• 한국가스학회지
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• 제26권3호
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• pp.38-44
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• 2022

전세계적으로 저탄소 친환경에너지로 다변화 정책이 진행되고 있으며, 그 정책 중 하나가 수소경제 활성화이다. 수소경제 활성화 정책으로 수소 공급을 위한 수소충전소의 보급이 가속화됨에 따라 사고발생의 위험도 커지고 있다. 수소의 폭발사고는 대부분 대형사고로 이어지기 때문에 수소에너지를 사용함에 있어 안전성을 확보하는 것은 매우 중요하다. 수소에너지를 활용하기 위해서는 액화수소의 생산, 저장, 운송 등에 사용될 수소저장 용기의 안전성 확보는 반드시 필요하다. 본 논문에서는 수소충전용 압력용기의 구조안전성을 평가하기 위해 가스 압력에 대한 거동특성을 유한요소해석으로 분석하였다. 압력용기의 재료는 SA-372 Grade J / Class 70을 사용하였고, 해석모델은 압력용기가 축대칭 형상이므로 1/4 형상만 고려하여 6면체 메쉬를 적용하였다. 수소가스 압력용기를 사용 최고 압력에서 유한요소해석을 하였으며, 해석 결과인 용기의 von Mises Stress와 변형량, 변형률 에너지 밀도를 관찰하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권11호
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• pp.3182-3203
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• 2023

With the growing adoption of cloud-based technologies, maintaining the privacy and security of cloud data has become a pressing issue. Privacy-preserving encryption schemes are a promising approach for achieving cloud data security, but they require careful design and implementation to be effective. The integrated approach to cloud data security that we suggest in this work uses CogniGate: the orchestrated permissions protocol, index trees, blockchain key management, and unique Opacus encryption. Opacus encryption is a novel homomorphic encryption scheme that enables computation on encrypted data, making it a powerful tool for cloud data security. CogniGate Protocol enables more flexibility and control over access to cloud data by allowing for fine-grained limitations on access depending on user parameters. Index trees provide an efficient data structure for storing and retrieving encrypted data, while blockchain key management ensures the secure and decentralized storage of encryption keys. Performance evaluation focuses on key aspects, including computation cost for the data owner, computation cost for data sharers, the average time cost of index construction, query consumption for data providers, and time cost in key generation. The results highlight that the integrated approach safeguards cloud data while preserving privacy, maintaining usability, and demonstrating high performance. In addition, we explore the role of differential privacy in our integrated approach, showing how it can be used to further enhance privacy protection without compromising performance. We also discuss the key management challenges associated with our approach and propose a novel blockchain-based key management system that leverages smart contracts and consensus mechanisms to ensure the secure and decentralized storage of encryption keys.

• 중소기업융합학회논문지
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• 제6권4호
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• pp.31-36
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• 2016

사용자 인증은 네트워크 보안하는 첫 번째 단계이다. 인증의 유형은 많이 있으며, 하나 이상의 인증 방식은 네트워크 내의 사용자의 인증을 보다 안전하게 한다. 하지만 생체 인증 제외하고, 대부분의 인증 방법은 복사 할 수 있다. 또한 다른 사람이 타인의 인증을 악용 할 수 있다. 따라서, 하나 이상의 인증 방식은 안전한 인증을 위해 사용되어야한다. 보안을 너무 강조하게 되면 비효율적이기 때문에, 효율적이면서 안전한 시스템을 구축하기 위한 연구가 많이 진행되고 있다. 본 논문은 사용자의 행동에 기초하여 인증 방안을 제시한다. 본 논문에서 제시한 방법은 안전하고 효율적인 통신을 제공하여 클라우드 기반의 모든 시스템에서 사용자 인증에 적용될 수 있으며, 빅데이터 분석을 통한 보다 정확한 사용자 인증을 통해 안전한 통신에 기여할 것으로 기대한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권11호
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• pp.2769-2792
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• 2013

In this paper, we propose an authenticated key agreement scheme, TinyIBAK, based on the identity-based cryptography and bilinear paring, for large scale sensor networks. We prove the security of our proposal in the random oracle model. According to the formal security validation using AVISPA, the proposed scheme is strongly secure against the passive and active attacks, such as replay, man-in-the middle and node compromise attacks, etc. We implemented our proposal for TinyOS-2.1, analyzed the memory occupation, and evaluated the time and energy performance on the MICAz motes using the Avrora toolkits. Moreover, we deployed our proposal within the TOSSIM simulation framework, and investigated the effect of node density on the performance of our scheme. Experimental results indicate that our proposal consumes an acceptable amount of resources, and is feasible for infrequent key distribution and rekeying in large scale sensor networks. Compared with other ID-based key agreement approaches, TinyIBAK is much more efficient or comparable in performance but provides rekeying. Compared with the traditional key pre-distribution schemes, TinyIBAK achieves significant improvements in terms of security strength, key connectivity, scalability, communication and storage overhead, and enables efficient secure rekeying.

