• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권3호
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• pp.1523-1545
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• 2019

Cloud computing is now a widespread and economical option when data owners need to outsource or share their data. Designing secure and efficient data access control mechanism is one of the most challenging issues in cloud storage service. Anonymous broadcast encryption is a promising solution for its advantages in the respects of computation cost and communication overload. We bring forward an efficient anonymous identity-based broadcast encryption construction combined its application to the data access control mechanism in cloud storage service. The lengths for public parameters, user private key and ciphertext in the proposed scheme are all constant. Compared with the existing schemes, in terms of encrypting and decrypting computation cost, the construction of our scheme is more efficient. Furthermore, the proposed scheme is proved to achieve adaptive security against chosen-ciphertext attack adversaries in the standard model. Therefore, the proposed scheme is feasible for the system of data access control in cloud storage service.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권11호
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• pp.4522-4536
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• 2020

Nowadays, cloud is the fastest emerging technology in the IT industry. We can store and retrieve data from the cloud. The most frequently occurring problems in the cloud are security and privacy preservation of data. For improving its security, secret information must be protected from various illegal accesses. Numerous traditional cryptography algorithms have been used to increase the privacy in preserving cloud data. Still, there are some problems in privacy protection because of its reduced security. Thus, this article proposes an ElGamal Elliptic Curve (EGEC) Homomorphic encryption scheme for safeguarding the confidentiality of data stored in a cloud. The Users who hold a data can encipher the input data using the proposed EGEC encryption scheme. The homomorphic operations are computed on encrypted data. Whenever user sends data access permission requests to the cloud data storage. The Cloud Service Provider (CSP) validates the user access policy and provides the encrypted data to the user. ElGamal Elliptic Curve (EGEC) decryption was used to generate an original input data. The proposed EGEC homomorphic encryption scheme can be tested using different performance metrics such as execution time, encryption time, decryption time, memory usage, encryption throughput, and decryption throughput. However, efficacy of the ElGamal Elliptic Curve (EGEC) Homomorphic Encryption approach is explained by the comparison study of conventional approaches.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2011년도 춘계학술발표대회
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• pp.871-874
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• 2011

The fast emerging of network technology and the high demand of computing resources have prompted many organizations to outsource their storage and computing needs. Cloud based storage services such as Microsoft's Azure and Amazon's S3 allow customers to store and retrieve any amount of data, at anytime from anywhere via internet. The scalable and dynamic of the cloud storage services help their customer to reduce IT administration and maintenance costs. No doubt, cloud based storage services brought a lot of benefits to its customer by significantly reducing cost through optimization increased operating and economic efficiencies. However without appropriate security and privacy solution in place, it could become major issues to the organization. As data get produced, transferred and stored at off premise and multi tenant cloud based storage, it becomes vulnerable to unauthorized disclosure and unauthorized modification. An attacker able to change or modify data while data inflight or when data is stored on disk, so it is very important to secure data during its entire life-cycle. The traditional cryptography primitives for the purpose of data security protection cannot be directly adopted due to user's lose control of data under off premises cloud server. Secondly cloud based storage is not just a third party data warehouse, the data stored in cloud are frequently update by the users and lastly cloud computing is running in a simultaneous, cooperated and distributed manner. In our proposed mechanism we protect the integrity, authentication and confidentiality of cloud based data with the encrypt- then-upload concept. We modified and applied proxy re-encryption protocol in our proposed scheme. The whole process does not reveal the clear data to any third party including the cloud provider at any stage, this helps to make sure only the authorized user who own corresponding token able to access the data as well as preventing data from being shared without any permission from data owner. Besides, preventing the cloud storage providers from unauthorized access and making illegal authorization to access the data, our scheme also protect the data integrity by using hash function.

