• Title/Summary/Keyword: Key block

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A Study on Implementation of BlockChain Voting System using Hyperledger Fabric (Hyperledger Fabric을 활용한 블록체인 투표시스템 구현에 관한 연구)

  • Hwang, Won-Yong;Kim, Hyo-Kwan
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.13 no.4
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    • pp.298-305
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    • 2020
  • This paper deals with the implementation of electronic voting system using permissioned block chain technology. Cases studies have recently been under way in many industrial areas to review the application of the blockchain based electronic voting system. The existing electronic voting system was easily exposed by hacking because of its centralized characteristics, making it difficult to ensure the reliability and transparency of the voting system itself. In this study, we proposed key considerations and concepts to ensure the reliability and transparency of voters and voting stakeholder by utilizing a hyperledger fabric which is nowadays widely used as a permissioned blockchain.

Design of Tag in-Tag out for ATP/ATO in the Light Rail and Monorail (경전철/모노레일의 ATP/ATO를 위한 Tag in-Tag out 설계)

  • Ryu, Deung-Ryeol;Lee, Key-Seo;Oh, Sang-Min
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1264-1269
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    • 2008
  • We designed a track circuit of Tag in-tag out type that can be used for light rails and monorails. This method is called RFID-Tag and it literally uses RFID-Tag and replaces a fixed track circuit and implements a moving block. The distance between RFID-Tags is set to the length of a train and thus a train is always in contact with one of the tags. A train runs in RFID-Tag in -RFID-Tag out type at all times and the distance between trains can be precisely controlled through the application of a moving block combined with the basic principle of a fixed block, which enables the continuous speed control and enhances the satisfaction of passengers. When constructing a track circuit using RFID-Tag the Tag in-tag out brings us the cost reduction and is more economical than the existing fixed track circuit in that sense and easy for installation and maintenance. The wireless communication between onboard and wayside makes the continuous control possible and can improve the control capacity of ATP/ATO by the implementation of a moving block on top of a fixed one.

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An Upper Bound of the Longest Impossible Differentials of Several Block Ciphers

  • Han, Guoyong;Zhang, Wenying;Zhao, Hongluan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.1
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    • pp.435-451
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    • 2019
  • Impossible differential cryptanalysis is an essential cryptanalytic technique and its key point is whether there is an impossible differential path. The main factor of influencing impossible differential cryptanalysis is the length of the rounds of the impossible differential trail because the attack will be more close to the real encryption algorithm with the number becoming longer. We provide the upper bound of the longest impossible differential trails of several important block ciphers. We first analyse the national standard of the Russian Federation in 2015, Kuznyechik, which utilizes the 16-byte LFSR to achieve the linear transformation. We conclude that there is no any 3-round impossible differential trail of the Kuznyechik without the consideration of the specific S-boxes. Then we ascertain the longest impossible differential paths of several other important block ciphers by using the matrix method which can be extended to many other block ciphers. As a result, we show that, unless considering the details of the S-boxes, there is no any more than or equal to 5-round, 7-round and 9-round impossible differential paths for KLEIN, Midori64 and MIBS respectively.

A study on the seismic performance of reinforced concrete frames with dry stack masonry wall using concrete block

  • Joong-Won Lee;Kwang-Ho Choi
    • Earthquakes and Structures
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    • v.24 no.3
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    • pp.205-215
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    • 2023
  • Currently, many studies are underway at home and abroad on the seismic performance evaluation and dry construction method of the masonry structure. In this study, a dry stack masonry wall system without mortar using concrete blocks is proposed, and investigate the seismic performance of dry filling wall frames through experimental studies. First, two types of standard blocks and key blocks were designed to assemble dry walls of concrete blocks. And then, three types of experiments were manufactured, including pure frame, 1/2 height filling wall frame, and full height filling wall frame, and cyclic load experiments in horizontal direction were performed to analyze crack patterns, load displacement history, rebar deformation yield, effective stiffness change, displacement ductility, and energy dissipation capacity. According to the experimental results, the full height filling wall frame had the largest horizontal resistance against the earthquake load and showed a high energy dissipation capacity. However, the 1/2 height filling wall frame requires attention because the filling wall constrains the effective span of the column, limiting the horizontal displacement of the frame. In addition, the concrete block was firmly assembled in the vertical direction of the wall as the horizontal movement between the concrete blocks was allowed within installation margin, and there was no dropping of the assembled concrete block.

Knockout of Myostatin by Zinc-finger Nuclease in Sheep Fibroblasts and Embryos

  • Zhang, Xuemei;Wang, Liqin;Wu, Yangsheng;Li, Wenrong;An, Jing;Zhang, Fuchun;Liu, Mingjun
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.10
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    • pp.1500-1507
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    • 2016
  • Myostatin (MSTN) can negatively regulate the growth and development of skeletal muscle, and natural mutations can cause "double-muscling" trait in animals. In order to block the inhibiting effect of MSTN on muscle growth, we transferred zinc-finger nucleases (ZFN) which targeted sheep MSTN gene into cultured fibroblasts. Gene targeted colonies were isolated from transfected fibroblasts by serial dilution culture and screened by sequencing. Two colonies were identified with mono-allele mutation and one colony with bi-allelic deletion. Further, we introduced the MSTN-ZFN mRNA into sheep embryos by microinjection. Thirteen of thirty-seven parthenogenetic embryos were targeted by ZFN, with the efficiency of 35%. Our work established the technical foundation for generation of MSTN gene editing sheep by somatic cloning and microinjection ZFN into embryos.

