論文

2026

1. IACR CiC

   Generalizing Bit-based Rebound Attacks on AES-like Hashing

   Kodai Taiyama , Ryoma Ito , Kosei Sakamoto , Kazuma Taka , Keita Toyama , and Takanori Isobe

   IACR Communications in Cryptology, 2026

   DOI Bib

   @article{DBLP:journals/cic/TaiyamaISTTI26,
     author = {Taiyama, Kodai and Ito, Ryoma and Sakamoto, Kosei and Taka, Kazuma and Toyama, Keita and Isobe, Takanori},
     title = {Generalizing Bit-based Rebound Attacks on {AES}-like Hashing},
     volume = {3},
     number = {3},
     year = {2026},
     date = {2026-10-26},
     issn = {3006-5496},
     doi = {10.62056/a6y7n5qiu},
     journal = {{IACR} Communications in Cryptology},
     publisher = {International Association for Cryptologic Research}
   }

2025

1. IACR CiC

   Exploring SHA Instructions and Its Application to AES-based Schemes

   Takuro Shiraya , Subhadeep Banik , Tatsuya Ishikawa , Ryoma Ito , Mostafizar Rahman , Kosei Sakamoto , Atsushi Tanaka , Shion Utsumi , and Takanori Isobe

   IACR Commun. Cryptol., 2025

   DOI Bib Code

   @article{DBLP:journals/cic/ShirayaBIIRSTUI25,
     author = {Shiraya, Takuro and Banik, Subhadeep and Ishikawa, Tatsuya and Ito, Ryoma and Rahman, Mostafizar and Sakamoto, Kosei and Tanaka, Atsushi and Utsumi, Shion and Isobe, Takanori},
     title = {Exploring {SHA} Instructions and Its Application to AES-based Schemes},
     journal = {{IACR} Commun. Cryptol.},
     volume = {2},
     number = {3},
     pages = {28},
     year = {2025},
     url = {https://doi.org/10.62056/anxrudy6b},
     doi = {10.62056/ANXRUDY6B},
     timestamp = {Sat, 12 Sep 2026 15:34:09 +0200},
     biburl = {https://dblp.org/rec/journals/cic/ShirayaBIIRSTUI25.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. JISA

   Security analysis of SFrame

   Takanori Isobe , Ryoma Ito , and Kazuhiko Minematsu

   J. Inf. Secur. Appl., 2025

   DOI Bib

   @article{DBLP:journals/istr/IsobeIM25,
     author = {Isobe, Takanori and Ito, Ryoma and Minematsu, Kazuhiko},
     title = {Security analysis of SFrame},
     journal = {J. Inf. Secur. Appl.},
     volume = {89},
     pages = {103958},
     year = {2025},
     url = {https://doi.org/10.1016/j.jisa.2024.103958},
     doi = {10.1016/J.JISA.2024.103958},
     timestamp = {Fri, 14 Feb 2025 20:50:10 +0100},
     biburl = {https://dblp.org/rec/journals/istr/IsobeIM25.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

3. JISA

   On the effects of neural network-based output prediction attacks on the design of symmetric-key ciphers

   Hayato Watanabe , Ryoma Ito , and Toshihiro Ohigashi

   J. Inf. Secur. Appl., 2025

   DOI Bib

   @article{DBLP:journals/istr/WatanabeIO25,
     author = {Watanabe, Hayato and Ito, Ryoma and Ohigashi, Toshihiro},
     title = {On the effects of neural network-based output prediction attacks on
                       the design of symmetric-key ciphers},
     journal = {J. Inf. Secur. Appl.},
     volume = {90},
     pages = {104016},
     year = {2025},
     url = {https://doi.org/10.1016/j.jisa.2025.104016},
     doi = {10.1016/J.JISA.2025.104016},
     timestamp = {Tue, 01 Apr 2025 19:01:51 +0200},
     biburl = {https://dblp.org/rec/journals/istr/WatanabeIO25.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

4. JISA

   Parallel SAT framework to find clustering of differential characteristics and its applications

   Kosei Sakamoto , Ryoma Ito , and Takanori Isobe

   J. Inf. Secur. Appl., 2025

   DOI Bib

   @article{DBLP:journals/istr/SakamotoII25,
     author = {Sakamoto, Kosei and Ito, Ryoma and Isobe, Takanori},
     title = {Parallel {SAT} framework to find clustering of differential characteristics
                       and its applications},
     journal = {J. Inf. Secur. Appl.},
     volume = {94},
     pages = {104203},
     year = {2025},
     url = {https://doi.org/10.1016/j.jisa.2025.104203},
     doi = {10.1016/J.JISA.2025.104203},
     timestamp = {Sun, 02 Nov 2025 12:35:07 +0100},
     biburl = {https://dblp.org/rec/journals/istr/SakamotoII25.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

5. IACR ToSC

   Divide-and-Conquer SAT for Exploring Optimal Differential and Linear Characteristics and Its Applications

   Kazuma Taka , Kosei Sakamoto , Ryoma Ito , Rentaro Shiba , Shion Utsumi , and Takanori Isobe

   IACR Trans. Symmetric Cryptol., 2025

   DOI Bib Code Slides

   @article{DBLP:journals/tosc/TakaSISUI25,
     author = {Taka, Kazuma and Sakamoto, Kosei and Ito, Ryoma and Shiba, Rentaro and Utsumi, Shion and Isobe, Takanori},
     title = {Divide-and-Conquer {SAT} for Exploring Optimal Differential and Linear
                       Characteristics and Its Applications},
     journal = {{IACR} Trans. Symmetric Cryptol.},
     volume = {2025},
     number = {3},
     pages = {516--576},
     year = {2025},
     url = {https://doi.org/10.46586/tosc.v2025.i3.516-576},
     doi = {10.46586/TOSC.V2025.I3.516-576},
     timestamp = {Sat, 15 Nov 2025 13:54:58 +0100},
     biburl = {https://dblp.org/rec/journals/tosc/TakaSISUI25.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

6. IACR ToSC

   Dialga: A Family of Low-Latency Tweakable Block Ciphers Using Multiple Linear Layers

   Subhadeep Banik , Tatsuya Ishikawa , Takanori Isobe , Ryoma Ito , Kazuhiko Minematsu , Kazuma Nakata , Mostafizar Rahman , and Kosei Sakamoto

   IACR Trans. Symmetric Cryptol., 2025

   DOI Bib Slides

   @article{DBLP:journals/tosc/BanikIIIMNRS25,
     author = {Banik, Subhadeep and Ishikawa, Tatsuya and Isobe, Takanori and Ito, Ryoma and Minematsu, Kazuhiko and Nakata, Kazuma and Rahman, Mostafizar and Sakamoto, Kosei},
     title = {Dialga: {A} Family of Low-Latency Tweakable Block Ciphers Using Multiple
                       Linear Layers},
     journal = {{IACR} Trans. Symmetric Cryptol.},
     volume = {2025},
     number = {4},
     pages = {70--124},
     year = {2025},
     url = {https://doi.org/10.46586/tosc.v2025.i4.70-124},
     doi = {10.46586/TOSC.V2025.I4.70-124},
     timestamp = {Sat, 12 Sep 2026 15:36:30 +0200},
     biburl = {https://dblp.org/rec/journals/tosc/BanikIIIMNRS25.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2023

1. IEICE Trans.

   PNB Based Differential Cryptanalysis of Salsa20 and ChaCha

   Nasratullah Ghafoori , Atsuko Miyaji , Ryoma Ito , and Shotaro Miyashita

   IEICE Trans. Inf. Syst., 2023

   DOI Bib

   @article{DBLP:journals/ieicetd/GhafooriMIM23,
     author = {Ghafoori, Nasratullah and Miyaji, Atsuko and Ito, Ryoma and Miyashita, Shotaro},
     title = {{PNB} Based Differential Cryptanalysis of Salsa20 and ChaCha},
     journal = {{IEICE} Trans. Inf. Syst.},
     volume = {106},
     number = {9},
     pages = {1407--1422},
     year = {2023},
     url = {https://doi.org/10.1587/transinf.2022icp0015},
     doi = {10.1587/TRANSINF.2022ICP0015},
     timestamp = {Sat, 15 Nov 2025 13:52:16 +0100},
     biburl = {https://dblp.org/rec/journals/ieicetd/GhafooriMIM23.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. IPSJ JIP

   Cryptanalysis on End-to-End Encryption Schemes of Communication Tools and Its Research Trend

   Takanori Isobe , Ryoma Ito , and Kazuhiko Minematsu

   J. Inf. Process., 2023

   DOI Bib

   @article{DBLP:journals/jip/IsobeIM23,
     author = {Isobe, Takanori and Ito, Ryoma and Minematsu, Kazuhiko},
     title = {Cryptanalysis on End-to-End Encryption Schemes of Communication Tools
                       and Its Research Trend},
     journal = {J. Inf. Process.},
     volume = {31},
     pages = {523--536},
     year = {2023},
     url = {https://doi.org/10.2197/ipsjjip.31.523},
     doi = {10.2197/IPSJJIP.31.523},
     timestamp = {Sat, 28 Oct 2023 13:59:25 +0200},
     biburl = {https://dblp.org/rec/journals/jip/IsobeIM23.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

3. IPSJ JIP

   A Deeper Look into Deep Learning-based Output Prediction Attacks Using Weak SPN Block Ciphers

   Hayato Kimura , Keita Emura , Takanori Isobe , Ryoma Ito , Kazuto Ogawa , and Toshihiro Ohigashi

   J. Inf. Process., 2023

   DOI Bib

   @article{DBLP:journals/jip/KimuraEIIOO23,
     author = {Kimura, Hayato and Emura, Keita and Isobe, Takanori and Ito, Ryoma and Ogawa, Kazuto and Ohigashi, Toshihiro},
     title = {A Deeper Look into Deep Learning-based Output Prediction Attacks Using
                       Weak {SPN} Block Ciphers},
     journal = {J. Inf. Process.},
     volume = {31},
     pages = {550--561},
     year = {2023},
     url = {https://doi.org/10.2197/ipsjjip.31.550},
     doi = {10.2197/IPSJJIP.31.550},
     timestamp = {Sat, 28 Oct 2023 13:59:25 +0200},
     biburl = {https://dblp.org/rec/journals/jip/KimuraEIIOO23.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

4. IACR TCHES

   Areion: Highly-Efficient Permutations and Its Applications to Hash Functions for Short Input

   Takanori Isobe , Ryoma Ito , Fukang Liu , Kazuhiko Minematsu , Motoki Nakahashi , Kosei Sakamoto , and Rentaro Shiba

   IACR Trans. Cryptogr. Hardw. Embed. Syst., 2023

   DOI Bib Code Slides

   @article{DBLP:journals/tches/IsobeILMNSS23,
     author = {Isobe, Takanori and Ito, Ryoma and Liu, Fukang and Minematsu, Kazuhiko and Nakahashi, Motoki and Sakamoto, Kosei and Shiba, Rentaro},
     title = {Areion: Highly-Efficient Permutations and Its Applications to Hash
                       Functions for Short Input},
     journal = {{IACR} Trans. Cryptogr. Hardw. Embed. Syst.},
     volume = {2023},
     number = {2},
     pages = {115--154},
     year = {2023},
     url = {https://doi.org/10.46586/tches.v2023.i2.115-154},
     doi = {10.46586/TCHES.V2023.I2.115-154},
     timestamp = {Mon, 26 Jun 2023 20:57:37 +0200},
     biburl = {https://dblp.org/rec/journals/tches/IsobeILMNSS23.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

