• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.131-134
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• 2014

The Internet allows firms to serve customers more effectively than ever before. In the B2C context, we examine the interrelationships among information privacy concerns, e-trust, and e-loyalty. The authors extend prior research by incorporating constructs of information privacy concerns into a more holistic conceptual framework. This study answers three research questions: Will the three components of information privacy concerns have a significant effect on e-loyalty through e-trust?, Does e-trust mediate e-loyalty?, Finally, do switching costs have a moderation effect between e-trust and e-loyalty?, The authors examine data from customers who have booked hotel accommodations online. The results support our hypotheses and confirm both the mediation role of e-trust and the moderation role of switching costs. Conceptually, this study provides an empirical validation of information privacy concerns, e-trust, and loyalty linkage. On the managerial level, this research provides insights into critical drivers of loyalty in the emerging online marketplace.

• Journal of the Korea Society of Computer and Information
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• v.28 no.1
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• pp.171-178
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• 2023

As the risk of privacy invasion due to self-disclosure increases in SNS environment, many studies have tried to discover the influencing factors of self-disclosure. This study is an extension of this research stream and pays attention to the role of interaction privacy controls(friend list and privacy settings) as a new influencing factor. Specifically, the study theorizes and test the logic that the ability to effectively control interactions between individuals using IPC(called IPC usefulness) satisfies the three psychological needs(autonomy, relationship, and competency needs) suggested by the Self-Determination Theory, and in turn increase the amount of self-disclosure. As a result of data analysis, it was found that IPC usefulness has a very strong influence on the satisfaction of psychological needs and is a major factor in increasing the degree of self-disclosure by users. Based on these findings, the study discusses the theoretical and practical implications as well as future research directions.

• Journal of Korea Multimedia Society
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• v.22 no.5
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• pp.613-625
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• 2019

The rise of the Internet of Things (IoT) devices have greatly influenced many industries and one of them is healthcare where wearable devices started to track all your daily activities for better health monitoring accuracy and even down to tracking daily food intake in some cases. With the amounts of data that are being tracked and shared between from these devices, questions were raised on how to uphold user's data privacy when data is shared between these IoT devices and third party. With the blockchain platforms started to mature since its inception, the technology can be implemented according to a variety of use case scenarios. In this paper, we present a system architecture based on the healthcare system and IoT network by leveraging on multiple blockchain networks as the medium in between that should enable users to have direct authority on data accessibility of their shared data. We provide proof of concept implementation and highlight the results from our testing to show how the efficiency and scalability of the healthcare system improved without having a significant impact on the performance of the Electronic Medical Record (EMR) that mostly affected by the previous solution since these solutions directly connected to a public blockchain network and which resulted in significant delays and high cost of operation when a large amount of data or complicated functions are involved.

• The Journal of Bigdata
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• v.5 no.2
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• pp.43-52
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• 2020

With the development of data technology, storing and sharing of data has increased, resulting in privacy invasion. Although de-identification technology has been introduced to solve this problem, it has been proved many times that identifying individuals using de-identified data is possible. Even if it cannot be completely safe, sufficient de-identification is necessary. But current laws and regulations do not quantitatively specify the degree of how much de-identification should be performed. In this paper, we propose an appropriate de-identification criterion considering the time required for re-identification. We focused on the case of using the k-anonymity model among various privacy models. We analyzed the time taken to re-identify data according to the change in the k value. We used a re-identification method based on linkability. As a result of the analysis, we determined which k value is appropriate. If the generalized model can be developed by results of this paper, the model can be used to define the appropriate level of de-identification in various laws and regulations.

• Journal of Information Technology Services
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• v.21 no.1
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• pp.1-19
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• 2022

With the revision of the Credit Information Use and Protection Act in August 2020, the MyData service based on open banking policy will take effect in January 2022. Nonetheless, the previous studies focused on the legal system or security-related issues of such service. Therefore, this paper conducted an empirical study on financial consumers aged 20 or older nationwide to analyze the factors which influence the intention to use MyData services based on open banking. Five characteristics representing open banking-based MyData service were derived through prior research, and a research model that combined value-based adoption model and privacy calculus theory was presented. The proposed research model and the relationship of its variables was analyzed using a sample of 400 users that is randomly selected. The results of empirical analysis showed that personalization had the greatest influence on benefits and reliability on sacrifice among service characteristics. They also suggested that MyData operators should devote themselves to providing customized services optimized for customers and establishing trust relationships. It was confirmed that both usefulness and enjoyment had a great influence on perceived value, and in terms of sacrifice, the burden of financial costs had a greater influence than privacy concerns. This study is meaningful in that it explored the psychological propensity of financial consumers to identify service utilization factors and presented a new approach that can contribute to the successful settlement of the domestic MyData industry.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.8
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• pp.259-268
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• 2022

