Associate Professor · Graduate School of Informatics, Nagoya University
Research project
We combine Internet of Things (IoT) devices with blockchain and smart contracts so that device permissions, data sharing, and lifecycle management can be handled in a transparent way.
Detail
Network-connected devices are now used in many places, from homes to factories and vehicles. Some of these devices are managed by trained professionals, while others are operated by ordinary users.
For professional systems, maintenance and lifecycle management are often organized as part of a business process. For consumer Internet of Things (IoT) devices, however, users are usually expected to rely on manuals and software updates to keep devices secure.
Detail
Device logs, sensor readings, and operational data are often collected and reused without the owner clearly seeing how. Manufacturers may put such data to use for monitoring or AI training, while the users themselves have little control or access.
Even when owners do want to share or reuse data from their own devices, the interfaces and permissions needed to do so are frequently unclear or simply not available.
Detail
We are developing a software framework that combines Internet of Things (IoT) devices with Web3 technologies such as blockchain and smart contracts. The goal is to automate device lifecycle management and data sharing in a verifiable way.
Users can grant permissions to manufacturers or third parties, and those permissions are recorded and enforced through smart contracts. By leaving a trace of agreements on the blockchain, the framework improves transparency and accountability.
Detail
The starting point was a blockchain-based secure software update framework for IoT devices (2018); its extended version received an excellent paper award at DICOMO 2022. Managing a device's whole life on a distributed ledger became the prototype for this theme.
The scope has since widened to data sharing. Recent results include access control that anonymizes account information with zero-knowledge proofs (Electronics, 2025), authentication and metadata search based on self-sovereign identity (BCCA 2025), PPDS, a privacy-preserving data sharing model for e-health (BCCA 2025), and flexible edge processing in a blockchain-based IoT data distribution framework (PerCom workshop, 2025) — the building blocks of the IoTxWeb3 framework.
Detail
As this framework spreads, device owners can see for themselves who uses their data and decide how far to allow it, rather than leaving everything to manufacturers.
Manufacturers benefit too: with permissions recorded in a verifiable form, they can build data-driven services while keeping users' trust. The goal is an IoT where devices keep creating value throughout their lives, not only at the point of sale.
Detail
We aim at a decentralized data-sharing infrastructure in which the rights over devices, data, and services are managed automatically by smart contracts, so that individuals and companies can bring their data together with confidence.
The long-term goal is to extend this self-sovereign approach, which does not depend on any single operator, from home IoT to data sharing in industry and mobility.
Detail
The next step is to bring the IoTxWeb3 framework closer to real services. Students' thesis topics are usually chosen from within these directions, through discussion.
Getting started
These overview articles, written in Japanese, are an easier entry point than the research papers below.
Harumi Watanabe, Makoto Imamura, Kenji Hisazumi (eds.), Corona Publishing, 2020. Chapter 2 authored by Yutaka Matsubara.
Yutaka Matsubara, Kinou Zairyo, 2017.
Related links
Open-source software and tools
Projects and related sites
Related publications
2025
Enhancing Account Information Anonymity in Blockchain-Based IoT Access Control Using Zero-Knowledge ProofsYuxiao Wu, Yutaka Matsubara, Shoji Kasahara
Electronics, Vol.14, Issue 14
This paper uses zero-knowledge proofs to hide account information in blockchain-based access control for IoT devices, improving user privacy. Users can prove they have the right to access a device without revealing which account they are, so records on the public blockchain leak less personal information. This addresses the tension between blockchain transparency and privacy.
2025
SSI-Enabled Authentication and Enhanced Metadata Search in Blockchain-based Decentralized IoT Data PlatformsLuyonghe Li, Yuichiro Yasue, Yutaka Matsubara
IEEE 1st International Workshop on Blockchain for Decentralized Trust and Digital Identity (B4TI) at BCCA 2025, Croatia, Oct 2025
This paper adds self-sovereign identity (SSI) based authentication and better metadata search to blockchain-based decentralized IoT data platforms. With SSI, users control their own identity credentials instead of depending on a central provider, which matches the decentralized nature of the platform. Improved metadata search also makes shared IoT data easier to find and use.
2025
PPDS: A Practical and Privacy-Preserving Data Sharing Model for Blockchain-Based IoT e-Health Systems Using ECC, Zero-Knowledge Proof, and Access ControlYuxiao Wu, Kenta Kawai, Yutaka Matsubara
IEEE International Conference on Blockchain Computing and Applications (BCCA 2025), Croatia, Oct 2025
This paper proposes PPDS, a data sharing model for blockchain-based IoT healthcare systems that protects privacy using elliptic curve cryptography, zero-knowledge proofs, and access control. Health data is sensitive, so the model lets patients share records with the right parties while keeping identities and contents protected. The cryptographic building blocks are combined with practicality on IoT devices in mind.
