPTO 2012, Lecture Notes in Computer Science, Springer ( LNCS 7417 ) page： 31–49 2012.8

Cryptanalysis of EAX-prime Reviewed

Kazuhiko Minematsu, Stefan Lucks, Hiraku Morita, and Tetsu Iwata

Workshop records of Directions in Authenticated Ciphers (DIAC) page： 3-13 2012.7

How fast can a two-pass mode go? A parallel deterministic authenticated encryption mode for AES-NI (Extended abstract of work in progress) Reviewed

Kazumaro Aoki, Tetsu Iwata, and Kan Yasuda

Workshop records of Directions in Authenticated Ciphers (DIAC) page： 35-43 2012.7

Cryptanalysis of 256-bit key HyRAL via equivalent keys Reviewed

Yuki Asano, Shingo Yanagihara, and Tetsu Iwata

ACNS 2012, Lecture Notes in Computer Science, Springer ( LNCS 7341 ) page： 257–274 2012.6

Further more on key wrapping Reviewed

Yasushi Osaki and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E95-A ( No. 1 ) page： 8-20 2012.1

On permutation layer of Type 1, Source-Heavy, Target-Heavy Generalized Feistel structures Reviewed

Shingo Yanagihara and Tetsu Iwata

CANS 2011, Lecture Notes in Computer Science, Springer ( LNCS 7092 ) page： 98-117 2011.12

Security of Hash-then-CBC Key wrapping revisited Reviewed

Yasushi Osaki and Tetsu Iwata

IMACC 2011, Lecture Notes in Computer Science, Springer ( LNCS 7089 ) page： 413-430 2011.12

Building blockcipher from tweakable Blockcipher: Extending FSE 2009 proposal Reviewed

Kazuhiko Minematsu and Tetsu Iwata

IMACC 2011, Lecture Notes in Computer Science, Springer ( LNCS 7089 ) page： 391-412 2011.12

Further more on key wrapping Reviewed

Yasushi Osaki and Tetsu Iwata

Conference record of Symmetric Key Encryption Workshop (SKEW) 2011 page： 1-20 2011.2

MPP characteristics of variants of Merkle-Damg{\aa}rd iterated hash functions Reviewed

Shungo Nakamura and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E93-A ( No. 1 ) page： 93-101 2010.1

Tweakable pseudorandom permutation from generalized Feistel structure Reviewed

Atsushi Mitsuda and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E93-A ( No. 1 ) page： 13-21 2010.1

*BTM: A single-key, inverse-cipher-free mode for deterministic authenticated encryption Reviewed

Tetsu Iwata and Kan Yasuda

Selected Areas in Cryptography, SAC 2009, Lecture Notes in Computer Science, Springer ( LNCS 5867 ) page： 313-330 2009.8

Language：English

We present a new blockcipher mode of operation named BTM, which stands for Bivariate Tag Mixing. BTM falls into the category of Deterministic Authenticated Encryption, which we call DAE for short. BTM makes all-around improvements over the previous two DAE constructions, SIV (Eurocrypt 2006) and HBS (FSE 2009). Specifically, our BTM requires just one blockcipher key, whereas SIV requires two.
Our BTM does not require the decryption algorithm of the underlying blockcipher, whereas HBS does. The BTM mode utilizes bivariate polynomial hashing for authentication, which enables us to handle vectorial inputs of dynamic dimensions. BTM then generates an initial value for its countermode of encryption by mixing the resulting tag with one of the two variables (hash keys), which avoids the need for an implementation of the inverse cipher.

*HBS: A single-key mode of operation for deterministic authenticated encryption Reviewed

Tetsu Iwata and Kan Yasuda

Fast Software Encryption, FSE 2009, Lecture Notes in Computer Science, Springer ( LNCS 5665 ) page： 394-415 2009.2

Authorship：Lead author Language：English

We propose the HBS (Hash Block Stealing) mode of operation. This is the first single-key mode that provably achieves the goal of providing deterministic authenticated encryption. The authentication part of HBS utilizes a newly-developed, vector-input polynomial hash function. The encryption part uses a blockcipher-based, counter-like mode. These two parts are combined in such a way as the numbers of finite-field multiplications and blockcipher calls are minimized. Specifically, for a header of h blocks and a message of m blocks, the HBS algorithm requires just h + m + 2 multiplications in the finite field and m + 2 calls to the blockcipher. Although the HBS algorithm is fairly simple, its security proof is rather complicated.