5. IACR ToSC

   Key Committing Security of AEZ and More

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

   IACR Trans. Symmetric Cryptol., 2023

   DOI Bib Slides

   @article{DBLP:journals/tosc/ChenFIIIMMNST23,
     author = {Chen, Yu Long and Fl{\'{o}}rez{-}Guti{\'{e}}rrez, Antonio and Inoue, Akiko and Ito, Ryoma and Iwata, Tetsu and Minematsu, Kazuhiko and Mouha, Nicky and Naito, Yusuke and Sibleyras, Ferdinand and Todo, Yosuke},
     title = {Key Committing Security of {AEZ} and More},
     journal = {{IACR} Trans. Symmetric Cryptol.},
     volume = {2023},
     number = {4},
     pages = {452--488},
     year = {2023},
     url = {https://doi.org/10.46586/tosc.v2023.i4.452-488},
     doi = {10.46586/TOSC.V2023.I4.452-488},
     timestamp = {Mon, 05 Feb 2024 20:25:42 +0100},
     biburl = {https://dblp.org/rec/journals/tosc/ChenFIIIMMNST23.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2022

1. IACR ToSC

   Distinguishing and key recovery attacks on the reduced-round SNOW-V and SNOW-Vi

   Jin Hoki , Takanori Isobe , Ryoma Ito , Fukang Liu , and Kosei Sakamoto

   J. Inf. Secur. Appl., 2022

   DOI Bib

   @article{DBLP:journals/istr/HokiIILS22,
     author = {Hoki, Jin and Isobe, Takanori and Ito, Ryoma and Liu, Fukang and Sakamoto, Kosei},
     title = {Distinguishing and key recovery attacks on the reduced-round {SNOW-V}
                       and SNOW-Vi},
     journal = {J. Inf. Secur. Appl.},
     volume = {65},
     pages = {103100},
     year = {2022},
     url = {https://doi.org/10.1016/j.jisa.2021.103100},
     doi = {10.1016/J.JISA.2021.103100},
     timestamp = {Fri, 13 May 2022 19:52:43 +0200},
     biburl = {https://dblp.org/rec/journals/istr/HokiIILS22.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. IACR ToSC

   Cryptanalysis of Rocca and Feasibility of Its Security Claim

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

   IACR Trans. Symmetric Cryptol., 2022

   DOI Bib Code Slides

   @article{DBLP:journals/tosc/HosoyamadaIIIMS22,
     author = {Hosoyamada, Akinori and Inoue, Akiko and Ito, Ryoma and Iwata, Tetsu and Minematsu, Kazuhiko and Sibleyras, Ferdinand and Todo, Yosuke},
     title = {Cryptanalysis of Rocca and Feasibility of Its Security Claim},
     journal = {{IACR} Trans. Symmetric Cryptol.},
     volume = {2022},
     number = {3},
     pages = {123--151},
     year = {2022},
     url = {https://doi.org/10.46586/tosc.v2022.i3.123-151},
     doi = {10.46586/TOSC.V2022.I3.123-151},
     timestamp = {Fri, 05 May 2023 06:50:42 +0200},
     biburl = {https://dblp.org/rec/journals/tosc/HosoyamadaIIIMS22.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

3. IACR ToSC

   New Cryptanalysis of ZUC-256 Initialization Using Modular Differences

   Fukang Liu , Willi Meier , Santanu Sarkar , Gaoli Wang , Ryoma Ito , and Takanori Isobe

   IACR Trans. Symmetric Cryptol., 2022

   DOI Bib Code Slides

   @article{DBLP:journals/tosc/LiuMSWII22,
     author = {Liu, Fukang and Meier, Willi and Sarkar, Santanu and Wang, Gaoli and Ito, Ryoma and Isobe, Takanori},
     title = {New Cryptanalysis of {ZUC-256} Initialization Using Modular Differences},
     journal = {{IACR} Trans. Symmetric Cryptol.},
     volume = {2022},
     number = {3},
     pages = {152--190},
     year = {2022},
     url = {https://doi.org/10.46586/tosc.v2022.i3.152-190},
     doi = {10.46586/TOSC.V2022.I3.152-190},
     timestamp = {Tue, 06 Dec 2022 13:15:32 +0100},
     biburl = {https://dblp.org/rec/journals/tosc/LiuMSWII22.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2021

1. IEEE Access

   Security Analysis of End-to-End Encryption for Zoom Meetings

   Takanori Isobe and Ryoma Ito

   IEEE Access, 2021

   DOI Bib

   @article{DBLP:journals/access/IsobeI21,
     author = {Isobe, Takanori and Ito, Ryoma},
     title = {Security Analysis of End-to-End Encryption for Zoom Meetings},
     journal = {{IEEE} Access},
     volume = {9},
     pages = {90677--90689},
     year = {2021},
     url = {https://doi.org/10.1109/ACCESS.2021.3091722},
     doi = {10.1109/ACCESS.2021.3091722},
     timestamp = {Mon, 28 Aug 2023 21:20:20 +0200},
     biburl = {https://dblp.org/rec/journals/access/IsobeI21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. IEICE Trans.

   New Iterated RC4 Key Correlations and their Application to Plaintext Recovery on WPA-TKIP

   Ryoma Ito and Atsuko Miyaji

   IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2021

   DOI Bib

   @article{DBLP:journals/ieiceta/ItoM21,
     author = {Ito, Ryoma and Miyaji, Atsuko},
     title = {New Iterated {RC4} Key Correlations and their Application to Plaintext
                       Recovery on {WPA-TKIP}},
     journal = {{IEICE} Trans. Fundam. Electron. Commun. Comput. Sci.},
     volume = {104-A},
     number = {1},
     pages = {190--202},
     year = {2021},
     url = {https://doi.org/10.1587/transfun.2020CIP0006},
     doi = {10.1587/TRANSFUN.2020CIP0006},
     timestamp = {Tue, 07 May 2024 20:20:15 +0200},
     biburl = {https://dblp.org/rec/journals/ieiceta/ItoM21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

3. JISA

   Bit-wise cryptanalysis on AND-RX permutation Friet-PC

   Ryoma Ito , Rentaro Shiba , Kosei Sakamoto , Fukang Liu , and Takanori Isobe

   J. Inf. Secur. Appl., 2021

   DOI Bib

   @article{DBLP:journals/istr/ItoSSLI21,
     author = {Ito, Ryoma and Shiba, Rentaro and Sakamoto, Kosei and Liu, Fukang and Isobe, Takanori},
     title = {Bit-wise cryptanalysis on {AND-RX} permutation Friet-PC},
     journal = {J. Inf. Secur. Appl.},
     volume = {59},
     pages = {102860},
     year = {2021},
     url = {https://doi.org/10.1016/j.jisa.2021.102860},
     doi = {10.1016/J.JISA.2021.102860},
     timestamp = {Sat, 09 Apr 2022 12:25:36 +0200},
     biburl = {https://dblp.org/rec/journals/istr/ItoSSLI21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2017

1. IEICE Trans.

   Refined Construction of RC4 Key Setting in WPA

   Ryoma Ito and Atsuko Miyaji

   IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2017

   DOI Bib

   @article{DBLP:journals/ieicet/ItoM17,
     author = {Ito, Ryoma and Miyaji, Atsuko},
     title = {Refined Construction of {RC4} Key Setting in {WPA}},
     journal = {{IEICE} Trans. Fundam. Electron. Commun. Comput. Sci.},
     volume = {100-A},
     number = {1},
     pages = {138--148},
     year = {2017},
     url = {https://doi.org/10.1587/transfun.E100.A.138},
     doi = {10.1587/TRANSFUN.E100.A.138},
     timestamp = {Tue, 07 May 2024 20:14:21 +0200},
     biburl = {https://dblp.org/rec/journals/ieicet/ItoM17.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2016

1. IEICE Trans.

   Refined Glimpse Correlations of RC4

   Ryoma Ito and Atsuko Miyaji

   IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2016

   DOI Bib

   @article{DBLP:journals/ieicet/ItoM16,
     author = {Ito, Ryoma and Miyaji, Atsuko},
     title = {Refined Glimpse Correlations of {RC4}},
     journal = {{IEICE} Trans. Fundam. Electron. Commun. Comput. Sci.},
     volume = {99-A},
     number = {1},
     pages = {3--13},
     year = {2016},
     url = {https://doi.org/10.1587/transfun.E99.A.3},
     doi = {10.1587/TRANSFUN.E99.A.3},
     timestamp = {Tue, 07 May 2024 20:14:21 +0200},
     biburl = {https://dblp.org/rec/journals/ieicet/ItoM16.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. IEICE Trans.

   Refined RC4 Key Correlations of Internal States in WPA

   Ryoma Ito and Atsuko Miyaji

   IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2016

   DOI Bib

   @article{DBLP:journals/ieicet/ItoM16a,
     author = {Ito, Ryoma and Miyaji, Atsuko},
     title = {Refined {RC4} Key Correlations of Internal States in {WPA}},
     journal = {{IEICE} Trans. Fundam. Electron. Commun. Comput. Sci.},
     volume = {99-A},
     number = {6},
     pages = {1132--1144},
     year = {2016},
     url = {https://doi.org/10.1587/transfun.E99.A.1132},
     doi = {10.1587/TRANSFUN.E99.A.1132},
     timestamp = {Tue, 07 May 2024 20:14:25 +0200},
     biburl = {https://dblp.org/rec/journals/ieicet/ItoM16a.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2026

1. ASIACRYPT

   Finding Collision for HMAC-SHA Forgery in the Secret-State Setting

   Tatsuya Ishikawa , Takanori Isobe , Ryoma Ito , Kosei Sakamoto , Kosuke Sasaki , Kazuma Taka , and Shion Utsumi

   In Advances in Cryptology - ASIACRYPT 2026 - 32th International Conference on the Theory and Application of Cryptology and Information Security (to appear), 2026

   DOI
2. CANS

   Accelerated Differential Search for Gleeok Using Hamming-Weight-Guided SAT Solving

   Kento Morita , Tatsuya Ishikawa , Takuro Shiraya , Kosei Sakamoto , Ryoma Ito , and Takanori Isobe

   In International Conference on Cryptology and Network Security, CANS 2026 (to appear), 2026

   DOI
3. ISITA

   Refining the Evaluation of Diffusion Property for Simon Variants

   Kota Tatsumi , Hayato Watanabe , Ryoma Ito , and Toshihiro Ohigashi

   In International Symposium on Information Theory and Its Applications, ISITA 2026 (to appear), 2026

   DOI
4. ACISP

   Automated Tool for Finding Practical Collisions on SPN-Based Hash Functions

   Keita Toyama , Kosei Sakamoto , Ryoma Ito , Kazuma Taka , Kodai Taiyama , and Takanori Isobe

   In Information Security and Privacy - 31st Australasian Conference, ACISP 2026, Perth, WA, Australia, July 6-9, 2026, Proceedings, Part I, 2026 採択率: 26.5% (69/260)

   DOI Bib

   @inproceedings{DBLP:conf/acisp/ToyamaSITTI26,
     author = {Toyama, Keita and Sakamoto, Kosei and Ito, Ryoma and Taka, Kazuma and Taiyama, Kodai and Isobe, Takanori},
     editor = {Ma, Siqi and Nepal, Surya},
     title = {Automated Tool for Finding Practical Collisions on SPN-Based Hash
                       Functions},
     booktitle = {Information Security and Privacy - 31st Australasian Conference, {ACISP}
                       2026, Perth, WA, Australia, July 6-9, 2026, Proceedings, Part {I}},
     series = {Lecture Notes in Computer Science},
     volume = {16792},
     pages = {3--39},
     publisher = {Springer},
     year = {2026},
     url = {https://doi.org/10.1007/978-981-92-3012-9\_1},
     doi = {10.1007/978-981-92-3012-9\_1},
     timestamp = {Mon, 03 Aug 2026 20:40:23 +0200},
     biburl = {https://dblp.org/rec/conf/acisp/ToyamaSITTI26.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

