• Journal of KIISE:Information Networking
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• v.36 no.3
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• pp.184-190
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• 2009

WiBro has advantages when both WLAN and 3G UMTS are adopted. Much research is being carried out in this area. However, the WiBro specification does not consider end-to-end security. Hence, another security protocol has to be adopted to support secure communication. Most previous research only focused on WiBro MAC performance improvement or security. In this paper, we adopt a security protocol such as IPsec, TLS, and DTLS, well known end-to-end security protocols, to make full use of WiBro in the IP network. Using NS-2 we simulated the adoption of end-to-end security protocol and evaluated performance and usability. Simulation shows DTLS had some performance advantages. All the protocols, TLS and IPsec are also suitable for use in WiBro.

• ETRI Journal
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• v.42 no.1
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• pp.138-149
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• 2020

In this paper, we describe a simultaneously transmitted jamming (ST-jamming) for bi-directional in-band full-duplex (IFD) system to improve information security at the physical layer. By exploiting ST-jamming, each legitimate user transmits data samples and jamming samples together in one orthogonal frequency division multiplexing symbol according to given traffic asymmetry. Regardless of the traffic difference in both directions in IFD communication, eavesdropping of confidential information is prevented in both directions simultaneously without the loss of data rate. We first propose an encoding scheme and the corresponding decoding scheme for ST-jamming to be used by the legitimate users. In addition, we study a transceiver structure of the legitimate users including a baseband modem uniquely designed for the use of ST-jamming. The leakage of confidential information at an eavesdropper is then quantified by studying the mutual information between the confidential transmit signals and the received signals of the eavesdropper. Simulation results show that the proposed ST-jamming significantly reduces the leakage of legitimate information at the eavesdropper.

• International Journal of Computer Science & Network Security
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• v.24 no.9
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• pp.41-49
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• 2024

This paper proposes dual symbol superposition block carrier transmission with frequency domain equalization (DSS-FDE) system. This system is based upon χ-transform matrix, which is obtained by concatenation of discrete Hartley transform (DHT) matrix and discrete Fourier transform (DFT) matrices into single matrix that is remarkably sparse, so that, as it will be shown in this paper, it only has non-zero entries on its principal diagonal and one below the principle anti-diagonal, giving it shape of Latin alphabet χ. When multiplied with constellation mapped complex transmit vector, each entry of resultant vector is weighted superposition of only two entries of original vector, as opposed to all entries in conventional DFT based OFDM. Such a transmitter is close to single carrier block transmission with frequency domain equalization (SC-FDE), which is known to have no superposition. The DSS-FDE offers remarkable simplicity in transmitter design and yields great benefits in reduced complexity and low PAPR. At receiver-end, it offers the ability to harvest full diversity from multipath fading channel, full coding gain, with significant bit error rate (BER) improvement. These results will be demonstrated using both analytical expressions, as well as simulation results. As will be seen, this paper is Part III of three-paper series on alternative transforms for multicarrier communication (MC) systems.

• Korean Security Journal
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• no.62
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• pp.295-320
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• 2020

The purpose of this study is to analyze the influence which affects security performance of registered security guards hired by government buildings via job engagement so that basic data can be provided to improve their security performance. To accommodate this study, a survey was conducted from November 26th to December 27th, 2019 through the cooperation of registered security guards working in government buildings in Seoul, Gwacheon, Daejeon, and Sejong. A total of 234 survey sheets were collected and 28 sheets out of them had missing data or incomplete data so a subsequent total of 206 survey sheets were used in this analysis. SPSS 23.0 was applied making use of the collected data for frequency and descriptive statistics analysis, trustworthiness analysis, exploratory factor analysis, and correlation analysis. By applying AMOS 23.0, a means to examine the structural relation between organization, job engagement, and security performance were able to be analyzed. The result of this study is as follows. First, it was found that organizational justice gives a meaningful positive (+) influence on job engagement for registered security guards. Second, it was found that job engagement for registered security guards gives them a meaningful positive(+) influence in their security performance. Third, it was found that organizational justice does not give any meaningful influence on security performance directly. Fourth, organizational justice does not give any meaningful influence on security performance directly but it gives meaningful positive(+) influence on security performance via job engagement as it takes the role of full mediation variable. Based on the results, in order to maximize security performance of registered security guards, this study recommends that government building administrators to try their best to propose to the National Assembly a proposition for Police Assigned for registered security guards Act to be legalized in order to improve the leveling system of registered security guards so that registered security guards can have more job engagement.