Tweakable pseudorandom permutation from generalized Feistel structure Reviewed

Atsushi Mitsuda and Tetsu Iwata

Second International Conference, ProvSec 2008, Lecture Notes in Computer Science, Springer ( LNCS 5324 ) page： 22-37 2008.10

Bounds on fixed input/output length post-processing functions for biased physical random number generators Reviewed

Kyohei Suzuki and Tetsu Iwata

Selected Areas in Cryptography, SAC 2008, Lecture Notes in Computer Science, Springer ( LNCS 5381 ) page： 373-386 2008.8

Authenticated encryption mode for beyond the birthday bound security Reviewed

Tetsu Iwata

Progress in Cryptology, AFRICACRYPT 2008, Lecture Notes in Computer Science, Springer ( LNCS 5023 ) page： 125-142 2008.6

Security of the five-round KASUMI type permutation Reviewed

Tetsu Iwata, Tohru Yagi and Kaoru Kurosawa

IEICE Trans. Fundamentals Vol. Vol. E91-A ( No. 1 ) page： 30-38 2008.1

*The 128-bit blockcipher CLEFIA Reviewed

Taizo Shirai, Kyoji Shibutani, Toru Akishita, Shiho Moriai and Tetsu Iwata

Fast Software Encryption, FSE 2007, Lecture Notes in Computer Science, Springer ( LNCS 4593 ) page： 181-195 2007.3

How to construct super-pseudorandom permutations with short keys Reviewed

Tetsu Iwata and Kaoru Kurosawa

IEICE Trans. Fundamentals Vol. Vol. E90-A ( No. 1 ) page： 2-13 2007.1

Side channel attacks on message authentication codes Reviewed

Katsuyuki Okeya and Tetsu Iwata

IPSJ Journal Vol. Vol. 47 ( No. 8 ) page： 2571-2581 2006.8

*New blockcipher modes of operation with beyond the birthday bound security Reviewed

Tetsu Iwata

Fast Software Encryption, FSE 2006, Lecture Notes in Computer Science, Springer ( LNCS 4047 ) page： 310-327 2006.3

Authorship：Lead author Language：English

In this paper, we define and analyze a new blockcipher mode of operation for encryption, CENC, which stands for Cipher-based ENCryption. CENC has the following advantages: (1) beyond the birthday bound security, (2) security proofs with the standard PRP assumption, (3) highly efficient, (4) single blockcipher key, (5) fully parallelizable, (6) allows precomputation of keystream, and (7) allows random access. CENC is based on the new construction of "from PRPs to PRF conversion," which is of independent interest. Based on CENC and a universal hash-based MAC (Wegman-Carter MAC), we also define a new authenticated-encryption with associated-data scheme, CHM, which stands for CENC with Hash-based MAC. The
security of CHM is also beyond the birthday bound.

Side channel attacks on message authentication codes Reviewed

Katsuyuki Okeya and Tetsu Iwata

Security and Privacy in Ad-hoc and Sensor Networks, ESAS 2005, Lecture Notes in Computer Science, Springer ( LNCS 3813 ) page： 205-217 2005.6

How to enhance the security of the 3GPP confidentiality and integrity algorithms Reviewed

Tetsu Iwata and Kaoru Kurosawa

Fast Software Encryption, FSE 2005, Lecture Notes in Computer Science, Springer ( LNCS 3557 ) page： 268-283 2005.2

How to improve interpolation attack Reviewed

Kaoru Kurosawa, Tetsu Iwata and Quang Viet Duong

IEICE Trans. Fundamentals Vol. Vol. E88-A ( No. 1 ) page： 9-15 2005.1

On the security of a MAC by Mitchell Reviewed

Tetsu Iwata and Kaoru Kurosawa

IEICE Trans. Fundamentals Vol. Vol. E88-A ( No. 1 ) page： 25-32 2005.1

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

OMAC is a provably secure MAC scheme proposed by Iwata and Kurosawa. In August 2003, Mitchell published a note "On the security of XCBC, TMAC and OMAC" to propose a new variant of OMAC, which we call OMAC1". In this paper, we prove that OMAC1" is less secure than the original OMAC. We show a security gap between them. As a result, we obtain a negative answer to Mitchell's open question, i.e., OMAC1" is not provably secure even if the underlying block cipher is a PRP.