5. ACISP

   Analyzing Forgery Security of LeMac: Tight Bounds and Impact of Padding

   Taichi Nagoya , Takuro Shiraya , Kazuma Taka , Tatsuya Ishikawa , Kosei Sakamoto , Ryoma Ito , and Takanori Isobe

   In Information Security and Privacy - 31st Australasian Conference, ACISP 2026, Perth, WA, Australia, July 6-9, 2026, Proceedings, Part I, 2026 採択率: 26.5% (69/260)

   DOI Bib

   @inproceedings{DBLP:conf/acisp/NagoyaSTISII26,
     author = {Nagoya, Taichi and Shiraya, Takuro and Taka, Kazuma and Ishikawa, Tatsuya and Sakamoto, Kosei and Ito, Ryoma and Isobe, Takanori},
     editor = {Ma, Siqi and Nepal, Surya},
     title = {Analyzing Forgery Security of LeMac: Tight Bounds and Impact of Padding},
     booktitle = {Information Security and Privacy - 31st Australasian Conference, {ACISP}
                       2026, Perth, WA, Australia, July 6-9, 2026, Proceedings, Part {I}},
     series = {Lecture Notes in Computer Science},
     volume = {16792},
     pages = {79--101},
     publisher = {Springer},
     year = {2026},
     url = {https://doi.org/10.1007/978-981-92-3012-9\_4},
     doi = {10.1007/978-981-92-3012-9\_4},
     timestamp = {Mon, 03 Aug 2026 20:40:23 +0200},
     biburl = {https://dblp.org/rec/conf/acisp/NagoyaSTISII26.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2025

1. ACSAC

   Gravity of the Situation: Security Analysis on Rocket.Chat E2EE

   Hayato Kimura , Ryoma Ito , Kazuhiko Minematsu , and Takanori Isobe

   In IEEE Annual Computer Security Applications Conference, ACSAC 2025, Honolulu, HI, USA, December 8-12, 2025, 2025 採択率: 20.7% (84/406)

   DOI Bib Code Slides Website

   @inproceedings{DBLP:conf/acsac/KimuraIMI25,
     author = {Kimura, Hayato and Ito, Ryoma and Minematsu, Kazuhiko and Isobe, Takanori},
     title = {Gravity of the Situation: Security Analysis on Rocket.Chat {E2EE}},
     booktitle = {{IEEE} Annual Computer Security Applications Conference, {ACSAC} 2025,
                       Honolulu, HI, USA, December 8-12, 2025},
     pages = {15--30},
     publisher = {{IEEE}},
     year = {2025},
     url = {https://doi.org/10.1109/ACSAC67867.2025.00018},
     doi = {10.1109/ACSAC67867.2025.00018},
     timestamp = {Sun, 21 Jun 2026 17:17:38 +0200},
     biburl = {https://dblp.org/rec/conf/acsac/KimuraIMI25.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. EuroS&P

   Not in The Prophecies: Practical Attacks on Nostr

   Hayato Kimura , Ryoma Ito , Kazuhiko Minematsu , Shogo Shiraki , and Takanori Isobe

   In 10th IEEE European Symposium on Security and Privacy, EuroS&P 2025, Venice, Italy, June 30 - July 4, 2025, 2025 採択率: 21.9% (60/273)

   DOI Bib Code Website

   @inproceedings{DBLP:conf/eurosp/KimuraIMSI25,
     author = {Kimura, Hayato and Ito, Ryoma and Minematsu, Kazuhiko and Shiraki, Shogo and Isobe, Takanori},
     title = {Not in The Prophecies: Practical Attacks on Nostr},
     booktitle = {10th {IEEE} European Symposium on Security and Privacy, EuroS{\&}P
                       2025, Venice, Italy, June 30 - July 4, 2025},
     pages = {585--606},
     publisher = {{IEEE}},
     year = {2025},
     url = {https://doi.org/10.1109/EuroSP63326.2025.00040},
     doi = {10.1109/EUROSP63326.2025.00040},
     timestamp = {Tue, 14 Oct 2025 19:35:20 +0200},
     biburl = {https://dblp.org/rec/conf/eurosp/KimuraIMSI25.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

3. ICISC

   Comprehensive Security Analysis of End-to-End Encryption in LINE

   Takehiro Matsumoto , Atsushi Tanaka , Kyosuke Yamashita , Ryoma Ito , and Takanori Isobe

   In Information Security and Cryptology - ICISC 2025 - 28th International Conference, Seoul, South Korea, November 19-21, 2025, Revised Selected Papers, 2025 採択率: 37.8% (28/74)

   DOI Bib

   @inproceedings{DBLP:conf/icisc/MatsumotoTYII25,
     author = {Matsumoto, Takehiro and Tanaka, Atsushi and Yamashita, Kyosuke and Ito, Ryoma and Isobe, Takanori},
     editor = {Seo, Hwajeong},
     title = {Comprehensive Security Analysis of End-to-End Encryption in {LINE}},
     booktitle = {Information Security and Cryptology - {ICISC} 2025 - 28th International
                       Conference, Seoul, South Korea, November 19-21, 2025, Revised Selected
                       Papers},
     series = {Lecture Notes in Computer Science},
     volume = {16487},
     pages = {237--256},
     publisher = {Springer},
     year = {2025},
     url = {https://doi.org/10.1007/978-981-95-8034-7\_13},
     doi = {10.1007/978-981-95-8034-7\_13},
     timestamp = {Sun, 21 Jun 2026 17:19:16 +0200},
     biburl = {https://dblp.org/rec/conf/icisc/MatsumotoTYII25.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2024

1. ASIACRYPT

   Key Collisions on AES and Its Applications

   Kodai Taiyama , Kosei Sakamoto , Ryoma Ito , Kazuma Taka , and Takanori Isobe

   In Advances in Cryptology - ASIACRYPT 2024 - 30th International Conference on the Theory and Application of Cryptology and Information Security, Kolkata, India, December 9-13, 2024, Proceedings, Part VII, 2024 採択率: 29.2% (127/435)

   DOI Bib Slides

   @inproceedings{DBLP:conf/asiacrypt/TaiyamaSITI24,
     author = {Taiyama, Kodai and Sakamoto, Kosei and Ito, Ryoma and Taka, Kazuma and Isobe, Takanori},
     editor = {Chung, Kai{-}Min and Sasaki, Yu},
     title = {Key Collisions on {AES} and Its Applications},
     booktitle = {Advances in Cryptology - {ASIACRYPT} 2024 - 30th International Conference
                       on the Theory and Application of Cryptology and Information Security,
                       Kolkata, India, December 9-13, 2024, Proceedings, Part {VII}},
     series = {Lecture Notes in Computer Science},
     volume = {15490},
     pages = {267--300},
     publisher = {Springer},
     year = {2024},
     url = {https://doi.org/10.1007/978-981-96-0941-3\_9},
     doi = {10.1007/978-981-96-0941-3\_9},
     timestamp = {Tue, 21 Apr 2026 08:16:24 +0200},
     biburl = {https://dblp.org/rec/conf/asiacrypt/TaiyamaSITI24.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. CSCML

   On the Effects of Neural Network-Based Output Prediction Attacks on the Design of Symmetric-Key Ciphers

   Hayato Watanabe , Ryoma Ito , and Toshihiro Ohigashi

   In Cyber Security, Cryptology, and Machine Learning - 8th International Symposium, CSCML 2024, Be’er Sheva, Israel, December 19-20, 2024, Proceedings, 2024 採択率: 37.2% (16/43)

   DOI Bib Slides

   @inproceedings{DBLP:conf/cscml/WatanabeIO24,
     author = {Watanabe, Hayato and Ito, Ryoma and Ohigashi, Toshihiro},
     editor = {Dolev, Shlomi and Elhadad, Michael and Kutylowski, Miroslaw and Persiano, Giuseppe},
     title = {On the Effects of Neural Network-Based Output Prediction Attacks on
                       the Design of Symmetric-Key Ciphers},
     booktitle = {Cyber Security, Cryptology, and Machine Learning - 8th International
                       Symposium, {CSCML} 2024, Be'er Sheva, Israel, December 19-20, 2024,
                       Proceedings},
     series = {Lecture Notes in Computer Science},
     volume = {15349},
     pages = {201--218},
     publisher = {Springer},
     year = {2024},
     url = {https://doi.org/10.1007/978-3-031-76934-4\_13},
     doi = {10.1007/978-3-031-76934-4\_13},
     timestamp = {Sat, 25 Jan 2025 23:07:01 +0100},
     biburl = {https://dblp.org/rec/conf/cscml/WatanabeIO24.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2023

1. SAC

   Parallel SAT Framework to Find Clustering of Differential Characteristics and Its Applications

   Kosei Sakamoto , Ryoma Ito , and Takanori Isobe

   In Selected Areas in Cryptography - SAC 2023 - 30th International Conference, Fredericton, Canada, August 14-18, 2023, Revised Selected Papers, 2023 採択率: 43.7% (21/48)

   DOI Bib Slides

   @inproceedings{DBLP:conf/sacrypt/Sakamoto0023,
     author = {Sakamoto, Kosei and Ito, Ryoma and Isobe, Takanori},
     editor = {Carlet, Claude and Mandal, Kalikinkar and Rijmen, Vincent},
     title = {Parallel {SAT} Framework to Find Clustering of Differential Characteristics
                       and Its Applications},
     booktitle = {Selected Areas in Cryptography - {SAC} 2023 - 30th International Conference,
                       Fredericton, Canada, August 14-18, 2023, Revised Selected Papers},
     series = {Lecture Notes in Computer Science},
     volume = {14201},
     pages = {409--428},
     publisher = {Springer},
     year = {2023},
     url = {https://doi.org/10.1007/978-3-031-53368-6\_20},
     doi = {10.1007/978-3-031-53368-6\_20},
     timestamp = {Tue, 07 May 2024 20:12:23 +0200},
     biburl = {https://dblp.org/rec/conf/sacrypt/Sakamoto0023.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2022

1. ACISP

   PNB-Focused Differential Cryptanalysis of ChaCha Stream Cipher

   Shotaro Miyashita , Ryoma Ito , and Atsuko Miyaji

   In Information Security and Privacy - 27th Australasian Conference, ACISP 2022, Wollongong, NSW, Australia, November 28-30, 2022, Proceedings, 2022 採択率: 40.3% (25/62)

   DOI Bib

   @inproceedings{DBLP:conf/acisp/MiyashitaIM22,
     author = {Miyashita, Shotaro and Ito, Ryoma and Miyaji, Atsuko},
     editor = {Nguyen, Khoa and Yang, Guomin and Guo, Fuchun and Susilo, Willy},
     title = {PNB-Focused Differential Cryptanalysis of ChaCha Stream Cipher},
     booktitle = {Information Security and Privacy - 27th Australasian Conference, {ACISP}
                       2022, Wollongong, NSW, Australia, November 28-30, 2022, Proceedings},
     series = {Lecture Notes in Computer Science},
     volume = {13494},
     pages = {46--66},
     publisher = {Springer},
     year = {2022},
     url = {https://doi.org/10.1007/978-3-031-22301-3\_3},
     doi = {10.1007/978-3-031-22301-3\_3},
     timestamp = {Tue, 07 May 2024 20:09:57 +0200},
     biburl = {https://dblp.org/rec/conf/acisp/MiyashitaIM22.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. AIoTS

