• Title/Summary/Keyword: key block

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A Study on the Characteristics of Behavior of Block-type Reinforced Earth Retaining Wall Considering Failure Surface (파괴면을 고려한 블록식 보강토 옹벽의 거동 특성 연구)

  • Yoon, Won-Sub;Park, Jun-Kyu;Chae, Young-Su
    • Journal of the Korean Geosynthetics Society
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    • v.15 no.3
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    • pp.13-26
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    • 2016
  • In this study, more economical than conventional reinforced soil retaining walls, we compared the behavior characteristic about the safety block type numerically for reinforced retaining wall. In this study, reinforced soil retaining wall, first, was integrated a wall putting shear key on the blocks. Second, construction reinforcement focused on the theoretical failure surface was satisfied with the stability of a retaining wall reinforced by a shear plane. when analyzing, element of using reinforcement was carried out a numerical analysis for the cable element and the strip element, and they were analyzed under the conditions according to the stiffener length, distance, with or without shear key. Analysis for the integration of the front wall was reinforced soil retaining walls by installing a larger displacement shear key confinement effect, if reinforced construction and reinforcement with 1 interval and 2 interval, the failure surface was bigger displacement constraints. Generating a deformation amount was smaller than the generation amount of deformation accrued during construction of AASHTO so that it was stable.

Optimized Implementation of PIPO Lightweight Block Cipher on 32-bit RISC-V Processor (32-bit RISC-V상에서의 PIPO 경량 블록암호 최적화 구현)

  • Eum, Si Woo;Jang, Kyung Bae;Song, Gyeong Ju;Lee, Min Woo;Seo, Hwa Jeong
    • KIPS Transactions on Computer and Communication Systems
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    • v.11 no.6
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    • pp.167-174
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    • 2022
  • PIPO lightweight block ciphers were announced in ICISC'20. In this paper, a single-block optimization implementation and parallel optimization implementation of PIPO lightweight block cipher ECB, CBC, and CTR operation modes are performed on a 32-bit RISC-V processor. A single block implementation proposes an efficient 8-bit unit of Rlayer function implementation on a 32-bit register. In a parallel implementation, internal alignment of registers for parallel implementation is performed, and a method for four different blocks to perform Rlayer function operations on one register is described. In addition, since it is difficult to apply the parallel implementation technique to the encryption process in the parallel implementation of the CBC operation mode, it is proposed to apply the parallel implementation technique in the decryption process. In parallel implementation of the CTR operation mode, an extended initialization vector is used to propose a register internal alignment omission technique. This paper shows that the parallel implementation technique is applicable to several block cipher operation modes. As a result, it is confirmed that the performance improvement is 1.7 times in a single-block implementation and 1.89 times in a parallel implementation compared to the performance of the existing research implementation that includes the key schedule process in the ECB operation mode.

Experimental study on vertically upward steam-water two-phase flow patterns in narrow rectangular channel

  • Zhou, Jiancheng;Ye, Tianzhou;Zhang, Dalin;Song, Gongle;Sun, Rulei;Deng, Jian;Tian, Wenxi;Su, G.H.;Qiu, Suizheng
    • Nuclear Engineering and Technology
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    • v.53 no.1
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    • pp.61-68
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    • 2021
  • Experiments of vertically upward steam-water two-phase flow have been carried out in single-side heated narrow rectangular channel with a gap of 3 mm. Flow patterns were identified and classified through visualization directly. Slug flow was only observed at 0.2 MPa but replaced by block-bubble flow at 1.0 MPa. Flow pattern maps at the pressure of 0.2 MPa and 1.0 MPa were plotted and the difference was analyzed. The experimental data has been compared with other flow pattern maps and transition criteria. The results show reasonable agreement with Hosler's, while a wide discrepancy is observed when compared with air-water two-phase experimental data. Current criteria developed based on air-water experiments poorly predict bubble-slug flow transition due to the different formation and growth of bubbles. This work is significant for researches on heat transfer, bubble dynamics and flow instability.

An Efficient Anonymous Authentication and Vehicle Tracing Protocol for Secure Vehicular Communications

  • Park, Young-Shin;Jung, Chae-Duk;Park, Young-Ho;Rhee, Kyung-Hyune
    • Journal of Korea Multimedia Society
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    • v.13 no.6
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    • pp.865-874
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    • 2010
  • Recently, Hao et al. proposed a privacy preservation protocol based on group signature scheme for secure vehicular communications to overcome a well-recognized problems of secure VANETs based on PKI. However, although efficient group signature schemes have been proposed in cryptographic literatures, group signature itself is still a rather much time consuming operation. In this paper, we propose a more efficient privacy preservation protocol than that of Hao et al. In order to design a more efficient anonymous authentication protocol, we consider a key-insulated signature scheme as our cryptographic building block. We demonstrate experimental results to confirm that the proposed protocol is more efficient than the previous scheme.