DOI： 10.1093/ietfec/E88-A.1.25

How to re-use round function in super-pseudorandom permutation Reviewed

Tetsu Iwata and Kaoru Kurosawa

The 9th Australasian Conference on Information Security and Privacy, ACISP 2004, Lecture Notes in Computer Science, Springer ( LNCS 3108 ) page： 224-235 2004.6

On the correctness of security proofs for the 3GPP confidentiality and integrity algorithms Reviewed

Tetsu Iwata and Kaoru Kurosawa

IEICE Trans. Fundamentals Vol. Vol. E87-A ( No. 5 ) page： 1110-1118 2004.5

On the pseudorandomness of KASUMI type permutations Reviewed

Tetsu Iwata, Tohru Yagi and Kaoru Kurosawa

IEICE Trans. Fundamentals Vol. Vol. E87-A ( No. 5 ) page： 1098-1109 2004.5

New covering radius of Reed-Muller codes for t-resilient functions Reviewed

Kaoru Kurosawa, Tetsu Iwata and Takayuki Yoshiwara

IEEE Trans. Inform. Theory Vol. Vol. 50 ( No. 3 ) page： 468-475 2004.3

New security proofs for the 3GPP confidentiality and integrity algorithms Reviewed

Tetsu Iwata and Tadayoshi Kohno

Fast Software Encryption, FSE 2004, Lecture Notes in Computer Science, Springer ( LNCS 3017 ) page： 427-445 2004.2

On the universal hash functions in Luby-Rackoff cipher Reviewed

Tetsu Iwata and Kaoru Kurosawa

IEICE Trans. Fundamentals Vol. Vol. E87-A ( No. 1 ) page： 60-66 2004.1

TMAC: Two-Key CBC MAC Reviewed

Kaoru Kurosawa and Tetsu Iwata

IEICE Trans. Fundamentals Vol. Vol. E87-A ( No. 1 ) page： 46-53 2004.1

Stronger security bounds for OMAC, TMAC and XCBC Reviewed

Tetsu Iwata and Kaoru Kurosawa

Progress in Cryptology, INDOCRYPT 2003, Lecture Notes in Computer Science, Springer ( LNCS 2904 ) page： 402-415 2003.12

Authorship：Lead author Language：English

OMAC, TMAC and XCBC are CBC-type MAC schemes which are provably secure for arbitrary message length. In this paper, we present a more tight upper bound on Adv for each scheme, where Adv denotes the maximum success (forgery) probability of adversaries. Our bounds are expressed in terms of the total length of all queries of an adversary to the MAC generation oracle while the previous bounds are expressed in terms of the maximum length of each query. In particular, a significant improvement occurs if the lengths of queries are heavily unbalanced.

On the correctness of security proofs for the 3GPP confidentiality and integrity algorithms Reviewed

Tetsu Iwata and Kaoru Kurosawa

Cryptography and Coding, Ninth IMA International Conference, Lecture Notes in Computer Science, Springer ( LNCS 2898 ) page： 427-445 2003.12

On the security of a new variant of OMAC Reviewed

Tetsu Iwata and Kaoru Kurosawa

The 6th Annual International Conference on Information Security and Cryptology, ICISC 2003, Lecture Notes in Computer Science, Springer ( LNCS 2971 ) page： 67-78 2003.11

Non-cryptographic primitive for pseudorandom permutation Reviewed

Tetsu Iwata, Tomonobu Yoshino and Kaoru Kurosawa

Theoretical Computer Science Vol. Vol. 306 ( 1-3 ) page： 139-154 2003.9

On the pseudorandomness of KASUMI type permutations Reviewed

Tetsu Iwata, Tohru Yagi and Kaoru Kurosawa

The 8th Australasian Conference on Information Security and Privacy, ACISP 2003, Lecture Notes in Computer Science, Springer ( LNCS 2727 ) page： 130-141 2003.6

