• Title/Summary/Keyword: block code

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An Area-efficient Design of SHA-256 Hash Processor for IoT Security (IoT 보안을 위한 SHA-256 해시 프로세서의 면적 효율적인 설계)

  • Lee, Sang-Hyun;Shin, Kyung-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.1
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    • pp.109-116
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    • 2018
  • This paper describes an area-efficient design of SHA-256 hash function that is widely used in various security protocols including digital signature, authentication code, key generation. The SHA-256 hash processor includes a padder block for padding and parsing input message, so that it can operate without software for preprocessing. Round function was designed with a 16-bit data-path that processed 64 round computations in 128 clock cycles, resulting in an optimized area per throughput (APT) performance as well as small area implementation. The SHA-256 hash processor was verified by FPGA implementation using Virtex5 device, and it was estimated that the throughput was 337 Mbps at maximum clock frequency of 116 MHz. The synthesis for ASIC implementation using a $0.18-{\mu}m$ CMOS cell library shows that it has 13,251 gate equivalents (GEs) and it can operate up to 200 MHz clock frequency.

Turbo-coded STC schemes for an integrated satellite-terrestrial system for cooperative diversity (협동 다이버시티 이득을 위한 위성-지상간 통합망에서의 터보 부호화된 시공간 부호)

  • Park, Un-Hee;Kim, Soo-Young;Kim, Hee-Wook;Ahn, Do-Seob
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.1A
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    • pp.62-70
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    • 2010
  • In this paper, we evaluate the performance of various diversity techniques which can contribute to provide efficient multimedia broadcasting services via hybrid/integrated satellite and terrestrial network. Space-time coding (STC) can achieve the diversity gain in a multi-path environment without additional bandwidth requirement. Recent study results reported that satellite systems can achieve high diversity gains by appropriate utilization of STC and/or forward error correction schemes. Based on these previous study results, we present various cooperative diversity techniques by combining STC and rate compatible turbo codes in order to realize the transmit diversity for the mobile satellite system. The satellite and several terrestrial repeaters operate in unison to send the encoded signals, so that receiver may realize diversity gain. The results demonstrated in this paper can be utilized in future system implementation.

A Study on Smart EDR System Security Development (Smart EDR 시스템구축을 위한 보안전략과 발전방안)

  • Yoo, Seung Jae
    • Convergence Security Journal
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    • v.20 no.1
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    • pp.41-47
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    • 2020
  • In the corporate information system environment, detecting and controlling suspicious behaviors occurring at the end point of the actual business application is the most important area to secure the organization's business environment. In order to accurately detect and block threats from inside and outside, it is necessary to be able to monitor all areas of all terminals in the organization and collect relevant information. In other words, in order to maintain a secure business environment of a corporate organization from the constant challenge of malicious code, everything that occurs in a business terminal such as a PC beyond detection and defense-based client security based on known patterns, signatures, policies, and rules that have been universalized in the past. The introduction of an EDR solution to enable identification and monitoring is now an essential element of security. In this study, we will look at the essential functions required for EDR solutions, and also study the design and development plans of smart EDR systems based on active and proactive detection of security threats.

Performance Analysis of Cooperative Communication with Spread Spectrum to Overcome Channel Blockage for On-The-Move Terminal in Next Generation Satellite Communication Systems (차기 군 위성통신체계 환경에서 이동형 위성단말의 채널 blockage 극복을 위한 확산기반 협업통신 기법의 성능 분석)

  • Park, Hyung-Won;Lee, Ho-Sub;Yoon, Won-Sik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.9
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    • pp.757-766
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    • 2014
  • To compensate signal loss due to the channel blockage in satellite communication link, we propose a cooperative communication scheme for OTM(On-The-Move) terminal in next generation satellite communication systems. The proposed scheme configures cooperation subnet with adjacent OTM terminal with the help of ground communication equipment. Shared data is spread by orthogonal spreading code, then the spread sequences are transmitted simultaneously. The receiver combines the power of received signals by EGC(Equal gain combining). The OTM terminal blockage channel is modeled by 2-state Markov chain. We evaluate the bit error rate according to the blockage channel of the channel state for the performance analysis of the proposed scheme. As a result, the proposed scheme shows better BER performance than traditional scheme with the help of subset members. In particular, the proposed scheme shows superior performance as the channel block probability is higher. However, as the number of subset members is increasing, there is a constraint because of the higher multiple access interference.

An Adaptive ROI Mask Generation for ROI coding of JPEG2000 (JPEG200의 관심영역 부호화를 위한 적응적인 관심영역 마스크 생성 방법)

  • Kang, Ki-Jun;Seo, Yeong-Geon
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.5
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    • pp.39-47
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    • 2007
  • In this thesis, a method of generating an adaptable Region-Of-Interest(ROI) Mask for the Region-Of-Interest coding is suggested. In the method, an ROI Mask is generated using the information of the ROI designated by a user. In the existed method of ROI coding, after scanning all the pixels in order and discriminating an ROI, an ROI Mask is generated. But, in our method, after scanning a part of pixels based on the shape pattern of an ROI and discriminating a ROI by one code block unit, an ROI Mask is generated. Moreover, from the method, a pattern number, threshold of a ROI and background threshold parameter are provided. According to the result of its comparing test with the existed methods to show the usability, it is proved that our method is superior in speed to the existed ones.

