• Annual Conference of KIPS
• /
• 2019.10a
• /
• pp.110-112
• /
• 2019

블록체인은 4차 산업혁명 핵심 키워드 중 하나이다. 하지만 현재 블록체인 기술을 접목시킨 사례는 굉장히 적다. 그것은 블록체인 시스템에서 트랜잭션을 처리하는 속도가 느린 것을 이유로 볼 수 있다. 기존에 빠른 속도로 많은 트랜잭션을 처리하던 시스템에 비해 느린 블록체인 기술을 접목시키는 것은 어려움이 있다. 때문에 블록체인 연구는 합의 알고리즘, 다양한 네트워크 구성 등을 이용하여 트랜잭션 처리 속도를 늘리는 연구들이 진행 중이다. 본 논문에서는 오픈소스 프로젝트인 하이퍼레저 패브릭의 트랜잭션 처리 속도를 향상시키기 위한 방법을 제안한다. 패브릭은 블록에 트랜잭션을 추가하기 위해 독립적으로 수행되는 3단계를 거쳐 수행된다. 그 중 1번째 단계인 보증 단계의 최적화를 진행한다. 패브릭에서 클라이언트로부터 피어가 반복적인 요청을 받을 때 매번 같은 네트워크에 속해 있는 노드인지 확인을 하게 되는데, 한번 보증을 완료한 노드는 일정 기간 동안 노드 확인을 거치지 않고 체인 코드를 수행하여 트랜잭션을 처리하도록 하는 방법을 제안한다.

• Journal of Information Processing Systems
• /
• v.16 no.4
• /
• pp.743-749
• /
• 2020

Internet of Things (IoT) is a growing technology along with artificial intelligence (AI) technology. Recently, increasing cases of developing knowledge services using information collected from sensor data have been reported. Communication is required to connect the IoT and AI, and 5G mobile networks have been widely spread recently. IoT, AI services, and 5G mobile networks can be configured and used as sensor-mobile edge-server. The sensor does not send data directly to the server. Instead, the sensor sends data to the mobile edge for quick processing. Subsequently, mobile edge enables the immediate processing of data based on AI technology or by sending data to the server for processing. 5G mobile network technology is used for this data transmission. Therefore, this study examines the challenges, opportunities, and solutions used in each type of technology. To this end, this study addresses clustering, Hyperledger Fabric, data, security, machine vision, convolutional neural network, IoT technology, and resource management of 5G mobile networks.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.31 no.3
• /
• pp.341-351
• /
• 2021

Recently, user-driven privacy control technology, such as distributed ID management, has been gaining attention. However, the existing blockchain-based access control studies have not provided a sufficient level of privacy control method to users. This paper proposes a method that combines permissioned blockchain technology and a recent privacy control standard. To allow users to participate in privacy control, a token-based user access control service that conforms to the UMA2 standard was applied to the blockchain dApp. By combining the blockchain and UMA2, the proposed method provides a user-centered privacy control function that the existing blockchain could not provide. In addition, we solved the problem of privacy, security, and availability of entities, which are the disadvantages of UMA2.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.12
• /
• pp.4400-4419
• /
• 2021

In the 4th Industrial Revolution, the healthcare industry is undergoing a paradigm shift from post-care and management systems based on diagnosis and treatment to disease prevention and management based on personal precision medicine. To optimize medical services for individual patients, an open ecosystem for the healthcare industry that allows the exchange and utilization of personal health records (PHRs) is required. However, under the current system of hospital-centered data management, it is difficult to implement the linking and sharing of PHRs in practice. To address this problem, in this study, we present the design and implementation of a patient-centered PHR platform using blockchain technology. This platform achieved transparency and reliability in information management by eliminating the risk of leakage and tampering/altering personal information, which could occur when using a PHR. In addition, the patient-consent system was applied to a PHR; thus, the patient acted as the user with ownership. The proposed blockchain-based PHR platform enables the integration of personal medical information with scattered distribution across multiple hospitals, and allows patients to freely use their health records in their daily lives and emergencies. The proposed platform is expected to serve as a stepping stone for patient-centered healthcare data management and utilization.

• Journal of Information Processing Systems
• /
• v.19 no.1
• /
• pp.89-97
• /
• 2023

With the growth of Internet-of-Things (IoT) technologies, the number of IoT devices developers need to manage has increased exponentially. Many IoT standards have been proposed to allow those devices to communicate efficiently in day-to-day tasks. However, we lack trusted interworking entities for devices from different standards to collaborate securely. This paper proposes a blockchain platform that bridges multiple heterogeneous IoT platforms to co-exist and interwork. Specifically, we designed an interworking proxy application entity (IPE) implemented as a chaincode in Hyperledger Fabric to collect and process data coming from/to oneM2M and LWM2M architecture. The use of blockchain will guarantee network reliability and data integrity so that cross-standard communications can be audited and processed securely. Based on our evaluation, we show that the interworking between oneM2M and LWM2M through our blockchain platform is feasible. Furthermore, the proposed system can process up to 206 transactions per second with 1,000 running applications, which is about an 87% increase from the previously referenced study.