2025
Flexible Edge Processing in Blockchain-based Secure IoT Data Distribution FrameworkKenta Kawai, Yuxiao Wu, Yutaka Matsubara, Hiroaki Takada
BRAIN 2025 at PerCom 2025, Washington D.C., Mar 2025
This paper adds flexible edge processing to a blockchain-based framework for secure IoT data distribution, so data can be processed near its source. Processing data near where it is generated reduces network traffic and avoids sending raw personal data to distant servers. The blockchain still guarantees trust in the exchanged results.
2023
Supply-Demand Matching System for Circulating IoT Device InformationKenta Kawai, Yutaka Matsubara, Hiroaki Takada
DICOMO 2023, pp.45-56
2022
Software Update Framework for IoT Devices Using BlockchainRyota Nakanishi, Yutaka Matsubara, Hiroaki Takada
DICOMO 2022
Excellent Paper Award.
2022
Excellent Paper Award for Software Update Framework for IoT Devices Using BlockchainRyota Nakanishi, Yutaka Matsubara, Hiroaki Takada
DICOMO 2022
2020
Tsunagaru! Kiso Gijutsu IoT Nyumon (Chapter 2: Security)Harumi Watanabe, Makoto Imamura, Kenji Hisazumi (eds.)
Corona Publishing
An introductory textbook chapter on security for IoT systems, explaining basic threats and countermeasures for connected devices. It walks through how attackers can reach devices over the network and what basic defenses such as encryption and authentication do. The chapter is written for students taking their first steps into IoT.
Yutaka Matsubara authored Chapter 2.
2020
Secure Remote Software Update for Mindstorms EV3Daichi Ito, Yutaka Matsubara, Hiroaki Takada
19th Complex Systems Micro Symposium, Sapporo
2020
Performance Evaluation of QUIC for Lightweight Secure Communication on IoT DevicesTaiga Komatsu, Yutaka Matsubara, Hiroaki Takada
SCIS 2020, Kochi
2018
Secure Update Framework for IoT Devices Using Blockchain TechnologyKeigo Nagara, Yutaka Matsubara, Hiroaki Takada
ESS 2018 Proceedings, Gero, pp.36-39
2018
Performance Evaluation of TLS 1.3 for IoT DevicesTaiga Komatsu, Yutaka Matsubara, Hiroaki Takada
Computer Security Symposium 2018, Nagano, pp.569-576
2018
Secure Update Framework for IoT Devices Using Blockchain TechnologyKeigo Nagara, Yutaka Matsubara, Hiroaki Takada
SWEST20, Gero
2017
Automotive Security and IoTYutaka Matsubara
Kinou Zairyo, Jun. 2017 serial article
A review article introducing the current state of automotive security in the context of the IoT era. It describes how connecting cars to networks and smartphones creates new attack paths, and outlines the countermeasures the industry is adopting. The article is written to be accessible to readers outside the software field.
2017
Portable DoS Test Tool for Embedded SystemsKeigo Nagara, Katsunori Aoki, Yutaka Matsubara, Hiroaki Takada
ESS 2017 WiP, Gero
2017
Attack Performance Evaluation of Mirai Malware on Embedded SystemsKeigo Nagara, Yutaka Matsubara, Katsunori Aoki, Hiroaki Takada
IPSJ Research Report 2017-EMB-44 No.41, Okinawa, pp.1-6
2017
Open-source Software-based Portable DoS Test Tool for IoT DevicesKeigo Nagara, Katsunori Aoki, Yutaka Matsubara, Hiroaki Takada
Workshop on Internet of Things Security and Privacy with ACM CCS, Dallas
Related themes
Trust in a single computer
We study how to keep mixed-criticality systems fast, predictable, and safe even when many applications share CPUs, memory, storage, and networks.
Trust in systems of systems
We study Systems of Systems (SoS — arrangements in which multiple independent systems cooperate to achieve an emergent purpose) as socio-technical systems in which autonomous actors interact, and we aim to establish engineering methods for designing their overall behavior.
Cross-cutting theme
Across all three pillars, we develop techniques for checking whether a system actually deserves trust and for explaining why — fuzzing for concurrent software, formal verification, security analysis, and assurance cases.