• Korean Security Journal
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• no.15
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• pp.243-264
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• 2008

Recently the private security industry is showing rapid growth compared with the different types of industry. However, it is not prepared the device for the system to verify the professional qualification of the security guards. To protect individual life and property, body and security guards have to be qualified professionally. For it the role of professional qualification systems is emphasized. The problem of the certification of the qualification about the security guard to play the role to protect a body / life of the individual and property are the part to need necessarily as the quality problem of the individual and the trust of the people. The settlement of the qualification system which is such system can induce the development of the security industry with social trust. The certified security certification is needed and how to control the security quality to get better service to the clients. The professional qualification system to be carrying out with America and Japan is fixed through the cooperation of the business world and steady research for the qualification system plan, these are giving the trial of the qualification system of a security of Korea full of the suggestion. This study will do this to the basis which a necessity about the qualification system of the security man emphasis and considerate professional qualification system concerning the private security development plan around the Bodyguard Qualifying Examination which are carried out at twice by the Korea Security Association and the Korean Institute of Security. In summary to meet the social demand professional qualification for the security guards will be drawn from the analyses of civil security qualification systems.

• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.215-225
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• 2011

This paper suggests several methods of improving information securities of universities through the investigations of the current status of information securities in universities, which is becoming a hot topic in knowledge and information societies. In this paper, universities were randomly selected according to their size, and surveyed through email questionnaire to the persons in charge of security in each university, and 27 universities and 18 colleges were replied. From the survey results we confirmed that the pre-prevention is the most important thing in securing information assets, also in universities, and, in this paper, systematic support must be strengthened to establish a comprehensive security management policy and guidelines for the universities, and the importance of information assets and the necessity of security needs to be shared with the members in the universities. Moreover there must be full administrative and financial support, including recruitment and training of information security professionals and the establishing a separate security division.

• Convergence Security Journal
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• v.14 no.3_2
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• pp.3-12
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• 2014

The government was fully aware of the gravity of a recent massive leak of personal information of credit card users. Meanwhile, the government just took a light disciplinary action by imposing a fine, but it showed its intention to strengthen the regulations by taking the severest disciplinary action. The tightened regulations against personal information leak will be applied to the private security industry without exception to protect individual people's property and lives if such an incident occurs in that industry that deals with a wide variety of personal information such as CCTV data or privacy information all the time. The purpose of this study was to examine the state of the protection and management of personal information for service users among private security firms in an effort to suggest some reform measures. The findings of the study were as follows: First, administrators or managers who are involved with personal information protection should make a full-fledged effort to gather information. Second, counseling or related programs should be provided for small and mid-sized security firms to guarantee thorough personal information protection. Third, Korea Security Association should improve the educational system related to personal information protection to resolve problems with this education currently provided for managers and employees of these companies.

• Convergence Security Journal
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• v.9 no.4
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• pp.7-12
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• 2009

It is very difficult to completely block the DDoS attack, which paralyzes services by depleting resources or occupying the network bandwidth by transmitting a vast amount of traffic to the specific website or server from normal users' PCs that have been already infected by an outside attacker. In order to defense or endure the DDoS attack, we usually use various solutions such as IDS (Intrusion Detection System), IPS (Intrusion Prevention System), ITS (Intrusion Tolerance System), FW (Firewall), and the dedicated security equipment against DDoS attack. However, diverse types of security appliances cause the cost problem, besides, the full function of the equipments are not performed well owing to the unproper setting without considering connectivity among systems. In this paper, we present the effective connectivity of security equipments and countermeasure methodology against DDoS attack. In practice, it is approved by experimentation that this designed methdology is better than existing network structure in the efficiency of block and endurance. Therefore, we would like to propose the effective security control measures responding and enduring against discriminated DDoS attacks through this research.

• Korean Journal of Optics and Photonics
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• v.14 no.6
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• pp.623-629
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• 2003

In this paper, we have proposed a full phase encryption scheme based on phase-encoded XOR operation. The proposed scheme encrypts a gray-level image by slicing an original image and combining with XORed images which resulted from phase-encoded XOR operations between sliced images and phase-encoded binary random images. Then we produce an encrypted image by combining only XORed images and a key image by only phase-encoded binary random images. The encrypted image and key image are converted into encrypted data and key data by a phase-encoding method. The merits are that the proposed encryption scheme can basically fulfill a high-level encryption using a full phase encryption scheme which has nonlinear and invisible characteristics. The scheme also improves security by encrypting the phase information before full phase encryption. The decryption system based on the principle of interference between a reference wave and a direct pixel-to-pixel mapping image of encrypted data with key data can be simply implemented using a phase-visualization system. Simulation results indicate that our proposed encryption scheme is effective and simple for a gray-scale image and optical decryption system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.3
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• pp.75-84
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• 2004

In this paper, we present a related key differential attack on Full-round GOST Firstly, we present a distinguishing attack on full rounds of GOST, which can distinguish it from random oracle with probability 1- 64$2^{64}$ using a related key differential characteristic. We will also show that H. Seki et al.'s idea can be applied to attack on 31 rounds of GOST combining our related key differential characteristic. Lastly, we propose a related key differential attack on full rounds of GOST. In this attack we can recover 12 bits of the master key with $2^{35}$ chosen plaintexts and $2^{36}$ encryption times for the 91.7% expectation of success rate.