TMAC: Two-Key CBC MAC Reviewed

Kaoru Kurosawa and Tetsu Iwata

Topics in Cryptology, CT-RSA 2003, Lecture Notes in Computer Science, Springer ( LNCS 2612 ) page： 33-49 2003.4

*OMAC: One-Key CBC MAC Reviewed

Tetsu Iwata and Kaoru Kurosawa

Fast Software Encryption, FSE 2003, Lecture Notes in Computer Science, Springer ( LNCS 2887 ) page： 129-153 2003.2

Inclusion relations of Boolean functions satisfying PC(l) of order k Reviewed

Tetsu Iwata and Kaoru Kurosawa

IEICE Trans. Fundamentals Vol. Vol. E86-A ( No. 1 ) page： 47-53 2003.1

On the universal hash functions in Luby-Rackoff cipher Reviewed

Tetsu Iwata and Kaoru Kurosawa

The 5th Annual International Conference on Information Security and Cryptology, ICISC 2002, Lecture Notes in Computer Science, Springer ( LNCS 2578 ) page： 226-236 2002.11

Non-cryptographic primitive for pseudorandom permutation Reviewed

Tetsu Iwata, Tomonobu Yoshino and Kaoru Kurosawa

Fast Software Encryption, FSE 2002, Lecture Notes in Computer Science, Springer ( LNCS 2365 ) page： 149-163 2002.2

Round security and super-pseudorandomness of MISTY type structure Reviewed

Tetsu Iwata, Tomonobu Yoshino, Tomohiro Yuasa and Kaoru Kurosawa

IEICE Trans. Fundamentals Vol. Vol. E85-A ( No. 1 ) page： 2-10 2002.1

New covering radius of Reed-Muller codes for t-resilient functions Reviewed

Tetsu Iwata, Takayuki Yoshiwara and Kaoru Kurosawa

Selected Areas in Cryptography, SAC 2001, Lecture Notes in Computer Science, Springer ( LNCS 2259 ) page： 75-86 2001.8

Round security and super-pseudorandomness of MISTY type structure Reviewed

Tetsu Iwata, Tomonobu Yoshino, Tomohiro Yuasa and Kaoru Kurosawa

Fast Software Encryption, FSE 2001, Lecture Notes in Computer Science, Springer ( LNCS 2355 ) page： 233-247 2001.4

Root finding interpolation attack Reviewed

Kaoru Kurosawa, Tetsu Iwata and Quang Viet Duong

Selected Areas in Cryptography, SAC 2000, Lecture Notes in Computer Science, Springer ( LNCS 2012 ) page： 303-314 2000.8

On the pseudorandomness of the AES finalists --- RC6 and Serpent Reviewed

Tetsu Iwata and Kaoru Kurosawa

Fast Software Encryption, FSE 2000, Lecture Notes in Computer Science, Springer ( LNCS 1978 ) page： 231-243 2000.4

Probabilistic higher order differential attack and higher order bent functions Reviewed

Tetsu Iwata and Kaoru Kurosawa

Advances in Cryptology, ASIACRYPT '99, Lecture Notes in Computer Science, Springer ( LNCS 1716 ) page： 62-74 1999.11

On cryptographically secure vectorial Boolean functions Reviewed

Takashi Satoh, Tetsu Iwata and Kaoru Kurosawa

Advances in Cryptology, ASIACRYPT '99, Lecture Notes in Computer Science, Springer ( LNCS 1716 ) page： 20-28 1999.11

Inclusion relations of Boolean functions satisfying PC(l) of order k Reviewed

Tetsu Iwata and Kaoru Kurosawa

Sequences and Their Applications, SETA '98, DMTCS, Springer ( DMTCS ) page： 263-272 1998.12

Balanced Boolean functions satisfying PC(2) and very large degree Reviewed

Tomoyoshi Honda, Takashi Satoh, Tetsu Iwata and Kaoru Kurosawa

Proceedings of the Fourth Annual Workshop on Selected Areas in Cryptography, SAC '97 page： 64-72 1997.8

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