   Output Prediction Attacks on Block Ciphers Using Deep Learning

   Hayato Kimura , Keita Emura , Takanori Isobe , Ryoma Ito , Kazuto Ogawa , and Toshihiro Ohigashi

   In Applied Cryptography and Network Security Workshops - ACNS 2022 Satellite Workshops, AIBlock, AIHWS, AIoTS, CIMSS, Cloud S&P, SCI, SecMT, SiMLA, Rome, Italy, June 20-23, 2022, Proceedings, 2022 採択率: 59.6% (31/52)

   DOI Bib

   @inproceedings{DBLP:conf/acns/KimuraEIIOO22,
     author = {Kimura, Hayato and Emura, Keita and Isobe, Takanori and Ito, Ryoma and Ogawa, Kazuto and Ohigashi, Toshihiro},
     editor = {Zhou, Jianying and Adepu, Sridhar and Alcaraz, Cristina and Batina, Lejla and Casalicchio, Emiliano and Chattopadhyay, Sudipta and Jin, Chenglu and Lin, Jingqiang and Losiouk, Eleonora and Majumdar, Suryadipta and Meng, Weizhi and Picek, Stjepan and Shao, Jun and Su, Chunhua and Wang, Cong and Zhauniarovich, Yury and Zonouz, Saman A.},
     title = {Output Prediction Attacks on Block Ciphers Using Deep Learning},
     booktitle = {Applied Cryptography and Network Security Workshops - {ACNS} 2022
                       Satellite Workshops, AIBlock, AIHWS, AIoTS, CIMSS, Cloud S{\&}P,
                       SCI, SecMT, SiMLA, Rome, Italy, June 20-23, 2022, Proceedings},
     series = {Lecture Notes in Computer Science},
     volume = {13285},
     pages = {248--276},
     publisher = {Springer},
     year = {2022},
     url = {https://doi.org/10.1007/978-3-031-16815-4\_15},
     doi = {10.1007/978-3-031-16815-4\_15},
     timestamp = {Thu, 06 Feb 2025 08:19:07 +0100},
     biburl = {https://dblp.org/rec/conf/acns/KimuraEIIOO22.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

3. ICEIS

   State-free End-to-End Encrypted Storage and Chat Systems based on Searchable Encryption

   Keita Emura , Ryoma Ito , Sachiko Kanamori , Ryo Nojima , and Yohei Watanabe

   In Proceedings of the 24th International Conference on Enterprise Information Systems, ICEIS 2022, Online Streaming, April 25-27, 2022, Volume 2, 2022 採択率: 32.0% (63/197)

   DOI Bib

   @inproceedings{DBLP:conf/iceis/Emura0KN022,
     author = {Emura, Keita and Ito, Ryoma and Kanamori, Sachiko and Nojima, Ryo and Watanabe, Yohei},
     editor = {Filipe, Joaquim and Smialek, Michal and Brodsky, Alexander and Hammoudi, Slimane},
     title = {State-free End-to-End Encrypted Storage and Chat Systems based on
                       Searchable Encryption},
     booktitle = {Proceedings of the 24th International Conference on Enterprise Information
                       Systems, {ICEIS} 2022, Online Streaming, April 25-27, 2022, Volume
                       2},
     pages = {106--113},
     publisher = {{SCITEPRESS}},
     year = {2022},
     url = {https://doi.org/10.5220/0011045200003179},
     doi = {10.5220/0011045200003179},
     timestamp = {Tue, 06 Jun 2023 14:58:01 +0200},
     biburl = {https://dblp.org/rec/conf/iceis/Emura0KN022.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2021

1. ACISP

   Distinguishing and Key Recovery Attacks on the Reduced-Round SNOW-V

   Jin Hoki , Takanori Isobe , Ryoma Ito , Fukang Liu , and Kosei Sakamoto

   In Information Security and Privacy - 26th Australasian Conference, ACISP 2021, Virtual Event, December 1-3, 2021, Proceedings, 2021 採択率: 22.2% (35/157)

   DOI Bib Slides

   @inproceedings{DBLP:conf/acisp/HokiIILS21,
     author = {Hoki, Jin and Isobe, Takanori and Ito, Ryoma and Liu, Fukang and Sakamoto, Kosei},
     editor = {Baek, Joonsang and Ruj, Sushmita},
     title = {Distinguishing and Key Recovery Attacks on the Reduced-Round {SNOW-V}},
     booktitle = {Information Security and Privacy - 26th Australasian Conference, {ACISP}
                       2021, Virtual Event, December 1-3, 2021, Proceedings},
     series = {Lecture Notes in Computer Science},
     volume = {13083},
     pages = {171--190},
     publisher = {Springer},
     year = {2021},
     url = {https://doi.org/10.1007/978-3-030-90567-5\_9},
     doi = {10.1007/978-3-030-90567-5\_9},
     timestamp = {Mon, 03 Jan 2022 22:39:44 +0100},
     biburl = {https://dblp.org/rec/conf/acisp/HokiIILS21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. ACISP

   Security Analysis of End-to-End Encryption for Zoom Meetings

   Takanori Isobe and Ryoma Ito

   In Information Security and Privacy - 26th Australasian Conference, ACISP 2021, Virtual Event, December 1-3, 2021, Proceedings, 2021 採択率: 22.2% (35/157)

   DOI Bib Slides

   @inproceedings{DBLP:conf/acisp/IsobeI21,
     author = {Isobe, Takanori and Ito, Ryoma},
     editor = {Baek, Joonsang and Ruj, Sushmita},
     title = {Security Analysis of End-to-End Encryption for Zoom Meetings},
     booktitle = {Information Security and Privacy - 26th Australasian Conference, {ACISP}
                       2021, Virtual Event, December 1-3, 2021, Proceedings},
     series = {Lecture Notes in Computer Science},
     volume = {13083},
     pages = {234--253},
     publisher = {Springer},
     year = {2021},
     url = {https://doi.org/10.1007/978-3-030-90567-5\_12},
     doi = {10.1007/978-3-030-90567-5\_12},
     timestamp = {Mon, 03 Jan 2022 22:39:43 +0100},
     biburl = {https://dblp.org/rec/conf/acisp/IsobeI21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

3. ESORICS

   Security Analysis of SFrame

   Takanori Isobe , Ryoma Ito , and Kazuhiko Minematsu

   In Computer Security - ESORICS 2021 - 26th European Symposium on Research in Computer Security, Darmstadt, Germany, October 4-8, 2021, Proceedings, Part II, 2021 採択率: 20.2% (71/351)

   DOI Bib Slides

   @inproceedings{DBLP:conf/esorics/IsobeIM21,
     author = {Isobe, Takanori and Ito, Ryoma and Minematsu, Kazuhiko},
     editor = {Bertino, Elisa and Schulmann, Haya and Waidner, Michael},
     title = {Security Analysis of SFrame},
     booktitle = {Computer Security - {ESORICS} 2021 - 26th European Symposium on Research
                       in Computer Security, Darmstadt, Germany, October 4-8, 2021, Proceedings,
                       Part {II}},
     series = {Lecture Notes in Computer Science},
     volume = {12973},
     pages = {127--146},
     publisher = {Springer},
     year = {2021},
     url = {https://doi.org/10.1007/978-3-030-88428-4\_7},
     doi = {10.1007/978-3-030-88428-4\_7},
     timestamp = {Tue, 17 Oct 2023 10:41:56 +0200},
     biburl = {https://dblp.org/rec/conf/esorics/IsobeIM21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2020

1. ISC

   Rotational Cryptanalysis of Salsa Core Function

   Ryoma Ito

   In Information Security - 23rd International Conference, ISC 2020, Bali, Indonesia, December 16-18, 2020, Proceedings, 2020 採択率: 26.4% (23/87)

   DOI Bib Slides

   @inproceedings{DBLP:conf/isw/Ito20,
     author = {Ito, Ryoma},
     editor = {Susilo, Willy and Deng, Robert H. and Guo, Fuchun and Li, Yannan and Intan, Rolly},
     title = {Rotational Cryptanalysis of Salsa Core Function},
     booktitle = {Information Security - 23rd International Conference, {ISC} 2020,
                       Bali, Indonesia, December 16-18, 2020, Proceedings},
     series = {Lecture Notes in Computer Science},
     volume = {12472},
     pages = {129--145},
     publisher = {Springer},
     year = {2020},
     url = {https://doi.org/10.1007/978-3-030-62974-8\_8},
     doi = {10.1007/978-3-030-62974-8\_8},
     timestamp = {Tue, 10 Feb 2026 15:42:19 +0100},
     biburl = {https://dblp.org/rec/conf/isw/Ito20.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2018

1. ACISP

   New Iterated RC4 Key Correlations

   Ryoma Ito and Atsuko Miyaji

   In Information Security and Privacy - 23rd Australasian Conference, ACISP 2018, Wollongong, NSW, Australia, July 11-13, 2018, Proceedings, 2018 採択率: 30.1% (41/136)

   DOI Bib Slides

   @inproceedings{DBLP:conf/acisp/ItoM18,
     author = {Ito, Ryoma and Miyaji, Atsuko},
     editor = {Susilo, Willy and Yang, Guomin},
     title = {New Iterated {RC4} Key Correlations},
     booktitle = {Information Security and Privacy - 23rd Australasian Conference, {ACISP}
                       2018, Wollongong, NSW, Australia, July 11-13, 2018, Proceedings},
     series = {Lecture Notes in Computer Science},
     volume = {10946},
     pages = {154--171},
     publisher = {Springer},
     year = {2018},
     url = {https://doi.org/10.1007/978-3-319-93638-3\_10},
     doi = {10.1007/978-3-319-93638-3\_10},
     timestamp = {Tue, 07 May 2024 20:09:57 +0200},
     biburl = {https://dblp.org/rec/conf/acisp/ItoM18.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2015

1. ACISP

   How TKIP Induces Biases of Internal States of Generic RC4

   Ryoma Ito and Atsuko Miyaji

   In Information Security and Privacy - 20th Australasian Conference, ACISP 2015, Brisbane, QLD, Australia, June 29 - July 1, 2015, Proceedings, 2015 採択率: 25.0% (28/112)

   DOI Bib Slides

   @inproceedings{DBLP:conf/acisp/ItoM15,
     author = {Ito, Ryoma and Miyaji, Atsuko},
     editor = {Foo, Ernest and Stebila, Douglas},
     title = {How {TKIP} Induces Biases of Internal States of Generic {RC4}},
     booktitle = {Information Security and Privacy - 20th Australasian Conference, {ACISP}
                       2015, Brisbane, QLD, Australia, June 29 - July 1, 2015, Proceedings},
     series = {Lecture Notes in Computer Science},
     volume = {9144},
     pages = {329--342},
     publisher = {Springer},
     year = {2015},
     url = {https://doi.org/10.1007/978-3-319-19962-7\_19},
     doi = {10.1007/978-3-319-19962-7\_19},
     timestamp = {Tue, 07 May 2024 20:09:57 +0200},
     biburl = {https://dblp.org/rec/conf/acisp/ItoM15.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. FSE

   New Linear Correlations Related to State Information of RC4 PRGA Using IV in WPA

   Ryoma Ito and Atsuko Miyaji

   In Fast Software Encryption - 22nd International Workshop, FSE 2015, Istanbul, Turkey, March 8-11, 2015, Revised Selected Papers, 2015 採択率: 39.4% (28/71)