A Study of Anime's Success Factors in USA and Its Suggestions

  • Won, Kang-Sik
    • International Journal of Contents
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    • v.3 no.1
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    • pp.29-33
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    • 2007
  • Anime is very popular in Japan, it has also gained a following in America and is beginning to hit the mainstream. Anime is gaining popularity in the United States as it is shown more on television, most noticeably on the Sci-Fi Channel with shows such as Saturday Anime and during Anime Week and on Cartoon Network with shows such as Sailor Moon and Dragon Ball Z being shown every weekday during the Toonami block. In this paper, I present the key factors behind the success of anime in USA. To find out the factors, I research literature and simple survey. The differences of anime from us animation make anime popular. Anime-related goods such as video games, trading cards, and characters' jewelry aid the anime growing popularity. A booming trend in admiration for Japan is one of the key factors behind anime's success. In spite of disputing about Japanese animation, anime is starting to have some influence on US animation and also young American. Anime's success factors in USA could suggest that Korean Manhwa and Korean animation have to prepare strategies for rising popularity in oversea.

Security Analysis of AES-CMAC Applicable to Various Environments (다양한 환경에 적용 가능한 AES-CMAC에 대한 안전성 분석)

  • Jeong, Ki-Tae
    • Journal of Advanced Navigation Technology
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    • v.16 no.2
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    • pp.211-218
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    • 2012
  • In this paper, we propose a fault injection attack on AES-CMAC, which is defined by IETF. The fault assumption used in this attack is based on that introduced at FDTC'05. This attack can recover the 128-bit secret key of AES-CMAC by using only small number of fault injections. This result is the first known key recovery attack result on AES-CMAC.

Design and Analysis of the GOST Encryption Algorithm (GOST 암호화 알고리즘의 구현 및 분석)

  • 류승석;정연모
    • Journal of the Korea Society for Simulation
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    • v.9 no.2
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    • pp.15-25
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    • 2000
  • Since data security problems are very important in the information age, cryptographic algorithms for encryption and decryption have been studied for a long time. The GOST(Gosudarstvennyi Standard or Government Standard) algorithm as a data encryption algorithm with a 256-bit key is a 64-bit block algorithm developed in the former Soviet Union. In this paper, we describe how to design an encryption chip based on the GOST algorithm. In addition, the GOST algorithm is compared with the DES(Data Encryption Standard) algorithm, which has been used as a conventional data encryption algorithm, in modeling techniques and their performance. The GOST algorithm whose key size is relatively longer than that of the DES algorithm has been expanded to get better performance, modeled in VHDL, and simulated for implementation with an CPLD chip.

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A Study on Lucifer-Type Encryption Algorithm (Lucifer 형태의 암호화 알고리듬에 관한 연구)

  • Gahng, Hae-Dong;Lee, Chang-Soon;Moon, Sang-Jae
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.3
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    • pp.32-39
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    • 1989
  • This paper presents Lucifer-type encryption algorythms with variable length of block size of 32, 64, and 256 bits by varying the key byte access schedule and the unfolded convolution register of Lucifer. The intersymbol dpendence and exhaustive cryptanalysis of the algorithms are examined and compared. We also present the methods which improve the intersymbol dependence such as moving the location of key interruption and autoclave selection of S-box.

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A Study on KSI-based Authentication Management for Efficient Private Block Chain (효율적인 Private Blockchain을 위한 KSI기반의 인증관리에 관한 연구)

  • Ra, Gyeong-Jin;Lee, Im-Yeong
    • Annual Conference of KIPS
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    • 2018.05a
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    • pp.155-156
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    • 2018
  • 블록체인은 DLT 기술로서, P2P 네트워크의 영역별로 유지 관리되는 트랜잭션의 추가 전용 공유 레코드 기술이다. 그 중 Private Blockchain은 허가된 사용자 멤버만으로 구성된 블록체인 환경으로, 소수의 신뢰노드만이 블록 생성 합의에 참여하여 빠른 블록체인을 형성하고 이를 하나의 원장으로 공유한다. 따라서 본 논문에서는 Private Blockchain의 허가된 사용자의 신원확인을 위한 인증구조인 PKI(Public Key Infrastructure)와 AKI(Accountable Key Infrastructure)를 비교 분석하고 KSI(Keyless Signature Infrastructure)기반의 인증관리를 제안한다.

Improvement of Security Cryptography Algorithm in Transport Layer (전달 계층의 보안 암호화 알고리즘 개선)

  • Choi Seung-Kwon;Kim Song-Young;Shin Dong-Hwa;Lee Byong-Rok;Cho Yong-Hwan
    • Proceedings of the Korea Contents Association Conference
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    • 2005.05a
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    • pp.107-111
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    • 2005
  • As Internet grows rapidly and next electronic commerce applications increase, the security is getting more important. Information security to provide secure and reliable information transfer is based on cryptography technique. The proposed ISEED(Improved SEED) algorithm based on block cryptography algorithm which belongs to secret-key algorithm. In terms of efficiency, the round key generation algorithm has been proposed to reduces the time required in encryption and decryption. The algorithm has been implemented as follow. 128-bit key is divided into two 64-bit group to rotate each of them 8-bit on the left side and right side, and then basic arithmetic operation and G function have been applied to 4-word outputs. In the process of converting encryption key which is required in decryption and encryption of key generation algorithm into sub key type, the conversion algorithm is analyzed. As a result, the time consumed to encryption and decryption is reduced by minimizing the number of plain text required differential analysis.

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