• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2768-2780
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• 2019

Ciphertext-policy attribute-based encryption (CP-ABE) is one of the practical technologies to share data over cloud since it can protect data confidentiality and support fine-grained access control on the encrypted data. However, most of the previous schemes only focus on data confidentiality without considering data receiver privacy preserving. Recently, Li et al.(in TIIS, 10(7), 2016.7) proposed a CP-ABE with hidden access policy and testing, where they declare their scheme achieves privacy preserving for the encryptor and decryptor, and also has high decryption efficiency. Unfortunately, in this paper, we show that their scheme fails to achieve hidden access policy at first. It means that any adversary can obtain access policy information by a simple decisional Diffie-Hellman test (DDH-test) attack. Then we give a method to overcome this shortcoming. Security and performance analyses show that the proposed scheme not only achieves the privacy protection for users, but also has higher efficiency than the original one.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.4
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• pp.767-779
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• 2013

A field of privacy protection lacks statistical information about the current status, compared to other fields. On top of that, since it has not been classified as a concrete separate field, the related survey is only conducted as a part of such concrete areas. Furthermore, this trend of being regarded as a part of fields such as informatization, information protection and law will continue in the near future. In this paper, a novel and practical way for collecting and storing a big amout of data from 110,000 privacy policies by data controller is proposed and the real analysis results is also shown. The proposed method can save time and cost compared with the traditional survey-based method while maintaining or even advancing the accuracy of results and speediness of process. The collected big personal data can be used to set up various kinds of statistical models and they will play an important role as a breakthrough of observing the present status of privacy information protection policy. The big data concept is incorporated into the privacy protection and we can observe the method and some results throughout the paper.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.2394-2406
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• 2016

ABE has become an effective tool for data protection in cloud computing. However, since users possessing the same attributes share the same private keys, there exist some malicious users exposing their private keys deliberately for illegal data sharing without being detected, which will threaten the security of the cloud system. Such issues remain in many current ABE schemes since the private keys are rarely associated with any user specific identifiers. In order to achieve user accountability as well as provide key exposure protection, in this paper, we propose a key-insulated ciphertext policy attribute based encryption with key exposure accountability (KI-CPABE-KEA). In our scheme, data receiver can decrypt the ciphertext if the attributes he owns match with the self-centric policy which is set by the data owner. Besides, a unique identifier is embedded into each user's private key. If a malicious user exposes his private key for illegal data sharing, his identity can be exactly pinpointed by system manager. The key-insulation mechanism guarantees forward and backward security when key exposure happens as well as provides efficient key updating for users in the cloud system. The higher efficiency with proved security make our KI-CPABE-KEA more appropriate for secure data sharing in cloud computing.

• Journal of Digital Convergence
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• v.18 no.4
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• pp.81-89
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• 2020

Since the Korean privacy policy was legalized in 2011, the related academical researches have been lasted in various fields. Upcoming so-called 3 data laws would be implemented, it is meaningful to review privacy policy studies for exploring future research direction. For this purpose, the total of 146 journals from 2011 to 2019 were reviewed by the content analysis following as research subjects, methodologies and constructions of studies. As results, the numbers of the researches have been conducted on protection policies themselves for improvement, comparing with other countries' policies and also digital finance information protection were deeply discussed. Some of technology based protection applications were experimented and suggested. The major research characteristics was mainly focused on case analysis and criminal laws and policies were developed as protection contingencies. However, most research objects were focused on the protection regulations, not deregulation, therefore, researchers in future study need to explore more digital industry-centric tasks which are practically applied in safer ways. Further, social agreement in using private information will be an essential to prevent indiscriminate use.