• International conference on construction engineering and project management
• /
• 2022.06a
• /
• pp.385-392
• /
• 2022

As energy-saving techniques based on human behavior patterns have recently become an issue, the occupant-centered control system is adopted for estimating personal preference of indoor environment and optimizing environmental comfort and energy consumption. Accordingly, IoT devices have been used to collect indoor environmental quality (IEQ) data and personal data. However, the need to safely collect and manage data has been emerged due to cybersecurity issues. Therefore, this paper aims to present a framework that can safely transmit occupant-centered data collected from IoT to a private blockchain server using Hyperledger fabric. In the case study, the minimum value product of the mobile application and smartwatch application was developed to evaluate the usability of the proposed blockchain-based occupant-centered data collection framework. The results showed that the proposed framework could collect data safely and hassle-free in the daily life of occupants. In addition, the performance of the blockchain server was evaluated in terms of latency and throughput when ten people in a single office participated in the proposed data collection framework. Future works will further apply the proposed data collection framework to the building management system to automatically collect occupant data and be used in the HVAC system to reduce building energy consumption without security issues.

• Journal of the Korea Convergence Society
• /
• v.12 no.4
• /
• pp.51-60
• /
• 2021

Recent advances in network and hardware technologies have led to active research and multiple network technologies that fuse blockchain technologies with security. We propose a system model that analyzes technologies using existing blockchain and verifies the integrity of files using private blockchain in a limited environment. The proposed model can be written as a chain code of Hyperleisure Fabric, a private blockchain platform, and verified for integrity of files through Hyperleisure Explorer, a private blockchain integrated management platform. The system performance of the proposed model was analyzed from a developer perspective and from a user perspective. As a result of the analysis, there are compatibility problems according to the version of various modules to run the blockchain platform, and only limited elements such as chain code status and groups can be checked.

• Journal of the Korea Society of Computer and Information
• /
• v.26 no.2
• /
• pp.69-78
• /
• 2021

In this paper, we propose a implementation plan of the human resource pool recruitment system using private (permitted) blockchain. The term Human Resource has become commonly used and has come to recognize human resources as resources. Despite these changes, the use of human resource pools has been sluggish. Once entered, information is often not updated on a regular basis and does not provide sharing, searching, carrier management and anti-counterfeiting. In this research, in order to provide a human resource pool recruitment system that utilizes private (permitted) blockchain, we first used the blockchain network to enable sharing and searching of human resource pools, and to use keywords. Used to get results that meet certain conditions. Second, we added an institutional verification process to ensure the integrity of the input data and prepared preventive measures in the non-technical part by utilizing the structural characteristics of the blockchain to prevent counterfeiting and alteration. Third, we designed and implemented a Dapp (Decentralized application) that includes a Web UI so that each of the three groups can control the blockchain and the predefined processes and business logic.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.32 no.6
• /
• pp.1103-1112
• /
• 2022

Blockchain technology is widespread in everyday life and various industry fields. It guarantees integrity and transparency between blockchain network participants through a distributed ledger. The smart contract is modifying and managing the distributed ledger, which is the most important component of guaranteeing integrity and transparency of blockchain network. Still, smart contracts are also a component of blockchain networks, it is disclosed to network participants transparently. For this reason, the vulnerability of smart contracts could be revealed easily. To mitigate this, various studies are leveraging TEE to guarantee the confidentiality of smart contracts. In existing studies, TEE provides confidentiality of smart contracts but guaranteeing the integrity of smart contracts is out of their scope. In this study, we provide not only the confidentiality of smart contracts but also their integrity, by guaranteeing the CFI of smart contracts within TEE.

• International Journal of Computer Science & Network Security
• /
• v.22 no.12
• /
• pp.37-50
• /
• 2022

Modern supply chains include multiple activities from collecting raw materials to transferring final products. These activities involve many parties who share a huge amount of valuable data, which makes managing supply chain systems a challenging task. Current supply chain management (SCM) systems adopt digital technologies such as the Internet of Things (IoT) and blockchain for optimization purposes. Although these technologies can significantly enhance SCM systems, they have their own limitations that directly affect SCM systems. Security, performance, and scalability are essential components of SCM systems. Yet, confidentiality and scalability are one of blockchain's main limitations. Moreover, IoT devices are lightweight and have limited power and storage. These limitations should be considered when developing blockchain-based IoT-SCM systems. In this paper, the requirements of efficient supply chain systems are analyzed and the role of both IoT and blockchain technologies in providing each requirement are discussed. The limitations of blockchain and the challenges of IoT integration are investigated. The limitations of current literature in the same field are identified, and a secure and scalable blockchain-based IoT-SCM system is proposed. The proposed solution employs a Hyperledger fabric blockchain platform and tackles confidentiality by implementing private data collection to achieve confidentiality without decreasing performance. Moreover, the proposed framework integrates IoT data to stream live data without consuming its limited resources and implements a dualstorge model to support supply chain scalability. The proposed framework is evaluated in terms of security, throughput, and latency. The results demonstrate that the proposed framework maintains confidentiality, integrity, and availability of on-chain and off-chain supply chain data. It achieved better performance through 31.2% and 18% increases in read operation throughput and write operation throughput, respectively. Furthermore, it decreased the write operation latency by 83.3%.