• 한국컴퓨터정보학회논문지
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• 제22권8호
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• pp.55-61
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• 2017

Cloud computing is cost-effective in terms of system configuration and maintenance and does not require special IT skills for management. Also, cloud computing provides an access control setting where SSO is adopted to secure user convenience and availability. As the SSO user authentication structure of cloud computing is exposed to quite a few external security threats in wire/wireless network integrated service environment, researchers explore technologies drawing on distributed SSO agents. Yet, although the cloud computing access control using the distributed SSO agents enhances security, it impacts on the availability of services. That is, if any single agent responsible for providing the authentication information fails to offer normal services, the cloud computing services become unavailable. To rectify the environment compromising the availability of cloud computing services, and to protect resources, the current paper proposes a security policy that controls the authority to access the resources for cloud computing services by applying the authentication policy of user authentication agents. The proposed system with its policy of the authority to access the resources ensures seamless and secure cloud computing services for users.

• 한국전자거래학회지
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• 제17권1호
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• pp.111-136
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• 2012

세계적인 경제 불황으로 인해 기업의 IT 투자에 대한 부담이 커지고, 녹색 IT에 대한 관심 또한 증대되면서 클라우드 컴퓨팅은 IT 분야에서 전 세계적인 트렌드이자 패러다임이 되었다. 세계 각국의 정부, 기업, 연구소에서 클라우드에 대한 관심과 투자, 연구가 확대되고 있는 실정이며, 국내에서도 2009년부터 본격적인 클라우드 컴퓨팅에 대한 관심이 고조되고 있다. 하지만, 본 연구는 기업이 클라우드 컴퓨팅 서비스 도입에 영향을 미치는 클라우드 컴퓨팅의 특성 요인을 인식하고 관련 이론을 토대로 클라우드 컴퓨팅 서비스의 적극적 도입 및 활용을 위한 이론적 틀을 제시하고 이에 대한 인과관계를 검증하고자 수행 되었다. 연구모형에 포함된 클라우드 컴퓨팅의 특성 요인으로는 확장성, 민첩성, 보안성, 가용성, 효율성, 경제성, 종속성, 신뢰성을 선정하였고, 클라우드 컴퓨팅 서비스 유형의 조절효과를 검증하였다. 클라우드 컴퓨팅에 대한 지식을 보유하고 있고 기업의 IT 의사결정자 또는 의사결정지원자를 대상으로 설문하고 통계적으로 검증한 결과, 효율성, 경제성, 신뢰성 순으로 클라우드 컴퓨팅 서비스 도입에 영향을 미치고 있음을 알 수 있었다. 본 연구의 결과는 아직 연구 초기 단계에 있는 클라우드 컴퓨팅에 대해 고객의 시각에서 바라보고 클라우드 컴퓨팅의 특성에 대한 개념을 정리하여 잠재 고객이나 클라우드 컴퓨팅 서비스를 제공하는 기업, 연구자에게 이를 제공 가능할 것이다.

• 한국정보시스템학회지:정보시스템연구
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• 제25권4호
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• pp.37-61
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• 2016

Purpose This study examines firms at various industries to identify key organizational characteristics that positively drive the evaluation of cloud computing. In addition, this study tests the impact of one's evaluation has on the adoption and integration of cloud computing within their respective firm. Design/methodology/approach A total of 172 responses from various firms currently using cloud computing service were analyzed using the structural equation modeling(SEM). Findings Results show that organizational Needs(Mobility and Job Relevance), Perceived Factors(Relative Advantages and Cost Savings), and Organizational Readiness(Technical Knowledge, Financial Supports, and Managerial Supports) have a significant impact on cloud computing evaluation; and evaluation influences its adoption, and integration. However, two variables(IT Performance Gaps and Compatibility) have no significant impact on cloud computing evaluation. Finally, Evolutional Leadership has a significant moderating effect within the relationship among variables in the process of cloud computing implementation.

• 한국콘텐츠학회논문지
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• 제19권4호
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• pp.79-90
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• 2019