• The Journal of Society for e-Business Studies
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• v.25 no.4
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• pp.1-14
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• 2020

IT businesses in Korea have relatively strong regulations. While providing the same service, domestic businesses are in a situation of 'reverse discrimination of regulations' as they are less competitive than global IT companies in accordance with the application of the personal information protection legislation in Korea. In this paper, Personal Information Protection legislation was classified and laws of major countries were analyzed in comparative ways. It also compared and analyzed the "private policy" presented by representative Internet sites (Naver, Daum, Google, Facebook) that provide services to users in Korea. We also proposed three aspects of legislation improvement to address reverse discrimination.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.1
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• pp.323-342
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• 2021

Personal health records (PHRs) is an electronic medical system that enables patients to acquire, manage and share their health data. Nevertheless, data confidentiality and user privacy in PHRs have not been handled completely. As a fine-grained access control over health data, ciphertext-policy attribute-based encryption (CP-ABE) has an ability to guarantee data confidentiality. However, existing CP-ABE solutions for PHRs are facing some new challenges in access control, such as policy privacy disclosure and dynamic policy update. In terms of addressing these problems, we propose a privacy protection and dynamic share system (PPADS) based on CP-ABE for PHRs, which supports full policy hiding and flexible access control. In the system, attribute information of access policy is fully hidden by attribute bloom filter. Moreover, data user produces a transforming key for the PHRs Cloud to change access policy dynamically. Furthermore, relied on security analysis, PPADS is selectively secure under standard model. Finally, the performance comparisons and simulation results demonstrate that PPADS is suitable for PHRs.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.311-318
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• 2013

It is very important to design security policy and technical framework on sensitive private data in order to protect user privacy in smart grid environment. This paper introduces secret data sharing schemes proposed for privacy protection in smart grid, and presents technical problems of them. The proposed scheme in this paper, reduces the number of rounds in sharing process and also in restoration process, and can select how many databases would be used, so eventually it shows enhancements in terms of efficiency and security.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.7
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• pp.475-487
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• 2020

The paper aims to facilitate a discussion around how big data technologies and data from citizens can be used to help public administration, society, and policy-making to improve community's lives. This paper discusses opportunities and challenges of big data strategies for government, society, and policy-making. It employs the presentation of numerous practical examples from different parts of the world, where public-service delivery has seen transformation and where initiatives have been taken forward that have revolutionized the way governments at different levels engage with the citizens, and how governments and civil society have adopted evidence-driven policy-making through innovative and efficient use of big data analytics. The examples include the governments of the United States, China, the United Kingdom, and India, and different levels of government agencies in the public services of fraud detection, financial market analysis, healthcare and public health, government oversight, education, crime fighting, environmental protection, energy exploration, agriculture, weather forecasting, and ecosystem management. The examples also include smart cities in Korea, China, Japan, India, Canada, Singapore, the United Kingdom, and the European Union. This paper makes some recommendations about how big data strategies transform the government and public services to become more citizen-centric, responsive, accountable and transparent.

• Journal of Digital Convergence
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• v.12 no.9
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• pp.153-158
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• 2014

The Collaborative Cloud Storage is that several members of collaborating group together use data stored in a storage. Therefore, it is obvious that it is more complicated and important to protect data stored in the sharing storage than general cloud storage, not Collaborative Cloud Storage. this paper proposes a method for user authentication and data protection.

• Health Policy and Management
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• v.6 no.2
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• pp.1-13
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• 1996

To evalate the efficiency of public and private hospitals, the author used Data Envelopment Analysis(DEA), a mathematical linear programming method calculating the of ficiency of a unity(DMU: Decision Making Unit) in relation to the other units in analysis. DEA was applied to thirty three (10 public and 23 private) general hospitals wiwith 160 to 299 beds. In respect to productivity, public hospitals appeared to be a little more efficient than private ones, even though it's statisticansignificant. However, the efficiency score for profitability conversed that these contrary results were due to the caring of more medical protection patients in public hospitals, who brought less revenlue to te hospital than other patients. Public hospitals' superiority to private counterparts in productivity, which are aguged mainly based on cared patients, suggests that the former contributes so much positively to social utility. In particular, the fact that public hospitals are caring more medical protection patients, namely the poverty group whom the society should bear a burden of by all means, seems to be desirable in respect of role of publi hospitals.