   DOI Bib Slides

   @inproceedings{DBLP:conf/fse/ItoM15,
     author = {Ito, Ryoma and Miyaji, Atsuko},
     editor = {Leander, Gregor},
     title = {New Linear Correlations Related to State Information of {RC4} {PRGA}
                       Using {IV} in {WPA}},
     booktitle = {Fast Software Encryption - 22nd International Workshop, {FSE} 2015,
                       Istanbul, Turkey, March 8-11, 2015, Revised Selected Papers},
     series = {Lecture Notes in Computer Science},
     volume = {9054},
     pages = {557--576},
     publisher = {Springer},
     year = {2015},
     url = {https://doi.org/10.1007/978-3-662-48116-5\_27},
     doi = {10.1007/978-3-662-48116-5\_27},
     timestamp = {Tue, 07 May 2024 20:11:45 +0200},
     biburl = {https://dblp.org/rec/conf/fse/ItoM15.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2014

1. WISA

   New Integrated Long-Term Glimpse of RC4

   Ryoma Ito and Atsuko Miyaji

   In Information Security Applications - 15th International Workshop, WISA 2014, Jeju Island, Korea, August 25-27, 2014. Revised Selected Papers, 2014 採択率: 44.9% (31/69)

   DOI Bib Slides

   @inproceedings{DBLP:conf/wisa/ItoM14,
     author = {Ito, Ryoma and Miyaji, Atsuko},
     editor = {Rhee, Kyung Hyune and Yi, Jeong Hyun},
     title = {New Integrated Long-Term Glimpse of {RC4}},
     booktitle = {Information Security Applications - 15th International Workshop, {WISA}
                       2014, Jeju Island, Korea, August 25-27, 2014. Revised Selected Papers},
     series = {Lecture Notes in Computer Science},
     volume = {8909},
     pages = {137--149},
     publisher = {Springer},
     year = {2014},
     url = {https://doi.org/10.1007/978-3-319-15087-1\_11},
     doi = {10.1007/978-3-319-15087-1\_11},
     timestamp = {Tue, 07 May 2024 20:08:19 +0200},
     biburl = {https://dblp.org/rec/conf/wisa/ItoM14.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2026

1. CSS

   GIFT-128-MMOに対するSATベース実衝突探索の効率化手法

   巽浩太 , 髙和真 , 渡部颯斗 , 松井充 , 伊藤竜馬 , 大東俊博

   コンピュータセキュリティシンポジウム 2026 - CSS 2026, 2026年10月

   3F2-2

   Bib

   @inproceedings{domestic:CSS2026:Tatsumi:3F2-2,
     author = {{巽浩太} and {髙和真} and {渡部颯斗} and {松井充} and {伊藤竜馬} and {大東俊博}},
     title = {{GIFT-128-MMOに対するSATベース実衝突探索の効率化手法}},
     booktitle = {コンピュータセキュリティシンポジウム 2026 - CSS 2026},
     number = {3F2-2},
     note = {3F2-2},
     year = {2026},
     month = oct,
     url = {https://www.iwsec.org/css/2026/program.html#3F2}
   }

2. CSS

   LLM支援によるSATベース衝突探索

   髙和真 , 渡部颯斗 , 伊藤竜馬 , 大東俊博 , 松井充 , 五十部孝典

   コンピュータセキュリティシンポジウム 2026 - CSS 2026, 2026年10月

   2D2-3

   Bib

   @inproceedings{domestic:CSS2026:Taka:2D2-3,
     author = {{髙和真} and {渡部颯斗} and {伊藤竜馬} and {大東俊博} and {松井充} and {五十部孝典}},
     title = {{LLM支援によるSATベース衝突探索}},
     booktitle = {コンピュータセキュリティシンポジウム 2026 - CSS 2026},
     number = {2D2-3},
     note = {2D2-3},
     year = {2026},
     month = oct,
     url = {https://www.iwsec.org/css/2026/program.html#2D2}
   }

3. ISEC

   軽量暗号PRINCEに対する分割クラスタリング手法を用いた差分確率評価

   篠野翼 , 髙和真 , 阪本光星 , 伊藤竜馬 , 五十部孝典

   信学技報, 2026年7月

   ISEC2026-75

   Bib

   @article{domestic:ISEC2026-75,
     author = {{篠野翼} and {髙和真} and {阪本光星} and {伊藤竜馬} and {五十部孝典}},
     title = {{軽量暗号PRINCEに対する分割クラスタリング手法を用いた差分確率評価}},
     journal = {信学技報},
     volume = {126},
     number = {107},
     pages = {440--447},
     note = {ISEC2026-75},
     year = {2026},
     month = jul,
     url = {https://ken.ieice.org/ken/paper/20260715KcWR/}
   }

4. ISEC

   低消費認証暗号AETHERの詳細な安全性評価と改良

   高橋颯 , 川上翔馬 , 石川達也 , 髙和真 , 阪本光星 , 伊藤竜馬 , 五十部孝典

   信学技報, 2026年3月

   ISEC2025-145

   Bib

   @article{domestic:ISEC2025-145,
     author = {{高橋颯} and {川上翔馬} and {石川達也} and {髙和真} and {阪本光星} and {伊藤竜馬} and {五十部孝典}},
     title = {{低消費認証暗号AETHERの詳細な安全性評価と改良}},
     journal = {信学技報},
     volume = {125},
     number = {405},
     pages = {384--391},
     note = {ISEC2025-145},
     year = {2026},
     month = mar,
     url = {https://ken.ieice.org/ken/paper/20260317VctY/}
   }

5. ISEC

   効率的なAESベース認証暗号の設計

   名古屋太一 , 白矢琢朗 , 石川達也 , 阪本光星 , 伊藤竜馬 , Subhadeep Banik , 五十部孝典

   信学技報, 2026年3月

   ISEC2025-144

   Bib

   @article{domestic:ISEC2025-144,
     author = {{名古屋太一} and {白矢琢朗} and {石川達也} and {阪本光星} and {伊藤竜馬} and {Subhadeep Banik} and {五十部孝典}},
     title = {{効率的なAESベース認証暗号の設計}},
     journal = {信学技報},
     volume = {125},
     number = {405},
     pages = {376--383},
     note = {ISEC2025-144},
     year = {2026},
     month = mar,
     url = {https://ken.ieice.org/ken/paper/202603177ctx/}
   }

6. ICSS

   LINEグループ通信に対するTamarin-Proverを用いた安全性自動検証

   松本岳大 , 田中篤 , 山下恭佑 , 伊藤竜馬 , 五十部孝典

   信学技報, 2026年3月

   ICSS2025-86

   Award Bib

   ICSS研究賞

   @article{domestic:ICSS2025-86,
     author = {{松本岳大} and {田中篤} and {山下恭佑} and {伊藤竜馬} and {五十部孝典}},
     title = {{LINEグループ通信に対するTamarin-Proverを用いた安全性自動検証}},
     journal = {信学技報},
     volume = {125},
     number = {381},
     pages = {1--8},
     note = {ICSS2025-86},
     year = {2026},
     month = mar,
     url = {https://ken.ieice.org/ken/paper/20260303Wcsk/},
   }

7. SCIS

   HMAC-SHA-1およびHMAC-SHA-256の衝突を利用した偽造攻撃に対する安全性評価

   佐々木皓亮 , 石川達也 , 内海潮音 , 伊藤竜馬 , 阪本光星 , 五十部孝典

   2026年 暗号と情報セキュリティシンポジウム - SCIS 2026, 2026年1月

   3D3-3

   Bib

   @inproceedings{domestic:SCIS2026:Sasaki:3D3-3,
     author = {{佐々木皓亮} and {石川達也} and {内海潮音} and {伊藤竜馬} and {阪本光星} and {五十部孝典}},
     title = {{HMAC-SHA-1およびHMAC-SHA-256の衝突を利用した偽造攻撃に対する安全性評価}},
     booktitle = {2026年 暗号と情報セキュリティシンポジウム - SCIS 2026},
     number = {3D3-3},
     note = {3D3-3},
     year = {2026},
     month = jan,
     url = {https://www.iwsec.org/scis/2026/program.html#3D3}
   }

8. SCIS

   軽量ハッシュ関数 Lesamnta-LW の衝突攻撃に対する安全性評価

   髙和真 , 伊藤竜馬 , 阪本光星 , 五十部孝典

   2026年 暗号と情報セキュリティシンポジウム - SCIS 2026, 2026年1月

   3D3-2

   Bib

   @inproceedings{domestic:SCIS2026:Taka:3D3-2,
     author = {{髙和真} and {伊藤竜馬} and {阪本光星} and {五十部孝典}},
     title = {{軽量ハッシュ関数 Lesamnta-LW の衝突攻撃に対する安全性評価}},
     booktitle = {2026年 暗号と情報セキュリティシンポジウム - SCIS 2026},
     number = {3D3-2},
     note = {3D3-2},
     year = {2026},
     month = jan,
     url = {https://www.iwsec.org/scis/2026/program.html#3D3}
   }

2025

1. CSS

   LINE Letter Sealingに対するTamarin-Proverを用いた網羅的安全性検証

   松本岳大 , 田中篤 , 山下恭佑 , 伊藤竜馬 , 五十部孝典

   コンピュータセキュリティシンポジウム 2025 - CSS 2025, 2025年10月

   3G3-4

   Bib

   @inproceedings{domestic:CSS2025:Matsumoto:3G3-4,
     author = {{松本岳大} and {田中篤} and {山下恭佑} and {伊藤竜馬} and {五十部孝典}},
     title = {{LINE Letter Sealingに対するTamarin-Proverを用いた網羅的安全性検証}},
     booktitle = {コンピュータセキュリティシンポジウム 2025 - CSS 2025},
     number = {3G3-4},
     note = {3G3-4},
     year = {2025},
     month = oct,
     url = {https://www.iwsec.org/css/2025/program.html#3G3}
   }

2. CSS

   なりすまし攻撃に対するThreemaハンドシェイクプロトコルの形式検証

   中川大輔 , 田中篤 , 木村隼人 , 山下恭佑 , 伊藤竜馬 , 五十部孝典

   コンピュータセキュリティシンポジウム 2025 - CSS 2025, 2025年10月

   3G3-3

   Bib

   @inproceedings{domestic:CSS2025:Nakagawa:3G3-3,
     author = {{中川大輔} and {田中篤} and {木村隼人} and {山下恭佑} and {伊藤竜馬} and {五十部孝典}},
     title = {{なりすまし攻撃に対するThreemaハンドシェイクプロトコルの形式検証}},
     booktitle = {コンピュータセキュリティシンポジウム 2025 - CSS 2025},
     number = {3G3-3},
     note = {3G3-3},
     year = {2025},
     month = oct,
     url = {https://www.iwsec.org/css/2025/program.html#3G3}
   }

3. CSS

   WhatsAppに対する不正デバイス登録攻撃

   白木章伍 , 木村隼人 , 伊藤竜馬 , 峯松一彦 , 五十部孝典

   コンピュータセキュリティシンポジウム 2025 - CSS 2025, 2025年10月

   3G3-2

   Award Bib

   最優秀論文賞

   @inproceedings{domestic:CSS2025:Shiraki:3G3-2,
     author = {{白木章伍} and {木村隼人} and {伊藤竜馬} and {峯松一彦} and {五十部孝典}},
     title = {{WhatsAppに対する不正デバイス登録攻撃}},
     booktitle = {コンピュータセキュリティシンポジウム 2025 - CSS 2025},
     number = {3G3-2},
     note = {3G3-2},
     year = {2025},
     month = oct,
     url = {https://www.iwsec.org/css/2025/program.html#3G3},
   }

