日本語
The University of Electro-Communications 
Graduate School of Informatics and Engineering, School of Informatics and Engineering 
"Department of Computer and Network Engineering, Cluster II (Emerging Multi-interdisciplinary Engineering)" 

顔写真 Associate Professor 
BAGUS SANTOSO 

 
Personal website  

Career
University of Electro-Communications  Department of Computer and Network Engineering  Assistant Professor  2015/10/01-2020/09/30 
Agency for Science Technology and Research (A*STAR)  Institute for Infocomm Research  Research Scientist I  2011/10/01-2015/09/29 
National Institute of Advanced Industrial Science and Technology  情報セキュリティ研究センター  特別研究員  2009/04/01-2011/09/29 

Academic background
豊田工業高等専門学校  情報工学科 
電気通信大学  電気通信学部  情報通信工学科  2003/03/31  Graduated 
電気通信大学  電気通信学部  情報通信工学科  Master's program  2005/03/31  Completed 
電気通信大学  電気通信学部  情報通信工学科  Doctoral program  2009/03/31  Completed 
電気通信大学  電気通信学部  情報通信工学科  Doctoral program  2009/03/31  Completed 

Academic degrees
工学博士  電気通信大学  2016/03/21 

Outlines of current research
Next Generation Security
Next Generation Security

Public Key Cryptographic (PKC) schemes are an essential technology to build secure communication in networks. However, it has been proven that quantum computers can break all current standard PKC schemes, and moreover, the research on developing practical quantum computers has been gaining momentum in recent years. As countermeasures against the threat from quantum computers, PKC schemes with claims of security against quantum computers have been proposed. However, many of them have
flaws such as: (1) impractical due to large implementation costs (computational, storage, or bandwidth), and (2) lacking in concrete security proof against quantum computers. The main goal of my research is to develop a new paradigm based on (1) computational problems in the binary field which are hard even for quantum computers, and (2) a new framework for proving security against quantum computers, to overcome those flaws and then use it to construct new PKC schemes which require small costs for implementation and are equipped with concrete security proof against quantum computers. As application target, we expect that the results of this project can be applied to secure communication between lightweight devices against quantum computers in networks comprising a large variety of devices such as the Internet of Things (IoT). 

Current research areas
Theory of informatics 
Information network 
Information security 

Research keywords
Cryptography 
Information Security 
Post-Quantum Cryptography 

Current research subjects
Post Quantum Cryptography  Quantum Adversary, Multivariate Polynomials Problem, Lattice Cryptography, Syndrome Decoding Problem, Quantum Random Oracle  2015/10/01-Present  RSA and ECC are widely-used public key cryptosystems and are based on hard computational problems such as integer factorization problem and discrete logarithm problem, respectively. In 1997, P. Shor showed polynomial-time quantum algorithms to solve these problems using a large scale quantum computer. Therefore, before a large scale quantum computer gets realized, we need to develop cryptosystems having a resistance to quantum computer attacks. The research area to study such cryptosystems is called post quantum cryptography (PQC). Our research aims to build the fundamental theory for constructing schemes with resistance to quantum computer attacks and also to analyze the security of existing post quantum cryptographic schemes against practical attacks. 

Published papers
Paper  Yes  Achieving Pairing-Free Aggregate Signatures using Pre-Communication between Signers  Joint  Kaoru Takemure, Yusuke Sakai, Bagus Santoso, Goichiro Hanaoka, Kazuo Ohta  IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences  E104-A/ 9  2021/09 
Paper  Yes  Security Analysis on an El-Gamal-like Multivariate Encryption Scheme Based on Isomorphism of Polynomials  Joint  Yasuhiko Ikematsu, Shuhei Nakamura, Bagus Santoso, Takanori Yasuda  Information Security and Cryptology, 17th International Conference, Inscrypt 2021  LNCS 13007/ 1  2021/08/11  10.1007/978-3-030-88323-2 
Paper  Yes  Strong Converse for Distributed Source Coding with Encryption Using Correlated Keys  Joint  Yasutada Oohama, Bagus Santoso  2021 IEEE Information Theory Workshop (ITW)  ITW/ 2021, 1-6  2021/10/17  10.1109/ITW48936.2021.9611414 
Paper  No  New Post-Quantum Digital Signature Scheme based on MinRank Problem  Bagus Santoso, Yasuhiko Ikematsu, Shuhei Nakamura, Takanori Yasuda  2022 Symposium on Cryptography and Information Security (SCIS 2022)  2022/ 2A5-1, 1-8  2022/01/18 
Paper  No  MinRank Based Three-Pass Identification Scheme with Half Cheating Probability  Joint  Bagus Santoso, Yasuhiko Ikematsu, Shuhei Nakamura, Takanori Yasuda  Computer Security Symposium 2021 (CSS 2021)  2021/ 3E2-3, 1-8  2021/10/26 
View details...

