• International Journal of Computer Science & Network Security
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• v.21 no.9
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• pp.339-345
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• 2021

The rapid development of various applications in networking system, business, medical, education, and other domains that use basic data access operations such as insert, edit, delete and search makes data structure venerable and crucial in providing an efficient method for day to day operations of those numerous applications. One of the major problems of those applications is achieving constant time to search a key from a collection. A number of different methods which attempt to achieve that have been discovered by researchers over the years with different performance behaviors. This work evaluated these methods, and found out that almost all the existing methods have non-constant time for adding and searching a key. In this work, we designed a multi-indexes hashing algorithm that handles a collision in a hash table T efficiently and achieved constant time O(1) for searching and adding a key. Our method employed two-level of hashing which uses pattern extraction h₁(key) and h₂(key). The second hash function h₂(key) is use for handling collision in T. Here, we eliminated the wasted slots in the search space T which is another problem associated with the existing methods.

• International Journal of Computer Science & Network Security
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• v.21 no.3
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• pp.304-310
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• 2021

The paper presents problems of optimization of the synthesis of embedded systems, in particular Pareto optimization. The model of such a system for its design for high-level of abstract is based on the classic approach known from the theory of task scheduling, but it is significantly extended, among others, by the characteristics of tasks and resources as well as additional criteria of optimal system in scope structure and operation. The metaheuristic algorithm operating according to this model introduces a new approach to system synthesis, in which parallelism of task scheduling and resources partition is applied. An algorithm based on a genetic approach with simulated annealing and Boltzmann tournaments, avoids local minima and generates optimized solutions. Such a synthesis is based on the implementation of task scheduling, resources identification and partition, allocation of tasks and resources and ultimately on the optimization of the designed system in accordance with the optimization criteria regarding cost of implementation, execution speed of processes and energy consumption by the system during operation. This paper presents examples and results for multi-criteria optimization, based on calculations for specifying non-dominated solutions and indicating a subset of Pareto solutions in the space of all solutions.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.4
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• pp.131-142
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• 2010

Due to the development of the Internet, Internet banking that we are liberated from time and space has evolved into banking system. So modern life became comfortable. However, Dysfunction (malicious Information leakage and hacking etc.) of the Internet development has become a serious social problem. According to this, The need for security is rapidly growing. In this paper, we proposed the Internet Banking Authentication System using a dual-channel in OTP(One Time Password) authentication. This technology is that A user transfer transaction information to Bank through one Internet channel then bank transfer transaction information to user using the registered mobile phone or smart phone. If user confirm transaction information then bank request user's OTP value. User create OTP value and transfer to bank and bank authenticate them throgth the ARS. If authentication is pass then transaction permitted. Security assessment that the proposed system, the security requirement that the confidentiality and integrity, authentication, repudiation of all of the features provide a key length is longer than the current Internet banking systems, such as using encryption, the security provided by the Financial Supervisory Service Level 1 rating can be applied to more than confirmed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.7
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• pp.3794-3820
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• 2019

In recent years, a cloud environment with the ability to detect illegal behaviours along with a secured data storage capability is much needed. This study presents a cloud storage framework, wherein a 128-bit encryption key has been generated by combining deoxyribonucleic acid (DNA) cryptography and the Hill Cipher algorithm to make the framework unbreakable and ensure a better and secured distributed cloud storage environment. Moreover, the study proposes a DNA-based encryption technique, followed by a 256-bit secure socket layer (SSL) to secure data storage. The 256-bit SSL provides secured connections during data transmission. The data herein are classified based on different qualitative security parameters obtained using a specialized fuzzy-based classification technique. The model also has an additional advantage of being able to decide on selecting suitable storage servers from an existing pool of storage servers. A fuzzy-based technique for order of preference by similarity to ideal solution (TOPSIS) multi-criteria decision-making (MCDM) model has been employed for this, which can decide on the set of suitable storage servers on which the data must be stored and results in a reduction in execution time by keeping up the level of security to an improved grade.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11a
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• pp.65-68
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• 2003

컴퓨팅 환경이 유리쿼터스 환경으로 변해가면서 다양한 컨텐츠와 다양한 디바이스들이 등장하게 되었고, 디지털 컨텐츠를 보호하기 위해 DRM(Digital Rights Management) 기술이 적용된 서비스가 제공되고 있다. 그러나 현재 DRM 기술의 디지털 컨텐츠 보안 정책은 일정한 키 길이에 동일한 암호 알고리즘을 사용함으로써 비효율적이고, 사용자의 다양한 요구를 만족시키지 못하고 있다. 본 논문에서는 디지털 컨텐츠에 보안 정책을 효율적으로 적용하고 디바이스의 성능과 디지털 컨텐츠의 가치에 따라 의사 결정 방법인 MAUT(Multi-Attribute Utility Theory) 알고리즘을 이용하여 최적의 보안 등급을 동적으로 결정하는 컨텐츠 암호화 모듈을 설계하고 구현한다.