With prosperous usage of cloud services to improve management efficiency due to the explosive increase in data volume, various cryptographic techniques are being applied in order to preserve data privacy. In spite of the vast computing resources of cloud systems, decrease in storage efficiency caused by redundancy of data outsourced from multiple users acts as a factor that significantly reduces service efficiency. Among several approaches on privacy-preserving data deduplication over encrypted data, in this paper, the research results for improving efficiency of encrypted data deduplication using trusted execution environment (TEE) published in the recent USENIX ATC are analysed in terms of security and efficiency of the participating entities. We present a way to improve the stability of a key-managing server by integrating it with individual clients, resulting in secure deduplication without independent key servers. The experimental results show that the communication efficiency of the proposed approach can be improved by about 30% with the effect of a distributed key server while providing robust security guarantees as the same level of the previous research.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.9
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• pp.305-316
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• 2022

With the flood of digital data owing to the Internet of Things and big data, cloud service providers that process and store vast amount of data from multiple users can apply duplicate data elimination technique for efficient data management. The user experience can be improved as the notion of edge computing paradigm is introduced as an extension of the cloud computing to improve problems such as network congestion to a central cloud server and reduced computational efficiency. However, the addition of a new edge device that is not entirely reliable in the edge computing may cause increase in the computational complexity for additional cryptographic operations to preserve data privacy in duplicate identification and elimination process. In this paper, we propose an efficiency-improved duplicate data elimination protocol while preserving data privacy with an optimized user-edge-cloud communication framework by utilizing a trusted execution environment. Direct sharing of secret information between the user and the central cloud server can minimize the computational complexity in edge devices and enables the use of efficient encryption algorithms at the side of cloud service providers. Users also improve the user experience by offloading data to edge devices, enabling duplicate elimination and independent activity. Through experiments, efficiency of the proposed scheme has been analyzed such as up to 78x improvements in computation during data outsourcing process compared to the previous study which does not exploit trusted execution environment in edge computing architecture.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5560-5579
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• 2019

Searchable symmetric encryption (SSE) scheme can perform search on encrypted data directly without revealing the plain data and keywords. At present, many constructive SSE schemes were proposed. However, they cannot really resist the malicious adversary, because it (i.e., the cloud server) may delete some important data. As a result, it is very likely that the returned search results are incorrect. In order to better guarantee the integrity of outsourcing data, and ensure the correction of returned search results at the same time, in this paper, we combine SSE with blockchain (BC), and propose a SSE-on-BC framework model. We then construct two concrete schemes based on the size of the data, which can better provide privacy protection and integrity verification for data. Lastly, we present their security and performance analyses, which show that they are secure and feasible.

• Journal of KIISE
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• v.43 no.12
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• pp.1437-1457
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• 2016

In outsourced databases, the cloud provides an authorized user with querying services on the outsourced database. However, sensitive data, such as financial or medical records, should be encrypted before being outsourced to the cloud. Meanwhile, k-Nearest Neighbor (kNN) query is the typical query type which is widely used in many fields and the result of the kNN query is closely related to the interest and preference of the user. Therefore, studies on secure kNN query processing algorithms that preserve both the data privacy and the query privacy have been proposed. However, existing algorithms either suffer from high computation cost or leak data access patterns because retrieved index nodes and query results are disclosed. To solve these problems, in this paper we propose a new kNN query processing algorithm on the encrypted database. Our algorithm preserves both data privacy and query privacy. It also hides data access patterns while supporting efficient query processing. To achieve this, we devise an encrypted index search scheme which can perform data filtering without revealing data access patterns. Through the performance analysis, we verify that our proposed algorithm shows better performance than the existing algorithms in terms of query processing times.

• Journal of KIISE
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• v.44 no.10
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• pp.1112-1123
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• 2017

As content providers further offload content-centric services to the cloud, data retrieval over the cloud typically results in many redundant items because there is a prevalent near-duplication of content on the Internet. Simply fetching all data from the cloud severely degrades efficiency in terms of resource utilization and bandwidth, and data can be encrypted by multiple content providers under different keys to preserve privacy. Thus, locating near-duplicate data in a privacy-preserving way is highly dependent on the ability to deduplicate redundant search results and returns best matches without decrypting data. To this end, we propose an efficient near-duplicate detection scheme for encrypted data in the cloud. Our scheme has the following benefits. First, a single query is enough to locate near-duplicate data even if they are encrypted under different keys of multiple content providers. Second, storage, computation and communication costs are alleviated compared to existing schemes, while achieving the same level of search accuracy. Third, scalability is significantly improved as a result of a novel and efficient two-round detection to locate near-duplicate candidates over large quantities of data in the cloud. An experimental analysis with real-world data demonstrates the applicability of the proposed scheme to a practical cloud system. Last, the proposed scheme is an average of 70.6% faster than an existing scheme.