최근 들어 다수의 클라우드 서비스 제공자가 클라우드 컴퓨팅 서비스를 제공함으로써 각 제공자는 더 많은 사용자를 확보하기 위해 치열한 경쟁을 벌이고 있다. 서비스 제공자별 컴퓨팅 자원의 구성 및 서비스 제공 부하가 다르기 때문에 사용자는 다양한 수준의 서비스 품질을 경험할 수 있다. 따라서 클라우드 서비스 시장에서 더 많은 사용자를 확보하여 수익을 최대화하기 위해서는 서비스 품질에 대한 가장 합리적인 가격을 결정하는 것이 매우 중요하다. 본 연구에서는 두 명의 서비스 제공자가 존재하는 멀티미디어 클라우드 서비스 시장에서 두 제공자 간 서비스 가격 경쟁에 대해 다룬다. 두 명의 클라우드 서비스 제공자가 최적의 가격을 결정하여 상호 경쟁하고 자신의 이익을 최대화할 수 있는 가격 산정 방법을 비협력 게임 이론으로 설명한다. 이를 위해 멀티미디어 클라우드 서비스의 제공 프로세스를 대기행렬 시스템으로 모형화하고, 분석 결과를 바탕으로 복점 멀티미디어 클라우드 서비스 시장에서 가격 경쟁 문제를 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권12호
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• pp.2294-2314
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• 2011

The key issue in providing fast and reliable access on cloud services is the effective management of resources in a cloud system. However, the high variation in cloud service access rates affects the system performance considerably when there are no default routines to handle this type of occurrence. Adaptive techniques are used in resource management to support robust systems and maintain well-balanced loads within the servers. This paper presents an adaptive resource management for cloud systems which supports the integration of intelligent methods to promote quality of service (QoS) in provisioning of cloud services. A technique of dynamically assigning cloud services to a group of cloud servers is proposed for the adaptive resource management. Initially, cloud services are collected based on the excess cloud services load and then these are deployed to the assigned cloud servers. The assignment function uses the proposed proportional ordering which efficiently assigns cloud services based on its resource consumption. The difference in resource consumption rate in all nodes is analyzed periodically which decides the execution of service assignment. Performance evaluation showed that the proposed dynamic service assignment (DSA) performed best in throughput performance compared to other resource allocation algorithms.

• The Journal of Asian Finance, Economics and Business
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• 제8권2호
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• pp.833-849
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• 2021

Cloud accounting represents a new area of accounting information systems. Past research has often focused on accounting information systems and its antecedents, rather than factors that adopt cloud accounting system. The purpose of this paper is to explain the factors that influence the adoption of cloud accounting in the financial sectors. This paper applied the technology acceptance model (TAM), technology-organization-environment, and the De Lone and Mc Lean model, coupled with proposed factors relevant to cloud accounting. The proposed model was empirically evaluated using survey data from 187 managers (financial managers, IT department managers, audit managers, heads of accounting departments, and head of internal control departments) in Jordanian bank branches. Based on the SEM results, top management support, organizational competency, service quality, system quality, perceived usefulness, and perceived ease of use had a positive relationship with the intention of using cloud accounting. Cloud accounting adoption positively affected cloud accounting usage. This paper contributes to a theoretical understanding of factors that activate the adoption of cloud accounting. For financial firms in general the results enable them to better develop cloud accounting framework. The paper verifies the factors that affect the adoption of cloud accounting and the proposed cloud accounting model.

• International Journal of Computer Science & Network Security
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• 제22권3호
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• pp.163-172
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• 2022

The interconnection of an enormous number of devices into the Internet at a massive scale is a consequence of the Internet of Things (IoT). As a result, tasks offloading from these IoT devices to remote cloud data centers become expensive and inefficient as their number and amount of its emitted data increase exponentially. It is also a challenge to optimize IoT device energy consumption while meeting its application time deadline and data delivery constraints. Consequently, Fog Computing was proposed to support efficient IoT tasks processing as it has a feature of lower service delay, being adjacent to IoT nodes. However, cloud task offloading is still performed frequently as Fog computing has less resources compared to remote cloud. Thus, optimized schemes are required to correctly characterize and distribute IoT devices tasks offloading in a hybrid IoT, Fog, and cloud paradigm. In this paper, we present a detailed survey and classification of of recently published research articles that address the energy efficiency of task offloading schemes in IoT-Fog-Cloud paradigm. Moreover, we also developed a taxonomy for the classification of these schemes and provided a comparative study of different schemes: by identifying achieved advantage and disadvantage of each scheme, as well its related drawbacks and limitations. Moreover, we also state open research issues in the development of energy efficient, scalable, optimized task offloading schemes for Fog computing.