4. CSS

   低遅延暗号 Gleeok の差分攻撃に対する安全性評価

   森田健斗 , 石川達也 , 白矢琢朗 , 阪本光星 , 伊藤竜馬 , 五十部孝典

   コンピュータセキュリティシンポジウム 2025 - CSS 2025, 2025年10月

   1G2-4

   Bib

   @inproceedings{domestic:CSS2025:Morita:1G2-4,
     author = {{森田健斗} and {石川達也} and {白矢琢朗} and {阪本光星} and {伊藤竜馬} and {五十部孝典}},
     title = {{低遅延暗号 Gleeok の差分攻撃に対する安全性評価}},
     booktitle = {コンピュータセキュリティシンポジウム 2025 - CSS 2025},
     number = {1G2-4},
     note = {1G2-4},
     year = {2025},
     month = oct,
     url = {https://www.iwsec.org/css/2025/program.html#1G2}
   }

5. CSS

   LeMac-0/LeMacの偽造攻撃に対する安全性評価

   名古屋太一 , 白矢琢朗 , 高和真 , 石川達也 , 阪本光星 , 伊藤竜馬 , 五十部孝典

   コンピュータセキュリティシンポジウム 2025 - CSS 2025, 2025年10月

   1G2-3

   Bib

   @inproceedings{domestic:CSS2025:Nagoya:1G2-3,
     author = {{名古屋太一} and {白矢琢朗} and {高和真} and {石川達也} and {阪本光星} and {伊藤竜馬} and {五十部孝典}},
     title = {{LeMac-0/LeMacの偽造攻撃に対する安全性評価}},
     booktitle = {コンピュータセキュリティシンポジウム 2025 - CSS 2025},
     number = {1G2-3},
     note = {1G2-3},
     year = {2025},
     month = oct,
     url = {https://www.iwsec.org/css/2025/program.html#1G2}
   }

6. CSS

   SHA Extensionsを用いたAES-basedハッシュ関数の拡張

   白矢琢朗 , 石川達也 , 伊藤竜馬 , Mostafizar Rahman , 阪本光星 , 田中篤 , 内海潮音 , 五十部孝典

   コンピュータセキュリティシンポジウム 2025 - CSS 2025, 2025年10月

   1G2-2

   Bib

   @inproceedings{domestic:CSS2025:Shiraya:1G2-2,
     author = {{白矢琢朗} and {石川達也} and {伊藤竜馬} and {Mostafizar Rahman} and {阪本光星} and {田中篤} and {内海潮音} and {五十部孝典}},
     title = {{SHA Extensionsを用いたAES-basedハッシュ関数の拡張}},
     booktitle = {コンピュータセキュリティシンポジウム 2025 - CSS 2025},
     number = {1G2-2},
     note = {1G2-2},
     year = {2025},
     month = oct,
     url = {https://www.iwsec.org/css/2025/program.html#1G2}
   }

7. ISEC

   SIMONバリアントに対する拡散性能評価の厳密化

   巽浩太 , 渡部颯斗 , 伊藤竜馬 , 大東俊博

   信学技報, 2025年7月

   ISEC2025-56

   Bib

   @article{domestic:ISEC2025-56,
     author = {{巽浩太} and {渡部颯斗} and {伊藤竜馬} and {大東俊博}},
     title = {{SIMONバリアントに対する拡散性能評価の厳密化}},
     journal = {信学技報},
     volume = {125},
     number = {99},
     pages = {258--265},
     note = {ISEC2025-56},
     year = {2025},
     month = jul,
     url = {https://ken.ieice.org/ken/paper/20250709VcLS/}
   }

8. ICSS

   機械学習ベース出力予測攻撃のモデル比較とその解釈可能性

   渡部颯斗 , 伊藤竜馬 , 大東俊博

   信学技報, 2025年3月

   ICSS2024-121

   Bib

   @article{domestic:ICSS2024-121,
     author = {{渡部颯斗} and {伊藤竜馬} and {大東俊博}},
     title = {{機械学習ベース出力予測攻撃のモデル比較とその解釈可能性}},
     journal = {信学技報},
     volume = {124},
     number = {422},
     pages = {407--414},
     note = {ICSS2024-121},
     year = {2025},
     month = mar,
     url = {https://ken.ieice.org/ken/paper/20250307Yc8K/}
   }

9. SCIS

   ロケットチャットのエンドツーエンド暗号化に対する安全性解析

   木村隼人 , 伊藤竜馬 , 峯松一彦 , 五十部孝典

   2025年 暗号と情報セキュリティシンポジウム - SCIS 2025, 2025年1月

   2C2-2

   Award Bib

   SCIS論文賞

   @inproceedings{domestic:SCIS2025:Kimura:2C2-2,
     author = {{木村隼人} and {伊藤竜馬} and {峯松一彦} and {五十部孝典}},
     title = {{ロケットチャットのエンドツーエンド暗号化に対する安全性解析}},
     booktitle = {2025年 暗号と情報セキュリティシンポジウム - SCIS 2025},
     number = {2C2-2},
     note = {2C2-2},
     year = {2025},
     month = jan,
     url = {https://www.iwsec.org/scis/2025/program.html#2C2},
   }

2024

1. CSS

   Link Previewを介した暗号化DMに対する平文回復攻撃

   木村隼人 , 白木章伍 , 伊藤竜馬 , 峯松一彦 , 五十部孝典

   コンピュータセキュリティシンポジウム 2024 - CSS 2024, 2024年10月

   1H6-1

   Award Bib

   優秀論文賞 / エシカルプラクティス賞

   @inproceedings{domestic:CSS2024:Kimura:1H6-1,
     author = {{木村隼人} and {白木章伍} and {伊藤竜馬} and {峯松一彦} and {五十部孝典}},
     title = {{Link Previewを介した暗号化DMに対する平文回復攻撃}},
     booktitle = {コンピュータセキュリティシンポジウム 2024 - CSS 2024},
     number = {1H6-1},
     note = {1H6-1},
     year = {2024},
     month = oct,
     url = {https://www.iwsec.org/css/2024/program.html#1H6},
   }

2. ISEC

   AESのDavies-Meyerモードに対する衝突攻撃

   泰山幸大 , 阪本光星 , 伊藤竜馬 , 髙和真 , 五十部孝典

   信学技報, 2024年7月

   ISEC2024-19

   Award Bib

   情報セキュリティ研究賞

   @article{domestic:ISEC2024-19,
     author = {{泰山幸大} and {阪本光星} and {伊藤竜馬} and {髙和真} and {五十部孝典}},
     title = {{AESのDavies-Meyerモードに対する衝突攻撃}},
     journal = {信学技報},
     volume = {124},
     number = {120},
     pages = {73--80},
     note = {ISEC2024-19},
     year = {2024},
     month = jul,
     url = {https://ken.ieice.org/ken/paper/20240722sc3Q/},
   }

3. CSEC

   DNNによるRTT予測誤差に基づく乱数生成法の提案と評価

   日吉敬祐 , 渡部颯斗 , 伊藤竜馬 , 大東俊博

   研究報告コンピュータセキュリティ, 2024年7月

   Bib

   @article{domestic:2024-CSEC-106,
     author = {{日吉敬祐} and {渡部颯斗} and {伊藤竜馬} and {大東俊博}},
     title = {{DNNによるRTT予測誤差に基づく乱数生成法の提案と評価}},
     journal = {研究報告コンピュータセキュリティ},
     volume = {2024-CSEC-106},
     pages = {413--419},
     year = {2024},
     month = jul,
     url = {https://ipsj.ixsq.nii.ac.jp/ej/?action=pages_view_main&active_action=repository_view_main_item_detail&item_id=237226&item_no=1&page_id=13&block_id=8}
   }

4. ICSS

   SIMONバリアントの脆弱な構造の特定

   渡部颯斗 , 伊藤竜馬 , 大東俊博

   信学技報, 2024年3月

   ICSS2023-92

   Bib

   @article{domestic:ICSS2023-92,
     author = {{渡部颯斗} and {伊藤竜馬} and {大東俊博}},
     title = {{SIMONバリアントの脆弱な構造の特定}},
     journal = {信学技報},
     volume = {123},
     number = {448},
     pages = {166--173},
     note = {ICSS2023-92},
     year = {2024},
     month = mar,
     url = {https://ken.ieice.org/ken/paper/202403220c1T/}
   }

5. ICSS

   分散型SNSプロトコルNostrに対する改ざん攻撃の網羅的調査

   木村隼人 , 伊藤竜馬 , 峯松一彦 , 五十部孝典

   信学技報, 2024年3月

   ICSS2023-69

   Bib

   @article{domestic:ICSS2023-69,
     author = {{木村隼人} and {伊藤竜馬} and {峯松一彦} and {五十部孝典}},
     title = {{分散型SNSプロトコルNostrに対する改ざん攻撃の網羅的調査}},
     journal = {信学技報},
     volume = {123},
     number = {448},
     pages = {1--8},
     note = {ICSS2023-69},
     year = {2024},
     month = mar,
     url = {https://ken.ieice.org/ken/paper/20240321qcCq/}
   }

6. SCIS

   分割統治法SATを用いたAESとCamelliaの最大差分/線形特性確率の導出

   髙和真 , 阪本光星 , 伊藤竜馬 , 芝廉太朗 , 内海潮音 , 五十部孝典

   2024年 暗号と情報セキュリティシンポジウム - SCIS 2024, 2024年1月

   3C4-3

   Award Bib

   イノベーション論文賞

   @inproceedings{domestic:SCIS2024:Taka:3C4-3,
     author = {{髙和真} and {阪本光星} and {伊藤竜馬} and {芝廉太朗} and {内海潮音} and {五十部孝典}},
     title = {{分割統治法SATを用いたAESとCamelliaの最大差分/線形特性確率の導出}},
     booktitle = {2024年 暗号と情報セキュリティシンポジウム - SCIS 2024},
     number = {3C4-3},
     note = {3C4-3},
     year = {2024},
     month = jan,
     url = {https://www.iwsec.org/scis/2024/program.html#3C4},
   }

7. SCIS

   深層学習ベースの出力予測攻撃が共通鍵暗号設計に及ぼす影響

   渡部颯斗 , 伊藤竜馬 , 大東俊博

   2024年 暗号と情報セキュリティシンポジウム - SCIS 2024, 2024年1月

   1C2-2

   Bib

   @inproceedings{domestic:SCIS2024:Watanabe:1C2-2,
     author = {{渡部颯斗} and {伊藤竜馬} and {大東俊博}},
     title = {{深層学習ベースの出力予測攻撃が共通鍵暗号設計に及ぼす影響}},
     booktitle = {2024年 暗号と情報セキュリティシンポジウム - SCIS 2024},
     number = {1C2-2},
     note = {1C2-2},
     year = {2024},
     month = jan,
     url = {https://www.iwsec.org/scis/2024/program.html#1C2}
   }

2023

1. CSS

   分散型SNSプロトコルNostrに対する改ざん攻撃

   木村隼人 , 伊藤竜馬 , 峯松一彦 , 五十部孝典

   コンピュータセキュリティシンポジウム 2023 - CSS 2023, 2023年11月

   2E4-3

   Award Bib

   学生論文賞

   @inproceedings{domestic:CSS2023:Kimura:2E4-3,
     author = {{木村隼人} and {伊藤竜馬} and {峯松一彦} and {五十部孝典}},
     title = {{分散型SNSプロトコルNostrに対する改ざん攻撃}},
     booktitle = {コンピュータセキュリティシンポジウム 2023 - CSS 2023},
     number = {2E4-3},
     note = {2E4-3},
     year = {2023},
     month = nov,
     url = {https://www.iwsec.org/css/2023/program.html},
   }