Research presentations
Oral presentation for an academic conference  Shannonワンタイムパッド暗号に置ける秘匿性の必要十分条件の再考察  2020 暗号と情報セキュリティシンポジウム  SCIS/ 2020  No  和田一生、バグス サントソ  2020/01/31 
Oral presentation for an academic conference  事前通信モデルにおけるペアリングを用いない集約署名  2020 Symposium on Cryptography and Information Security  SCIS/ 2020  No  竹牟禮 薫、坂井 祐介、Bagus Santoso、花岡 悟一郎、太田 和夫  2020/01/29 
Oral presentation for an academic conference  単純な構造をもった公開鍵暗号方式の単純化  2020 暗号と情報セキュリティシンポジウム  SCIS/ 2020  No  上田 大輔、バグス サントソ  2020/01/28 
Oral presentation for an academic conference  Concurrently Secure Identification Schemes Based on the Hardness of Ideal Lattice Problems in all Rings and a General Simulatable Sampling  SYMPOSIUM ON INFORMATION THEORY AND ITS APPLICATIONS (SITA) 2019  SITA/ 2019  No  Kaoru Takemure, Bagus Santoso  2019/12/26 
Oral presentation for an academic conference  LWE暗号の計算機における安全性評価  SYMPOSIUM ON INFORMATION THEORY AND ITS APPLICATIONS (SITA) 2019  SITA/ 2019  No  荒井嵩博、バグス サントソ  2019/01/24 
View details...

Awards
情報理論とその応用サブソサイエティ学生優秀発表賞  LWE暗号におけるIND-CPA安全性の再評価  2021/01/22 
View details...

Grants-in-aid for scientific research
New Paradigm to Construct Public Key Cryptographic Schemes for Lightweight Devices with Provable Security against Quantum Attackers  "Scientific research (C), general"  2018/04/01-2022/03/31  Public Key Cryptographic (PKC) schemes are an essential technology to build secure communication in networks. However, it has been proven that quantum computers can break all current standard PKC schemes, and moreover, the research on developing practical quantum computers has been gaining momentum in recent years. The main goal of this proposed research is to develop a new paradigm based on (1) computational problems in the binary field which are hard even for quantum computers, and (2) a new framework for proving security against quantum computers, to overcome those flaws and then use it to construct new PKC schemes which require small costs for implementation and are equipped with concrete security proof against quantum computers. As application target, we expect that the results of this project can be applied to secure communication between lightweight devices against quantum computers in networks comprising a large variety of devices such as the Internet of Things (IoT). 
IoT社会の高度化に必要な多端子情報理論と暗号理論を柱とした安全通信理論の構築  2018/04/01-2023/03/31  IoTの急速な進歩により,悪意を持った第三者(以後敵と記す)のハードウェア攻撃とよばれる暗号系への物理的アクセスが高度化かつ多様化し,秘密情報漏えいの危険性が著しく増大している.本研究は,この問題の根本的解決に挑む.具体的には多端子情報理論と暗号理論を基盤として IoT 環境下での情報漏えいの理論的モデルを構築する.このモデルに基づき,敵から想定される最大級の攻撃を受けた場合も,既存暗号系を変更せずに秘密情報の漏れを防止し,安全通信を維持できるための理論的条件と維持の具体的方法とを与える.理論結果の導出では,研究代表者が開発した独自の手法を更に発展させた手法を用いる.また,理論の検証と実用化への見通しを目的として,IoT 環境下における暗号通信系を実システムあるいは計算機上の仮想システムとして実現して通信実験を行う. 
View details...

Memberships of academic societies
The Institute of Electrical and Electronics Engineers, Inc. (IEEE)  2016/04/01-Present 
Association of Computing Machinery (ACM)  2016/04/01-Present 
International Association for Cryptologic Research (IACR)  2006/02/16-Present 
Institute of Electronics, Information and Communication Engineers (IEICE)  2005/04/01-Present 
View details...

Involvement in conference and research meetings
IEICE Transactions (Japanese Edition)  Chief Secretary  2020/06/01 
第41回情報理論とその応用シンポジウム(SITA2018)  プログラム委員  2018/12/18 
View details...