• 한국멀티미디어학회논문지
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• 제13권1호
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• pp.93-101
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• 2010

USB 메모리는 휴대성과 가격대비 고용량을 제공하는 이동형 저장매체로 많은 사용자를 확보하고 있다. 이러한 USB 메모리의 분실 및 도난을 통하여 개인 정보 유출 사건이 증가함에 따라 보안USB 솔루션이 개발되어 사용자들에게 제공되고 있다. 하지만 보안USB의 사용 불편함과 보안 취약점이 발견되고 있어 더욱 안전하고 사용자 편의를 제공하는 보안 솔루션의 필요성이 대두되고 있다. 본 논문은 기존의 이동형 저장매체를 위한 보안 솔루션을 분석하고 더욱 안전하고 사용자 편의성을 제공하는 보안 솔루션을 제시하고자 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.924-944
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• 2017

Telecare Medical Information System (TMIS) helps the patients to gain the health monitoring information at home and access medical services over the mobile Internet. In 2015, Das et al proposed a secure and robust user AKA scheme for hierarchical multi-medical server environment in TMIS, referred to as DAKA protocol, and claimed that their protocol is against all possible attacks. In this paper, we first analyze and show DAKA protocol is vulnerable to internal attacks, impersonation attacks and stolen smart card attack. Furthermore, DAKA protocol also cannot provide confidentiality. We then propose a lightweight pseudonym AKA protocol for multi-medical server architecture in TMIS (short for PAKA). Our PAKA protocol not only keeps good security features declared by DAKA protocol, but also truly provides patient's anonymity by using pseudonym to protect sensitive information from illegal interception. Besides, our PAKA protocol can realize authentication and key agreement with energy-saving, extremely low computation cost, communication cost and fewer storage resources in smart card, medical servers and physical servers. What's more, the PAKA protocol is proved secure against known possible attacks by using Burrows-Abadi-Needham (BAN) logic. As a result, these features make PAKA protocol is very suitable for computation-limited mobile device.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권8호
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• pp.2042-2060
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• 2013

In wireless sensor networks (WSNs), energy efficiency is one of the most essential design considerations, since sensor nodes are resource constrained. Group communication can reduce WSNs communication overhead by sending a message to multiple nodes in one packet. In this paper, in order to simultaneously resolve the transmission security and scalability in WSNs group communications, we propose a hierarchical cluster-based secure and scalable group key management scheme, called HRKT, based on logic key tree and route key tree structure. The HRKT scheme divides the group key into cluster head key and cluster key. The cluster head generates a route key tree according to the route topology of the cluster. This hierarchical key structure facilitates local secure communications taking advantage of the fact that the nodes at a contiguous place usually communicate with each other more frequently. In HRKT scheme, the key updates are confined in a cluster, so the cost of the key updates is reduced efficiently, especially in the case of massive membership changes. The security analysis shows that the HRKT scheme meets the requirements of group communication. In addition, performance simulation results also demonstrate its efficiency in terms of low storage and flexibility when membership changes massively.

• 대한안전경영과학회지
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• 제19권3호
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• pp.123-128
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• 2017

Logistics companies distinguish between medium-sized business and small business according to the size of enterprises. Of course, conglomerates are called global corporations. In this study, mid-sized companies over a certain size or more and those below are classified and decide the priorities among important factors to secure competitiveness in logistics companies are determined through AHP technique. Mid-sized companies are companies that can provide more than two logistics services. For example, they provide warehousing and transportation services in the same time. small companies are companies that can mostly provide one functional service. Warehousing, transportation, manpower, and information are listed as factors in this study. As a result of the study, medium-sized companies emphasized on the importance of transportation. When it comes to small companies, warehousing was emphasized as an important factor. Due to the simultaneous and contemporary service of warehousing and transportation in small-sized company, the reliable image of the company will be underestimated in case of delays in transportation. Competitiveness will also be weakened. Global corporations or conglomerates will start to consider relocating warehousing areas to others except for the central storage hub. They won't plan to invest directly, either. Therefore, it will be possible to secure competitiveness by providing the function of warehousing and to signed easily partnership.

• 상하수도학회지
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• 제30권5호
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• pp.533-543
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• 2016

Supplying clean and safe water to people is facing both quantitative and qualitative challenges. Due to climate change, access to freshwater becomes increasingly difficult, while pollution from various sources decreases the public trust in water quality. Managed aquifer recharge (MAR) which stores and uses surface water in aquifer is receiving attention as a new technology to secure freshwater. Recently, there is a global expansion in the attempt to combine general purification plants and hazard analysis and critical control point (HACCP) which manages all the process from raw material to consumer for food safety. This research is about an attempt to apply HACCP to the drinking water supply process using MAR to secure both quantity and quality of drinking water. The study site is a MAR plant being constructed in the downstream area of the Nakdong River Basin, South Korea. The incorporation of HACCP with MAR-based water supply system is expected to enhance the safety and reliability of drinking water.

• Journal of Communications and Networks
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• 제15권4호
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• pp.422-429
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• 2013

Advances in wireless sensor network (WSN) technology have enabled small and low-cost sensors with the capability of sensing various types of physical and environmental conditions, data processing, and wireless communication. In the WSN, the sensor nodes have a limited transmission range and their processing and storage capabilities as well as their energy resources are limited. A triple umpiring system has already been proved for its better performance in WSNs. The clustering technique is effective in prolonging the lifetime of the WSN. In this study, we have modified the ad-hoc on demand distance vector routing by incorporating signal-to-noise ratio (SNR) based dynamic clustering. The proposed scheme, which is an efficient and secure routing protocol for wireless sensor networks through SNR-based dynamic clustering (ESRPSDC) mechanisms, can partition the nodes into clusters and select the cluster head (CH) among the nodes based on the energy, and non CH nodes join with a specific CH based on the SNR values. Error recovery has been implemented during the inter-cluster routing in order to avoid end-to-end error recovery. Security has been achieved by isolating the malicious nodes using sink-based routing pattern analysis. Extensive investigation studies using a global mobile simulator have shown that this hybrid ESRP significantly improves the energy efficiency and packet reception rate as compared with the SNR unaware routing algorithms such as the low energy aware adaptive clustering hierarchy and power efficient gathering in sensor information systems.