2022

1. ISEC

   AES instructionを用いたラージブロック置換の改良とその応用

   中橋元輝 , 芝廉太郎 , 阪本光星 , Fukang Liu , 伊藤竜馬 , 峯松一彦 , 五十部孝典

   信学技報, 2022年3月

   ISEC2022-80

   Bib

   @article{domestic:ISEC2022-80,
     author = {{中橋元輝} and {芝廉太郎} and {阪本光星} and {Fukang Liu} and {伊藤竜馬} and {峯松一彦} and {五十部孝典}},
     title = {{AES instructionを用いたラージブロック置換の改良とその応用}},
     journal = {信学技報},
     volume = {121},
     number = {429},
     pages = {188--195},
     note = {ISEC2022-80},
     year = {2022},
     month = mar,
     url = {https://www.ieice.org/ken/paper/20220311cCiY/}
   }

2021

1. CSS

   エンドツーエンド暗号化SFrameに対する安全性評価

   五十部孝典 , 伊藤竜馬 , 峯松一彦

   コンピュータセキュリティシンポジウム 2021 - CSS 2021, 2021年10月

   2E3-3

   Award Bib Slides

   奨励賞 / 山下記念研究賞

   @inproceedings{domestic:CSS2021:Isobe:2E3-3,
     author = {{五十部孝典} and {伊藤竜馬} and {峯松一彦}},
     title = {{エンドツーエンド暗号化SFrameに対する安全性評価}},
     booktitle = {コンピュータセキュリティシンポジウム 2021 - CSS 2021},
     number = {2E3-3},
     note = {2E3-3},
     year = {2021},
     month = oct,
     url = {https://www.iwsec.org/css/2021/program.html#i2E3},
   }

2. IEICE

   PNB解析に基づくストリーム暗号Salsa20への差分攻撃

   宮下翔太郎 , 伊藤竜馬 , 宮地充子

   2021年電子情報通信学会総合大会, 2021年3月

   A-7-4

   Bib

   @inproceedings{domestic:IEICE2021:Miyashita:A-7-4,
     author = {{宮下翔太郎} and {伊藤竜馬} and {宮地充子}},
     title = {{PNB解析に基づくストリーム暗号Salsa20への差分攻撃}},
     booktitle = {2021年電子情報通信学会総合大会},
     number = {A-7-4},
     note = {A-7-4},
     year = {2021},
     month = mar,
     url = {http://www.ieice-taikai.jp/2021general/jpn/program.html}
   }

3. SCIS

   Zoomのエンドツーエンド暗号化に対する安全性評価

   五十部孝典 , 伊藤竜馬

   2021年 暗号と情報セキュリティシンポジウム - SCIS 2021, 2021年1月

   3B3-1

   Award Bib Slides

   イノベーション論文賞

   @inproceedings{domestic:SCIS2021:Isobe:3B3-1,
     author = {{五十部孝典} and {伊藤竜馬}},
     title = {{Zoomのエンドツーエンド暗号化に対する安全性評価}},
     booktitle = {2021年 暗号と情報セキュリティシンポジウム - SCIS 2021},
     number = {3B3-1},
     note = {3B3-1},
     year = {2021},
     month = jan,
     url = {https://www.iwsec.org/scis/2021/program.html#3B3},
   }

4. SCIS

   深層学習を用いたSPNブロック暗号への出力予測攻撃

   木村隼人 , 江村恵太 , 五十部孝典 , 伊藤竜馬 , 小川一人 , 大東俊博

   2021年 暗号と情報セキュリティシンポジウム - SCIS 2021, 2021年1月

   1B1-1

   Bib

   @inproceedings{domestic:SCIS2021:Kimura:1B1-1,
     author = {{木村隼人} and {江村恵太} and {五十部孝典} and {伊藤竜馬} and {小川一人} and {大東俊博}},
     title = {{深層学習を用いたSPNブロック暗号への出力予測攻撃}},
     booktitle = {2021年 暗号と情報セキュリティシンポジウム - SCIS 2021},
     number = {1B1-1},
     note = {1B1-1},
     year = {2021},
     month = jan,
     url = {https://www.iwsec.org/scis/2021/program.html#1B1}
   }

2020

1. CSS

   ストリーム暗号Salsa20におけるProbabilistic Neutral Bitsの解析

   宮下翔太郎 , 伊藤竜馬 , 宮地充子

   コンピュータセキュリティシンポジウム 2020 - CSS 2020, 2020年10月

   2E1-3

   Bib

   @inproceedings{domestic:CSS2020:Miyashita:2E1-3,
     author = {{宮下翔太郎} and {伊藤竜馬} and {宮地充子}},
     title = {{ストリーム暗号Salsa20におけるProbabilistic Neutral Bitsの解析}},
     booktitle = {コンピュータセキュリティシンポジウム 2020 - CSS 2020},
     number = {2E1-3},
     note = {2E1-3},
     year = {2020},
     month = oct,
     url = {https://www.iwsec.org/css/2020/program.html}
   }

2018

1. ISEC

   反復性のある鍵相関を用いた WPA-TKIP に対する平文回復攻撃

   伊藤竜馬 , 宮地充子

   信学技報, 2018年7月

   ISEC2018-48

   Bib Slides

   @article{domestic:ISEC2018-48,
     author = {{伊藤竜馬} and {宮地充子}},
     title = {{反復性のある鍵相関を用いた WPA-TKIP に対する平文回復攻撃}},
     journal = {信学技報},
     volume = {118},
     number = {151},
     pages = {379--386},
     note = {ISEC2018-48},
     year = {2018},
     month = jul,
     url = {https://www.ieice.org/ken/paper/20180726e1Fe/},
   }

2. SCIS

   ストリーム暗号 RC4 における反復性のある新しい鍵相関

   伊藤竜馬 , 宮地充子

   2018年 暗号と情報セキュリティシンポジウム - SCIS 2018, 2018年1月

   2B3-1

   Bib Slides

   @inproceedings{domestic:SCIS2018:Ito:2B3-1,
     author = {{伊藤竜馬} and {宮地充子}},
     title = {{ストリーム暗号 RC4 における反復性のある新しい鍵相関}},
     booktitle = {2018年 暗号と情報セキュリティシンポジウム - SCIS 2018},
     number = {2B3-1},
     note = {2B3-1},
     year = {2018},
     month = jan,
     url = {https://www.iwsec.org/scis/2018/program.html},
   }

2015

1. ICSS

   WPA における RC4 の鍵回復攻撃に向けた新しい線形相関と解析手法

   道廣大喜 , 宮地充子 , 伊藤竜馬

   信学技報, 2015年3月

   ICSS2014-85

   Bib

   @article{domestic:ICSS2014-85,
     author = {{道廣大喜} and {宮地充子} and {伊藤竜馬}},
     title = {{WPA における RC4 の鍵回復攻撃に向けた新しい線形相関と解析手法}},
     journal = {信学技報},
     volume = {114},
     number = {489},
     pages = {133--138},
     note = {ICSS2014-85},
     year = {2015},
     month = mar,
     url = {https://www.ieice.org/ken/paper/20150304rBZE/}
   }

2. SCIS

   WPA における RC4 の内部状態に関する新しい線形相関

   伊藤竜馬 , 宮地充子

   2015年 暗号と情報セキュリティシンポジウム - SCIS 2015, 2015年1月

   2E2-3

   Award Bib Slides

   SCIS論文賞

   @inproceedings{domestic:SCIS2015:Ito:2E2-3,
     author = {{伊藤竜馬} and {宮地充子}},
     title = {{WPA における RC4 の内部状態に関する新しい線形相関}},
     booktitle = {2015年 暗号と情報セキュリティシンポジウム - SCIS 2015},
     number = {2E2-3},
     note = {2E2-3},
     year = {2015},
     month = jan,
     url = {https://www.iwsec.org/scis/2015/program.html#S2E2},
   }

2014

1. ISEC

   RC4 の Long-term Glimpse における新しい Negative Biases

   伊藤竜馬 , 宮地充子

   信学技報, 2014年5月

   ISEC2014-3

   Bib Slides

   @article{domestic:ISEC2014-3,
     author = {{伊藤竜馬} and {宮地充子}},
     title = {{RC4 の Long-term Glimpse における新しい Negative Biases}},
     journal = {信学技報},
     volume = {114},
     number = {24},
     pages = {13--19},
     note = {ISEC2014-3},
     year = {2014},
     month = may,
     url = {https://www.ieice.org/ken/paper/201405094BNu/},
   }

2013

1. CSEC

   非線形変換を含む単純化ストリーム暗号 KCipher-2 への GD 攻撃

   伊藤竜馬 , 岩切宗利

   研究報告コンピュータセキュリティ, 2013年3月

   Bib

   @article{domestic:2013-CSEC-7,
     author = {{伊藤竜馬} and {岩切宗利}},
     title = {{非線形変換を含む単純化ストリーム暗号 KCipher-2 への GD 攻撃}},
     journal = {研究報告コンピュータセキュリティ},
     volume = {2013-CSEC-7},
     pages = {1--7},
     year = {2013},
     month = mar,
     url = {https://ipsj.ixsq.nii.ac.jp/ej/?action=pages_view_main&active_action=repository_view_main_item_detail&item_id=91040&item_no=1&page_id=13&block_id=8}
   }

2. CSEC

   単純化ストリーム暗号 K2 のクロック制御を無効化した GD 攻撃

   伊藤竜馬 , 岩切宗利

   研究報告コンピュータセキュリティ, 2013年3月

   Bib

   @article{domestic:2013-CSEC-6,
     author = {{伊藤竜馬} and {岩切宗利}},
     title = {{単純化ストリーム暗号 K2 のクロック制御を無効化した GD 攻撃}},
     journal = {研究報告コンピュータセキュリティ},
     volume = {2013-CSEC-6},
     pages = {1--6},
     year = {2013},
     month = mar,
     url = {https://ipsj.ixsq.nii.ac.jp/ej/index.php?active_action=repository_view_main_item_detail&page_id=13&block_id=8&item_id=91039&item_no=1}
   }

2026

1. ePrint

   Dialga: A Family of Low-Latency Tweakable Block Ciphers using Multiple Linear Layers (Full Version)

   Subhadeep Banik , Tatsuya Ishikawa , Takanori Isobe , Ryoma Ito , Kazuhiko Minematsu , Kazuma Nakata , Mostafizar Rahman , and Kosei Sakamoto

   IACR Cryptol. ePrint Arch., 2026

   Bib

   @article{DBLP:journals/iacr/BanikIIIMNRS26,
     author = {Banik, Subhadeep and Ishikawa, Tatsuya and Isobe, Takanori and Ito, Ryoma and Minematsu, Kazuhiko and Nakata, Kazuma and Rahman, Mostafizar and Sakamoto, Kosei},
     title = {Dialga: {A} Family of Low-Latency Tweakable Block Ciphers using Multiple
                       Linear Layers (Full Version)},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2026},
     pages = {547},
     year = {2026},
     url = {https://eprint.iacr.org/2026/547},
     timestamp = {Wed, 12 Aug 2026 11:49:08 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/BanikIIIMNRS26.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2025

1. ePrint

   Not in The Prophecies: Practical Attacks on Nostr

   Hayato Kimura , Ryoma Ito , Kazuhiko Minematsu , Shogo Shiraki , and Takanori Isobe

   IACR Cryptol. ePrint Arch., 2025

   Bib Code Website

   @article{DBLP:journals/iacr/KimuraIMSI25,
     author = {Kimura, Hayato and Ito, Ryoma and Minematsu, Kazuhiko and Shiraki, Shogo and Isobe, Takanori},
     title = {Not in The Prophecies: Practical Attacks on Nostr},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2025},
     pages = {1459},
     year = {2025},
     url = {https://eprint.iacr.org/2025/1459},
     timestamp = {Thu, 28 Aug 2025 17:00:42 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/KimuraIMSI25.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. ePrint

