• ETRI Journal
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• v.34 no.1
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• pp.66-75
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• 2012

This paper proposes a privacy-preserving database encryption scheme that provides access pattern hiding against a service provider. The proposed scheme uses a session key to permute indices of database records each time they are accessed. The proposed scheme can achieve access pattern hiding in situations in which an adversary cannot access the inside of the database directly, by separating the entity with an index table and data table and permuting both the index and position where the data are stored. Moreover, it is very efficient since only O(1) server computation and communication cost are required in terms of the number of the data stored. It can be applied to cloud computing, where the intermediate entities such as cloud computing service provider can violate the privacy of users or patients.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.3
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• pp.625-633
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• 2018

Realm is an open source database developed to replace SQLite, which is commonly used in mobile devices. The data stored in the database must be checked during the digital forensic analysis process for mobile devices because it can help to understand the behavior of the user and whether the mobile device is operating or not. In addition, since the user can intentionally use anti-forensic techniques such as deleting data stored in the database, research on how to recover deleted records is needed. In this paper, we propose a method to recover records that have not been overwritten after deletion based on the analysis of the structure and record and deletion process of the Realm database file.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.990-992
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• 2011

In this paper, we introduce a new Tabu method to get K-anonymity character in database information privacy protection. We use the conception of lattice to form the solution space for K-anonymity Character and search the solution area in this solution space to achieve the best or best approach modification solution for the information in the database. We then compared the Tabu method with other traditional heuristic method and our method show a better solution in most of the cases.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.7
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• pp.3375-3400
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• 2018

With the advent of database-as-a-service (DAAS) and cloud computing, more and more data owners are motivated to outsource their data to cloud database in consideration of convenience and cost. However, it has become a challenging work to provide security to database as service model in cloud computing, because adversaries may try to gain access to sensitive data, and curious or malicious administrators may capture and leak data. In order to realize privacy preservation, sensitive data should be encrypted before outsourcing. In this paper, we present a secure and practical system over encrypted cloud data, called QSDB (queryable and secure database), which simultaneously supports SQL query operations. The proposed system can store and process the floating point numbers without compromising the security of data. To balance tradeoff between data privacy protection and query processing efficiency, QSDB utilizes three different encryption models to encrypt data. Our strategy is to process as much queries as possible at the cloud server. Encryption of queries and decryption of encrypted queries results are performed at client. Experiments on the real-world data sets were conducted to demonstrate the efficiency and practicality of the proposed system.

• International Journal of Computer Science & Network Security
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• v.22 no.1
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• pp.97-104
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• 2022

In recent years, data privacy has become increasingly important. The goal of network cryptography is to protect data while it is being transmitted over the internet or a network. Social media and smartphone apps collect a lot of personal data which if exposed, might be damaging to privacy. As a result, sensitive data is exposed and data is shared without the data owner's consent. Personal Information is one of the concerns in data privacy. Protecting user data and sensitive information is the first step to keeping user data private. Many applications user data can be found on other websites. In this paper, we discuss the issue of privacy and suggest a mechanism for keeping user data hidden in other applications.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.9-17
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• 2009

RFID (Radio Frequency Identification) is a next generation technology that will replace barcode. RFID can identify an object by reading ID inside a RFID tag using radio frequency. However, because a RFID tag replies its unique ID to the request of any reader through wireless communication, it is vulnerable to attacks on security or privacy through wiretapping or an illegal reader's request. The RFID authentication protocol has been studied actively in order to solve security and privacy problems, and is used also in tag search. Recently, as the number of tags is increasing in RFTD systems and the cost of data collection is also rising, the importance of effective tag search is increasing. This study proposed an efficient search method that solved through ta9 group the problem of large volume of database computation in Miyako Ohkubo's hash chain mechanism, which meets requirements for security and privacy protection. When we searched first the group of tags with access rate of 5 or higher in a database with 100,000 records, search time decreased by around 30%.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.65-74
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• 2021

Digital image processing and retrieving have increasingly become very popular on the Internet and getting more attention from various multimedia fields. That results in additional privacy requirements placed on efficient image matching techniques in various applications. Hence, several searching methods have been developed when confidential images are used in image matching between pairs of security agencies, most of these search methods either limited by its cost or precision. This study proposes a secure and efficient method that preserves image privacy and confidentially between two communicating parties. To retrieve an image, feature vector is extracted from the given query image, and then the similarities with the stored database images features vector are calculated to retrieve the matched images based on an indexing scheme and matching strategy. We used a secure content-based image retrieval features detector algorithm called Speeded-Up Robust Features (SURF) algorithm over public cloud to extract the features and the Honey Encryption algorithm. The purpose of using the encrypted images database is to provide an accurate searching through encrypted documents without needing decryption. Progress in this area helps protect the privacy of sensitive data stored on the cloud. The experimental results (conducted on a well-known image-set) show that the performance of the proposed methodology achieved a noticeable enhancement level in terms of precision, recall, F-Measure, and execution time.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.11a
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• pp.366-368
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• 2011

In this paper, we introduce a new kind of expressions for privacy protection techniques in database, such as K-anonymity L-diversity and t-closeness. With such kind of expressions, we provide a new way to solve the privacy protection problems, such as Linear programming, Non-linear programming, Integer programming and so on. Also most of the heuristic techniques are also efficient to be adopted under the expressions given.

• Journal of KIISE
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• v.42 no.5
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• pp.652-663
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• 2015

Due to the popularity of location-based services, the amount of generated spatial data in daily life has been dramatically increasing. Therefore, spatial database outsourcing has become popular for data owners to reduce the spatial database management cost. The most important consideration in database outsourcing is meeting the privacy requirements and guarantying the integrity of the query result. However, most of existing database transformation techniques do not support both of the data privacy and integrity of the query result. To solve this problem, we propose a spatial data transformation scheme that utilizes the shearing transformation with rotation shifting. In addition, we described the attack models to measure the data privacy of database transformation schemes. Finally, we demonstrated through the experimental evaluations that our scheme provides high level of data protection against different kinds of attack models, compared to the existing schemes, while guaranteeing the integrity of the query result sets.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.364-374
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• 2022

Health information systems (HIS) are facing security challenges on data privacy and confidentiality. These challenges are based on centralized system architecture creating a target for malicious attacks. Blockchain technology has emerged as a trending technology with the potential to improve data security. Despite the effectiveness of this technology, still HIS are suffering from a lack of data privacy and confidentiality. This paper presents a blockchain-based data storage security architecture integrated with an e-Health care system to improve its security. The study employed a qualitative research method where data were collected using interviews and document analysis. Execute-order-validate Fabric's storage security architecture was implemented through private data collection, which is the combination of the actual private data stored in a private state, and a hash of that private data to guarantee data privacy. The key findings of this research show that data privacy and confidentiality are attained through a private data policy. Network peers are decentralized with blockchain only for hash storage to avoid storage challenges. Cost-effectiveness is achieved through data storage within a database of a Hyperledger Fabric. The overall performance of Fabric is higher than Ethereum. Ethereum's low performance is due to its execute-validate architecture which has high computation power with transaction inconsistencies. E-Health care system administrators should be trained and engaged with blockchain architectural designs for health data storage security. Health policymakers should be aware of blockchain technology and make use of the findings. The scientific contribution of this study is based on; cost-effectiveness of secured data storage, the use of hashes of network data stored in each node, and low energy consumption of Fabric leading to high performance.