• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.10
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• pp.1849-1854
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• 2017

Recently, RF energy harvesting, in which energy is collected from the external RF signals, is considered as a promising technology to resolve the energy shortage problem of wireless sensors. In addition, it is important to guarantee secure communication between sensors for implementing Internet-of-Things. In this paper, we propose a power splitting-based network analog coding for maximizing a physical layer security in 2-hop networks where the wireless-powered relay can harvest energy from the signals transmitted by two sources. We formulate systems where two sources, relay, and eavesdropper exist, and find an optimal power splitting ratio for maximizing the minimum required secrecy capacity using an exhaustive search. Through simulations under various environments, it is demonstrated that the proposed scheme improves the minimum required secrecy capacity by preventing the eavesdropper from overhearing source signals, compared to the conventional scheme.

• Journal of KIISE:Databases
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• v.27 no.1
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• pp.42-52
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• 2000

In many real time applications that the system maintains sensitive information to be shared by multiple users with different security levels, security is another important requirement. A secure real time database system must satisfy not only logical data consistency but also timing constrains and security requirements associated with transactions. Even though an optimistic concurrency control method outperforms locking based method in firm real time database systems, where late transactions are immediately discarded, most existing secure real time concurrency control methods are based on locking. In this paper, we propose a new optimistic concurrency control protocol for secure real time database systems, and compare the performance characteristics of our protocol with locking based method while varying workloads. The result shoes that our proposed O.C.C protocol has good performance in case of many data conflict.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.3
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• pp.501-507
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• 2015

The online banking service handles a banking business over the internet, it is necessary to ensure that all financial transactions are processed securely. So, there are various authentication technique for e-banking service : a certificate, a personal identification number(PIN), a security card and a one-time password(OTP). Especially, the security card is most important means including secret information. If the secret information of card is leaked, it means not only loss of security but also easy to attack because security card is a difficult method to get. In this paper, we propose that a multi-channel security card saves an secret information in distributed channel. Proposed multi-channel security card reduces vulnerability of the exposed and has a function to prevent phishing attacks through decreasing the amount of information displayed and generating secret number randomly.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.747-751
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• 2013

Researches on U-Healthcare service integrating medical information and IT technologies are actively conducted. U-Healthcare service is the next generation's medical paradigm that ensures conveniences to many users so that the society recognizes the importance and attempts for commercialization through various business model are performed. To form such U-Healthcare service market safely, various policies on the social structure should be established through the standard and the medical law to systemize of the medical information led by the governmen. Especially, the government's security policy to ensure the safety for the government leading visualization of U-Healthcare should be firmly established. Firstly, this paper presents U-healthcare Service and policy guideline. Secondly, it analyzes security threatening factors for the safe U-Healthcare service. By classifying the analyzed security threatening factors based on three major elements of the security, Confidentiality, Integrity and Availability of security policy for each element is proposed.

• Journal of the Korea Convergence Society
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• v.8 no.6
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• pp.37-44
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• 2017

Mobile devices provide various services through payment and authentication by inputting important information such as passwords on the screen with the virtual keypads. In order to infer the password inputted by the user, the attacker captures the user's touch location information. The attacker is able to infer the password by using the location information or to obtain password information by peeping with Google Glass or Shoulder Surfing Attack. As existing secure keypads place the same letters in a set order except for few keys, considering handy input, they are vulnerable to attacks from Google Glass and Shoulder Surfing Attack. Secure keypads are able to improve security by rearranging various shapes and locations. In this paper, we propose secure keypads that generates 13 different shapes and sizes of Tetris and arranges keypads to be attached one another. Since the keypad arranges different shapes and sizes like the game, Tetris, for the virtual keypad to be different, it is difficult to infer the inputted password because of changes in size even though the attacker knows the touch location information.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.3
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• pp.705-715
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• 2017

Today, the world is evolving into a huge community that can communicate with real-time information sharing and communication based on the rapid advancement of scientific technology and information. Behind this information, the adverse effects of information assets, such as hacking, viruses, information assets, and unauthorized disclosure of information assets, are continually increasing as a serious social problem. Each time an infringement of the invasion and personal information leaks occur, many regulatory policies have been announced, including stricter regulations for protecting the privacy of the government and establishing comprehensive countermeasures. Also, companies are making various efforts to increase awareness of the importance of information security. Nevertheless, information security accidents like the leaks of industrial secrets are continuously occurring and the frequency is not lessening. In this thesis, I proposed a customized security policy methodology that supports users with various business circumstances and service and also enables them to respond to the security threats more confidently and effectively through not a monotonous and technical but user-centered security policy.

• The KIPS Transactions:PartC
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• v.10C no.6
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• pp.675-682
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• 2003

Attackers collect vulnerabilities of a target computer system to intrude into it. And using several attack methods, they acquire root privilege. They steal and alter information in the computer system, or destroy the computer sysem. So far many intrusion detection systems and firewallshave been developed, but recently attackers go round these systems and intrude into a computer system . In this paper, we propose security kernel module to prevent attackers having acquired root privilege from doing illegal behaviors. It enhances administrator authentication with additional password, so prevents attackers from doing illegal behaviors such as modification of important files and installation of rootkits. It sends warning mail about sttacker's illegal behaviors to administrators by real time. So using information in the mail, they can estabilish new security policies.

• Smart Media Journal
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• v.8 no.4
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• pp.17-24
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• 2019

As IoT technology is widely used in industrial environments, its environmental security issues are becoming more important. In such a context, studies utilizing hardware security functions are being actively carried out. However, previous studies did not consider the performance degradation that occurs when using hardware security functions in IoT environment. Gateway devices that are mainly used in IoT environments are often resource-limited. Utilizing hardware security in such an environment can cause serious performance degradation as the number of IoT devices connected to the gateway increases. Therefore, in this paper, we propose a data classification scheme to efficiently utilize hardware security functions in resource limited environment. We implement a platform with the proposed technique using ARM Trustzone. Performance degradation due to the hardware security functions is measured through experiments on the implemented platform and compared with the performance as of when the proposed technique is applied.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.307-310
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• 2010

Ubiquitous society to build basic infrastructure in the power supply and power equipment safety is important. U-City in order to prevent the disaster of U-IT Power Equipment Performance Module and the security for the safety of the U-City is necessary. In this paper, the power unit of U-IT module, temperature sensor, humidity sensor, equipped with sensors arranged throughout the fire, and home distribution boards, Home Network Wall-Pad, Blocker, MPNP black boxes, arc detection, arc safety equipment, outlet of the modular performance evaluation and security measures will be studied. U-IT power devices and sensors to analyze the information conveyed by proactive risk and ensure safety, access control, authentication, security safeguards, such as U-IT integrated management system for electrical safety and strengthen the security, safety and security with a U-City will contribute to the construction and operation.

• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.741-756
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• 2001

With the development of computer systems, there has been a sharp increase in the threats on these systems including attacks by malicious programs such as virus, vandal, etc. Currently virus vaccines are widely used to thwart these threats, but they have many weaknesses. They cannot guard against unknown threats and sometimes, they also cannot detect the existence of malicious programs before these malicious programs make any destructive results. For lack of an efficient security model, the existing security programs have the problem that they raise many false-positive alarms in spite of normal action. So it becomes very important to develop the improved security program that can make up for the weakness of the existing computer security program and can detect many threats of malicious programs as early as possible. In this paper we describe the design of an improved security model and the implementation of a security program that can filter and handle the threats on computer systems at the kernel level in real time.