   Gravity of the Situation:Security Analysis on Rocket.Chat E2EE

   Hayato Kimura , Ryoma Ito , Kazuhiko Minematsu , and Takanori Isobe

   IACR Cryptol. ePrint Arch., 2025

   Bib Code Website

   @article{DBLP:journals/iacr/KimuraIMI25,
     author = {Kimura, Hayato and Ito, Ryoma and Minematsu, Kazuhiko and Isobe, Takanori},
     title = {Gravity of the Situation:Security Analysis on Rocket.Chat {E2EE}},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2025},
     pages = {2300},
     year = {2025},
     url = {https://eprint.iacr.org/2025/2300},
     timestamp = {Tue, 13 Jan 2026 11:09:23 +0100},
     biburl = {https://dblp.org/rec/journals/iacr/KimuraIMI25.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2024

1. ePrint

   On the Effects of Neural Network-based Output Prediction Attacks on the Design of Symmetric-key Ciphers

   Hayato Watanabe , Ryoma Ito , and Toshihiro Ohigashi

   IACR Cryptol. ePrint Arch., 2024

   Bib

   @article{DBLP:journals/iacr/WatanabeIO24,
     author = {Watanabe, Hayato and Ito, Ryoma and Ohigashi, Toshihiro},
     title = {On the Effects of Neural Network-based Output Prediction Attacks on
                       the Design of Symmetric-key Ciphers},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2024},
     pages = {1310},
     year = {2024},
     url = {https://eprint.iacr.org/2024/1310},
     timestamp = {Sun, 01 Sep 2024 21:15:38 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/WatanabeIO24.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. ePrint

   Key Collisions on AES and Its Applications

   Kodai Taiyama , Kosei Sakamoto , Ryoma Ito , Kazuma Taka , and Takanori Isobe

   IACR Cryptol. ePrint Arch., 2024

   Bib

   @article{DBLP:journals/iacr/TaiyamaSITI24,
     author = {Taiyama, Kodai and Sakamoto, Kosei and Ito, Ryoma and Taka, Kazuma and Isobe, Takanori},
     title = {Key Collisions on {AES} and Its Applications},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2024},
     pages = {1508},
     year = {2024},
     url = {https://eprint.iacr.org/2024/1508},
     timestamp = {Sat, 05 Oct 2024 20:55:34 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/TaiyamaSITI24.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2023

1. ePrint

   Areion: Highly-Efficient Permutations and Its Applications (Extended Version)

   Takanori Isobe , Ryoma Ito , Fukang Liu , Kazuhiko Minematsu , Motoki Nakahashi , Kosei Sakamoto , and Rentaro Shiba

   IACR Cryptol. ePrint Arch., 2023

   Bib Code

   @article{DBLP:journals/iacr/IsobeILMNSS23,
     author = {Isobe, Takanori and Ito, Ryoma and Liu, Fukang and Minematsu, Kazuhiko and Nakahashi, Motoki and Sakamoto, Kosei and Shiba, Rentaro},
     title = {Areion: Highly-Efficient Permutations and Its Applications (Extended
                       Version)},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2023},
     pages = {794},
     year = {2023},
     url = {https://eprint.iacr.org/2023/794},
     timestamp = {Mon, 03 Jul 2023 20:30:02 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/IsobeILMNSS23.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. ePrint

   Parallel SAT Framework to Find Clustering of Differential Characteristics and Its Applications

   Kosei Sakamoto , Ryoma Ito , and Takanori Isobe

   IACR Cryptol. ePrint Arch., 2023

   Bib

   @article{DBLP:journals/iacr/SakamotoII23,
     author = {Sakamoto, Kosei and Ito, Ryoma and Isobe, Takanori},
     title = {Parallel {SAT} Framework to Find Clustering of Differential Characteristics
                       and Its Applications},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2023},
     pages = {1227},
     year = {2023},
     url = {https://eprint.iacr.org/2023/1227},
     timestamp = {Fri, 08 Sep 2023 15:28:09 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/SakamotoII23.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2021

1. ePrint

   Bit-wise Cryptanalysis on AND-RX Permutation Friet-PC

   Ryoma Ito , Rentaro Shiba , Kosei Sakamoto , Fukang Liu , and Takanori Isobe

   IACR Cryptol. ePrint Arch., 2021

   Bib

   @article{DBLP:journals/iacr/ItoSSL021,
     author = {Ito, Ryoma and Shiba, Rentaro and Sakamoto, Kosei and Liu, Fukang and Isobe, Takanori},
     title = {Bit-wise Cryptanalysis on {AND-RX} Permutation Friet-PC},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2021},
     pages = {212},
     year = {2021},
     url = {https://eprint.iacr.org/2021/212},
     timestamp = {Mon, 26 Jul 2021 08:20:04 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/ItoSSL021.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2. ePrint

   Output Prediction Attacks on SPN Block Ciphers using Deep Learning

   Hayato Kimura , Keita Emura , Takanori Isobe , Ryoma Ito , Kazuto Ogawa , and Toshihiro Ohigashi

   IACR Cryptol. ePrint Arch., 2021

   Bib

   @article{DBLP:journals/iacr/0002E0IOO21,
     author = {Kimura, Hayato and Emura, Keita and Isobe, Takanori and Ito, Ryoma and Ogawa, Kazuto and Ohigashi, Toshihiro},
     title = {Output Prediction Attacks on {SPN} Block Ciphers using Deep Learning},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2021},
     pages = {401},
     year = {2021},
     url = {https://eprint.iacr.org/2021/401},
     timestamp = {Mon, 26 Jul 2021 08:20:06 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/0002E0IOO21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

3. ePrint

   Security Analysis of SFrame

   Takanori Isobe , Ryoma Ito , and Kazuhiko Minematsu

   IACR Cryptol. ePrint Arch., 2021

   Bib

   @article{DBLP:journals/iacr/IsobeIM21,
     author = {Isobe, Takanori and Ito, Ryoma and Minematsu, Kazuhiko},
     title = {Security Analysis of SFrame},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2021},
     pages = {424},
     year = {2021},
     url = {https://eprint.iacr.org/2021/424},
     timestamp = {Mon, 26 Jul 2021 08:20:08 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/IsobeIM21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

4. ePrint

   Security Analysis of End-to-End Encryption for Zoom Meetings

   Takanori Isobe and Ryoma Ito

   IACR Cryptol. ePrint Arch., 2021

   Bib

   @article{DBLP:journals/iacr/IsobeI21,
     author = {Isobe, Takanori and Ito, Ryoma},
     title = {Security Analysis of End-to-End Encryption for Zoom Meetings},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2021},
     pages = {486},
     year = {2021},
     url = {https://eprint.iacr.org/2021/486},
     timestamp = {Mon, 26 Jul 2021 08:20:10 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/IsobeI21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

5. ePrint

   Distinguishing and Key Recovery Attacks on the Reduced-Round SNOW-V

   Jin Hoki , Takanori Isobe , Ryoma Ito , Fukang Liu , and Kosei Sakamoto

   IACR Cryptol. ePrint Arch., 2021

   Bib

   @article{DBLP:journals/iacr/HokiIILS21,
     author = {Hoki, Jin and Isobe, Takanori and Ito, Ryoma and Liu, Fukang and Sakamoto, Kosei},
     title = {Distinguishing and Key Recovery Attacks on the Reduced-Round {SNOW-V}},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2021},
     pages = {546},
     year = {2021},
     url = {https://eprint.iacr.org/2021/546},
     timestamp = {Mon, 26 Jul 2021 08:20:12 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/HokiIILS21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

6. ePrint

   State-free End-to-End Encrypted Storage and Chat Systems based on Searchable Encryption

   Keita Emura , Ryoma Ito , Sachiko Kanamori , Ryo Nojima , and Yohei Watanabe

   IACR Cryptol. ePrint Arch., 2021

   Bib

   @article{DBLP:journals/iacr/EmuraIKNW21,
     author = {Emura, Keita and Ito, Ryoma and Kanamori, Sachiko and Nojima, Ryo and Watanabe, Yohei},
     title = {State-free End-to-End Encrypted Storage and Chat Systems based on
                       Searchable Encryption},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2021},
     pages = {953},
     year = {2021},
     url = {https://eprint.iacr.org/2021/953},
     timestamp = {Mon, 09 Aug 2021 16:25:39 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/EmuraIKNW21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

7. ePrint

   Finding Practical Distinguishers for ZUC-256 Using Modular Differences

   Fukang Liu , Willi Meier , Santanu Sarkar , Gaoli Wang , Ryoma Ito , and Takanori Isobe

   IACR Cryptol. ePrint Arch., 2021

   Bib

   @article{DBLP:journals/iacr/LiuM0W0021,
     author = {Liu, Fukang and Meier, Willi and Sarkar, Santanu and Wang, Gaoli and Ito, Ryoma and Isobe, Takanori},
     title = {Finding Practical Distinguishers for {ZUC-256} Using Modular Differences},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2021},
     pages = {1104},
     year = {2021},
     url = {https://eprint.iacr.org/2021/1104},
     timestamp = {Mon, 06 Sep 2021 18:25:17 +0200},
     biburl = {https://dblp.org/rec/journals/iacr/LiuM0W0021.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

8. ePrint

   PNB-based Differential Cryptanalysis of ChaCha Stream Cipher

   Shotaro Miyashita , Ryoma Ito , and Atsuko Miyaji

   IACR Cryptol. ePrint Arch., 2021

   Bib

   @article{DBLP:journals/iacr/MiyashitaIM21,
     author = {Miyashita, Shotaro and Ito, Ryoma and Miyaji, Atsuko},
     title = {PNB-based Differential Cryptanalysis of ChaCha Stream Cipher},
     journal = {{IACR} Cryptol. ePrint Arch.},
     volume = {2021},
     pages = {1537},
     year = {2021},
     url = {https://eprint.iacr.org/2021/1537},
     timestamp = {Fri, 10 Dec 2021 18:59:30 +0100},
     biburl = {https://dblp.org/rec/journals/iacr/MiyashitaIM21.bib},
     bibsource = {dblp computer science bibliography, https://dblp.org}
   }

2024

1. CRYPTREC

   CRYPTREC 暗号技術ガイドライン（軽量暗号）2023年度版

   CRYPTREC暗号技術評価委員会

   2024年4月

   ※ CRYPTREC事務局の主担当として執筆・編集を担当

   Bib PDF

   @techreport{other:CRYPTREC:LightweightGuidelines2023,
     author = {{CRYPTREC暗号技術評価委員会}},
     title = {{CRYPTREC 暗号技術ガイドライン（軽量暗号）2023年度版}},
     institution = {CRYPTREC},
     number = {CRYPTREC GL-2006-2023},
     year = {2024},
     month = apr,
     note = {CRYPTREC事務局の主担当として執筆・編集を担当},
     url = {https://www.cryptrec.go.jp/report/cryptrec-gl-2006-2023.pdf},
   }

2022

1. CRYPTREC

   「CRYPTREC 暗号技術ガイドライン（軽量暗号）」掲載の暗号方式に関する安全性評価の動向調査

   伊藤竜馬

   2022年4月

   Bib PDF

   @techreport{other:CRYPTREC:Ito2022SecurityTrends,
     author = {{伊藤竜馬}},
     title = {{「CRYPTREC 暗号技術ガイドライン（軽量暗号）」掲載の暗号方式に関する安全性評価の動向調査}},
     institution = {CRYPTREC},
     number = {CRYPTREC EX-3101-2021},
     year = {2022},
     month = apr,
     day = {13},
     date = {2022-04-13},
     url = {https://www.cryptrec.go.jp/exreport/cryptrec-ex-3101-2021.pdf},
   }