KEIO RESEARCHERS INFORMATION SYSTEM

Papers 【 Display / hide 】

Papers 【 Display / hide 】

• Fabchain: Managing Audit-able 3D Print Job over Blockchain

  Abe R., Suzuki S., Saito K., Tanaka H., Nakamura O., Murai J.

  IEEE International Conference on Blockchain and Cryptocurrency, ICBC 2022 （IEEE International Conference on Blockchain and Cryptocurrency, ICBC 2022)   2022

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  Improvements in fabrication devices such as 3D printers are becoming possible for personal fabrication to freely fabricate any products. To clarify who is liable for the product, the fabricator should keep the fabrication history in an immutable and sustainably accessible manner. In this paper, we propose a new scheme, Fabchain, that can record the fabrication history in such a manner. By utilizing a scheme that employs a blockchain as an auditable communication channel, Fabchain manages print jobs for the fabricator's 3D printer over the blockchain, while maintaining a history of a print job. We implemented Fabchain on Ethereum and evaluated the performance for recording a print job. Our results demonstrate that Fabchain can complete communication of a print job sequence in less than 1 minute on the Ethereum test network. We conclude that Fabchain can manage a print job in a reasonable duration for 3D printing, while satisfying the requirements for immutability and sustainability.

  • Access to Document (DOI)

• Attack incentive and security of exchanging tokens on proof-of-work blockchain

  Abe R., Teramoto K., Nakamura K., Takahashi M.

  Asian Internet Engineering Conference, AINTEC 2018 （Asian Internet Engineering Conference, AINTEC 2018)     32 - 37 2018.11

  ISSN  9781450361316

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  © 2018 Copyright held by the owner/author(s). In a consensus algorithm based on Proof-of-Work, miners are motivated by crypto rewards. Furthermore, security is guaranteed because a cost of a 50% attack chance is higher than the potential rewards. However, because of the sudden price jump of cryptocurrencies and cheap prices of mining machines like ASICs, the cost and profit were on equilibrium for Bitcoin in 2017. In this situation, attackers are motivated by the balance between hash power and profits. In this paper, we describe that there is relevance between mining power on the network and price of tokens that can be taken securely on a blockchain. Users who exchange tokens on the PoW blockchain should monitor mining power and exchange tokens cheaper than the attack cost so that profit and cost of the attacker are not in equilibrium.

  • Access to Document (DOI)

• Mitigating bitcoin node storage size by DHT

  Abe R., Suzuki S., Murai J.

  Asian Internet Engineering Conference, AINTEC 2018 （Asian Internet Engineering Conference, AINTEC 2018)     17 - 23 2018.11

  ISSN  9781450361316

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  © 2018 ACM. A type of Bitcoin node called “Full Node” has to hold the entire of historical transaction data called “Blockchain” to verify that new transactions are correct or not. To operate nodes as Full Nodes, the required storage size will be too large for resource-constrained devices. In this paper, to mitigate storage size, we propose a storage load balancing scheme by distributed storage based on Distributed Hash Table (DHT). By our scheme, nodes in a DHT cluster can behave like Full Nodes without holding the entire of the blockchain.

  • Access to Document (DOI)

• Storage Protocol for Securing Blockchain Transparency

  Abe R., Watanabe H., Ohashi S., Fujimura S., Nakadaira A.

  Proceedings - International Computer Software and Applications Conference （Proceedings - International Computer Software and Applications Conference)  2   577 - 581 2018.06

  ISSN  9781538626665

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  © 2018 IEEE. There are several studies that propose identity management that utilizes blockchain technology. In Ethereum, the main programmable blockchain system, data on a blockchain are saved as encoded binaries for executing automatic verification. To decode a binary, users need to know the application binary interfaces (ABI) that describes the data structure of the registered information. However, the manner by which ABI are shared in the current blockchain protocol is opaque. To resolve this problem, we describe a new protocol for embedding the ABI on a blockchain transaction when a registrant registers information. Our method enables users to read registered data with information on the blockchain alone, and it guarantees transparency without requiring users to trust third parties.

  • Access to Document (DOI)

Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• INTRODUCTION TO TRUSTED INTERNET

  2023

• FUNDAMENTALS OF INFORMATION TECHNOLOGY 2

  2023

• FUNDAMENTALS OF INFORMATION TECHNOLOGY 1

  2023

• FUNDAMENTALS OF INFORMATION TECHNOLOGY 2

  2022

• FUNDAMENTALS OF INFORMATION TECHNOLOGY 1

  2022

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