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UWB System Performance Analysis of STBC-OFDM Using Frequency Diversity (주파수 다이버시티가 적용된 STBC-OFDM의 UWB 시스템 성능 분석)

  • Kim Nam;Choi Jung-Hun;Han Tae-Young
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.4 s.95
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    • pp.351-358
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    • 2005
  • In this paper, STBC(Space Time Block Code) is applied to the UWB system and frequency repeated diversity is used to get the 4-th order space time diversity gain. The performance of UWB STBC-OFDM system is analyzed by computer simulation. As a result of analysis, proposed UWB system can reduce the complexity that is introduced by increaing number of radiator and show the same performance of 4 antennas with that only using 2 radiator. This system at the $10^{-4}$ also shows the enhancement of $7.1\;\cal{dB}$ to the general UWB OFDM and $1.9\;\cal{dB}$ to UWB STBC-OFDM.

Design of Housing Structure for the Suppression of Higher­Order Modes in the Microstrip Circuit Packaging (마이크로스트립 회로 패키징의 고차모드 차폐를 위한 하우징 설계)

  • 전중창
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.8
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    • pp.1621-1628
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    • 2003
  • Packaging structures to block the propagation of higher­order modes in the shielded microstrip lines are designed. Packaging for microwave circuits is necessary, basically, to isolate and protect circuits from outside environments both physically and electrically. The drawback of packaging is the possibility of higher­order mode propagation, similar to waveguide modes, as the operating frequency increases. One of Possible choices for the higher­order mode suppression is to insert diaphragms to the housing structure. The shielding effects of diaphragms are analyzed using an FEM code. Several parameters such as dispersion, mode conversion, and higher­order mode transmission and reflection are analyzed. The effect of higher­order mode suppression is eminent as the depth or width of a diaphragm is increased in the air region of the microstrip line. It is shown that inductive diaphragm structure can lower ${S_21}$ for the second­order mode incidence by 30㏈, comparing with the conventional capacitive diaphragm structure. Packaging structure analyzed in this paper can be applied usefully to the design of the microwave system in a package such as transmit/receive modules.

Performance Improvement of Space-Time OFDM System with Concatenated Codes (연접부호를 적용한 시공간 OFDM 시스템의 성능 개선)

  • 서완우;정연호
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.3
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    • pp.541-546
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    • 2004
  • Space-Time Coding(STC) is a technique that utilizes joint correlation of transmitted signals in both time and space domains. Through this approach, diversity and coding gains can be simultaneously obtained. In this paper, we use SPW simulation tool to implement the IEEE 802.11a system. Based on this system, OFDM system with STC and convolutional coder concatenated is implemented. The system performance is analyzed and compared with the performance of the IEEE 802.11a system. The simulation results show that the performance with concatenated codes at a data rate of 6Mbps shows approximately a 5dB gain over the system with the convolutional code only. At a data rate of 12Mbps, the performance with concatenated codes is further improved by approximately 6dB.

Mutual Authentication Protocol for Safe Data Transmission of Multi-distributed Web Cluster Model (다중 분산 웹 클러스터모델의 안전한 데이터 전송을 위한 상호 인증 프로토콜)

  • Lee, Kee-Jun;Kim, Chang-Won;Jeong, Chae-Yeong
    • The KIPS Transactions:PartC
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    • v.8C no.6
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    • pp.731-740
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    • 2001
  • Multi-distributed web cluster model expanding conventional cluster system is the cluster system which processes large-scaled work demanded from users with parallel computing method by building a number of system nodes on open network into a single imaginary network. Multi-distributed web cluster model on the structured characteristics exposes internal system nodes by an illegal third party and has a potential that normal job performance is impossible by the intentional prevention and attack in cooperative work among system nodes. This paper presents the mutual authentication protocol of system nodes through key division method for the authentication of system nodes concerned in the registration, requirement and cooperation of service code block of system nodes and collecting the results and then designs SNKDC which controls and divides symmetrical keys of the whole system nodes safely and effectively. SNKDC divides symmetrical keys required for performing the work of system nodes and the system nodes transmit encoded packet based on the key provided. Encryption packet given and taken between system nodes is decoded by a third party or can prevent the outflow of information through false message.

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A Design of Mobile Web Server Framework for SOAP Transaction and Performance Enhancement in Web2.0 (웹2.0에서 SOAP 처리와 성능 향상을 위한 모바일 웹 서버 프레임워크의 설계)

  • Kim, Yong-Tae;Jeong, Yoon-Su;Park, Gil-Cheol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.10
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    • pp.1866-1874
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    • 2008
  • Existing web server lowers the whole capacity of system because of the problem on the processing load of server by closing connection increasing code handshake operation, and remarkable decrease of server capacity if it is the state of overload. Also, there occurs disadvantages of increasing connection tine about client's request and response time because handling of client's multi-requests is not smooth because of thread block and it requests a lot of time and resources for revitalization of thread. Therefore, this paper proposes the extended web server which provides the technique for delay handling and improves the overload of server for better system capacity, communication support, and the unification which is the advantage of web service. And it evaluates the existing system(implemented at Tomcat 5.5) and the proposed mobile web server architecture. The extended server architecture provides excellent exchange condition for system capacity and evaluates improved web server architecture which combines multi-thread with thread pool. The proposed web service architecture in this paper got the better result of improved capacity benefit than the evaluation result of original Tomcat 5.5.