Development of Tapered Rolling Type Strip Pressure Key for the Prevention of Scratch (스크래치 방지를 위한 테이퍼 롤링형 판재 누름키의 개발)

  • Kim, Tae-Wan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.12
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    • pp.4715-4720
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    • 2010
  • In this study, we developed new tapered rolling type strip pressure key for the prevention of scratch in sheet metal forming line. The developed pressure key is equipped with two tapered rollers inside a conventional block pressure key. Through the scratch test, for the case of transversal movement the tapered rolling type pressure key reduces both friction and depth of scratch by the effect of tapered shape which decreases the pressure spike on edge, and for longitudinal movement the scratch on the sheet metal surface is certainly removed by the rolling contact.

Stereoscopic Conversion based on Key Frames (키 프레임 기반 스테레오스코픽 변환 방법)

  • 김만배;박상훈
    • Journal of Broadcast Engineering
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    • v.7 no.3
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    • pp.219-228
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    • 2002
  • In this paper, we propose a new method of converting 2D video into 3D stereoscopic video, called stereoscopic conversion. In general, stereoscopic images are produced using the motion informations. However unreliable motion informations obtained especially from block-based motion estimation cause the wrong generation of stereoscopic images. To solve for this problem, we propose a stereoscopic conversion method based upon the utilization of key frame that has the better accuracy of estimated motion informations. As well, as generation scheme of stereoscopic images associated with the motion type of each key frame is proposed. For the performance evaluation of our proposed method, we apply it to five test images and measure the accuracy of key frame-based stereoscopic conversion. Experimental results show that our proposed method has the accuracy more than about 90 percent in terms of the detection ratio of key frames.

A study for the performance evaluation of concrete block assembly wall without using mortar (무모르타르로 건식조립된 콘크리트블록 벽체의 성능평가 연구)

  • Lee, Joong-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.203-210
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    • 2019
  • A recent earthquake on the Korean Peninsula caused much damage to masonry buildings, and research on performance evaluation has been underway. A masonry building is generally constructed using wet construction and is affected by temperature, which reduces the efficiency of the construction. In this study, we propose a dry construction technique for assembling concrete blocks without using mortar and evaluated its performance through experimental and analytical research. To evaluate the performance, experiments were carried out for the prismatic compressive strength, direct terminal strength, and diagonal tensile strength of the dry construction wall. The adequacy of the cross section shape was also reviewed through FEM analysis. The results show that the compressive strength and diagonal tensile strength could exert a certain intensity or higher. Furthermore, the H-type module of a key block acted as a shear key for the entire concrete block, which resulted in excellent shear strength performance. In addition, the shape and thickness of the main block have a major effect on the strength performance of each block. Therefore, an optimal shape and the proposed dry construction method could be applied to replace the wet method by studying the construction or seismic performance of the proposed method.

A Study on Image Integrity Verification Based on RSA and Hash Function (RSA와 해시 함수 기반 이미지 무결성 검증에 관한 연구)

  • Woo, Chan-Il;Goo, Eun-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.11
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    • pp.878-883
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    • 2020
  • Cryptographic algorithms are used to prevent the illegal manipulation of data. They are divided into public-key cryptosystems and symmetric-key cryptosystems. Public-key cryptosystems require considerable time for encryption and decryption compared to symmetric-key cryptosystem. On the other hand, key management, and delivery are easier for public-key cryptosystems than symmetric-key cryptosystems because different keys are used for encryption and decryption. Furthermore, hash functions are being used very effectively to verify the integrity of the digital content, as they always generate output with a fixed size using the data of various sizes as input. This paper proposes a method using RSA public-key cryptography and a hash function to determine if a digital image is deformed or not and to detect the manipulated location. In the proposed method, the entire image is divided into several blocks, 64×64 in size. The watermark is then allocated to each block to verify the deformation of the data. When deformation occurs, the manipulated pixel will be divided into smaller 4×4 sub-blocks, and each block will have a watermark to detect the location. The safety of the proposed method depends on the security of the cryptographic algorithm and the hash function.

A Hardware Design of Ultra-Lightweight Block Cipher Algorithm PRESENT for IoT Applications (IoT 응용을 위한 초경량 블록 암호 알고리듬 PRESENT의 하드웨어 설계)

  • Cho, Wook-Lae;Kim, Ki-Bbeum;Shin, Kyung-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.7
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    • pp.1296-1302
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    • 2016
  • A hardware implementation of ultra-lightweight block cipher algorithm PRESENT that was specified as a block cipher standard for lightweight cryptography ISO/IEC 29192-2 is described in this paper. Two types of crypto-core that support master key size of 80-bit are designed, one is for encryption-only function, and the other is for encryption and decryption functions. The designed PR80 crypto-cores implement the basic cipher mode of operation ECB (electronic code book), and it can process consecutive blocks of plaintext/ciphertext without reloading master key. The PR80 crypto-cores were designed in soft IP with Verilog HDL, and they were verified using Virtex5 FPGA device. The synthesis results using $0.18{\mu}m$ CMOS cell library show that the encryption-only core has 2,990 GE and the encryption/decryption core has 3,687 GE, so they are very suitable for IoT security applications requiring small gate count. The estimated maximum clock frequency is 500 MHz for the encryption-only core and 444 MHz for the encryption/decryption core.