• Journal of the Korean Society of Safety
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• v.11 no.2
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• pp.150-159
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• 1996

In this paper, an A-team(Asynchronous Team ) based approach for Reactive power and volage control considering static security assessment in a power system with infrastructural deficiencies is proposed. Reactive power and voltage control problem is the one of optimally establishing voltage level given several constraints such as reactive generation, voltage magnitude, line flow, and other switchable reactive power sources. It can be formulated as a mixed-integer linear programming(MILP) problem without deteriorating of solution accuracy to a certain extent. The security assessment is to estimate the relative robustness of the system in Its present state through the evaluation of data provided by security monitoring. Deterministic approach based on AC load flow calculations is adopted to assess the system security, especially voltage security. A security metric, as a standard of measurement for power system security, producting a set of discrete values rather than binary values, is employed. In order to analyze the above two problems, reactive power/voltage control problem and static security assessment problem, in an integrated fashion for real-time operations, a new organizational structure, called an A-team, is adopted. An A-team is an organization for agents which ale all autonomeus, work in parallel and communicate asynchronously, which is well-suited to the development of computer-based, multi-agent systems for operations. This A-team based approach, although it is still in the beginning stage, also has potential for handling other difficult power system problems.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.6 s.336
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• pp.31-38
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• 2005

In this paper, we proposed an optical security system based on a gray-image exclusive-OR encryption using multi-phase separation and phase-wrapping method. For encryption, a gray image is sliced into binary images, which have the same pixel value, and these images are encrypted by modified XOR rules with binary random images. The XORed images and the binary images respectively combined and converted into full phase images, called an encrypted image and a key image. For decryption, when the encrypted image and key image are used as inputs on optical elements, Practically due to limited controllability of phase range in optical elements, the original gray image cannot be efficiently reconstructed by these optical elements. Therefore, by decreasing the phase ranges of the encrypted image and key image using a phase-wrapping method and separating these images into low-level phase images using multi-phase separation, the gray image can be reconstructed by optical elements which have limited control range. The decrytion process is simply implemented by interfering a multiplication result of encrypted image and key image with reference light. The validity of proposed scheme is verified and the effects, which are caused by phase limitation in decryption process, is analyzed by using computer simulations.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.6
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• pp.493-497
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• 2016

Infrared (IR) imaging is capable of detecting targets that are not visible at night, thus it has been widely used for the security and defense system. However, the quality of the IR image is often degraded by low resolution and noise corruption. This paper addresses target segmentation with the IR image. Multiple regions of interest (ROI) are extracted by the multi-level segmentation and targets are segmented from the individual ROI. Each level of the multi-level segmentation is composed of a k-means clustering algorithm an expectation-maximization (EM) algorithm, and a decision process. The k-means clustering algorithm initializes the parameters of the Gaussian mixture model (GMM) and the EM algorithm iteratively estimates those parameters. Each pixel is assigned to one of clusters during the decision. This paper proposes the selection and the merging of the extracted ROIs. ROI regions are selectively merged in order to include the overlapped ROI windows. In the experiments, the proposed method is tested on an IR image capturing two pedestrians at night. The performance is compared with conventional methods showing that the proposed method outperforms others.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.07a
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• pp.93-96
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• 2003

정보통신사회에서 전자서명은 컴퓨터 및 통신망의 확대로 전자거래, 전자결재 등에 활용되어 점점 더 그 중요성이 확대되고 있다. 대리 서명 방식은 전자서명 방식의 한 응용분야로써 1996년 Mambo［1,2］에 의하여 최초로 제안이 되었고, Araki［4］에 의하여 다단계 대리 서명 방식으로 확장되었다. 그러나 제안된 다단계 대리 서명 방식의 연구에서는 다단계로 확장 시 원 서명자를 보호하는 문제와 부인 공격에 대하여 취약하다는 문제가 있다. 따라서 본 연구에서는 PKI기반의 위임 인증서 사용으로 서명 검증자의 서명 생성여부를 원 서명자가 추후 확인 가능하도록 하는 프로토콜을 이용하여 부인봉쇄 및 원 서명자의 보호가 이루어지는 효율적이고 안정적인 다단계 대리 서명 방식을 제안하고자 한다.

• Convergence Security Journal
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• v.5 no.1
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• pp.53-62
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• 2005

Virus protection infrastructure managementis network infrastructure management, traffic route management, virus protection zone expansion, and virus protection management for gateway area. This research paper provides a diagnosis of characteristics and weaknesses of the structure of existing virus protection infrastructure, and recommends an improved multi-level virus protection infrastructure as a measure for correcting these weaknesses. Improved virus protection infrastructure filters unnecessary mail at the gateway stage to reduce the load on server. As a result, numberof transmission accumulation decreases due to the reduction in the CPU load on the Virus wall and increase in virus treatment rate.