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Design of a IPsec's Message Authentication Module HMAC (HMAC를 이용한 IPsec의 Message Authentication Module 설계)

  • Kim, Yong-Hoon;Ha, Jin-Suk;Lee, Kwang-Youb
    • Annual Conference of KIPS
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    • 2002.04b
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    • pp.813-816
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    • 2002
  • 현재 인터넷은 IPv4(Internetworking Protocol, version 4)를 사용하고 있다. 하지만 데이터 통신은 1970년대에 IPv4가 나온 이래에 발전을 거듭하여 왔다. IPv4는 빠르게 발전하는 인터넷에의 요구를 수용하기 위해 IPv6가 제안되었고 현재 표준이 되었다. IPv6에서는 암호화와 인증옵션들은 패킷의 신뢰성과 무결성을 등을 제공한다. 인터넷에서의 정보보호는 인터넷을 구성하는 여러 계층에서 이루어 질 수 있지만, IPsec에서는 AH(Authentication Header)프로토콜과 IPsec ESP(Encapsulating Security Payload)프로토콜 두 가지의 암호 프로토콜이 사용되지만 AH에서는 HMAC를 이용한 HMAC-MD5나 HMAC-SHA-1 중 하나를 반드시 기본 인증 알고리즘으로 지원하여야 한다. 본 논문에서는 MD5를 이용한 HMAC-MD5를 기준으로 설계하였으며, Iterative Architecture과 Full loop unrolling Architecture의 두 가지 구조를 설계하였다.

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Efficient OTP(One Time Password) Generation using AES-based MAC

  • Park, Soon-Dong;Na, Joong-Chae;Kim, Young-Hwan;Kim, Dong-Kyue
    • Journal of Korea Multimedia Society
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    • v.11 no.6
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    • pp.845-851
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    • 2008
  • The ID/password method is the most classical method among authentication techniques on the internet, and is performed more easily and successfully than other methods. However, it is a vulnerable method against attacks such as eavesdropping or replay attack. To overcome this problem, OTP technique is used. The most popular OTP is HOTP algorithm, which is based on one-way hash function SHA-1. As recent researches show the weakness of the hash function, we need a new algorithm to replace HOTP. In this paper we propose a new OTP algorithm using the MAC(Message Authentication Code) based on AES. We also show that the new OTP outperforms HOTP experimentally.

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A new hash function based on MDx-family hash functions (MDx-계열 해쉬 함수에 기반한 새로운 해쉬 함수)

  • 신상욱
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.7 no.4
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    • pp.59-71
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    • 1997
  • 암호적으로 안전한 해쉬 함수는 디지털 서명, 메세지 인증, 키 유도와 같은 분야에서 중요한 암호도구이다. 현재까지 제안된 소프트웨어로 고속 수행이 가능한 해쉬 함수들의 대부분은 Rivest가 제안한 MD4의 설계 원리에 기반을 두고 있다. 이들 DM계열 해쉬 함수 중에서 현재 안전하다고 알려진 전용 해쉬 함수는 SHA-1, RIPEMD-160, HAVAL등이다.본 논문에서는 디들 세가지 해쉬 함수들의 장점에 기반하여 이들 함수들이 가지는 안전성을 최대한 유지하면서 보다 효율적인 새로운 해쉬 함수를 제안한다. 제안된 해쉬 함수는 임의 길이 메시지를 512비트 단위로 처리하여 160비트의 출력을 가진다. 제안된 해쉬 함수는 입력 데이터에 의존한 순환이동(data-dependent rotation)의 특징을 가짐으로써 기존에 알려진 공격에 강인함을 보장하며 두 새의 충돌 메시지 발견을 위해서는 생일공격에 의해 2연산이 요구되어진다고 추측된다. 제안된 해쉬 함수의 성능은 수행 속도면에서 RIPEMD-160보다 약 30%보다는 약 7%효율적이다.

A Study on Enhancing Hash Function Security against Collision Search Attack (충돌쌍 탐색 공격에 대한 해쉬 함수 안전성 강화에 관한 연구)

  • Jeong, Eun-Jin;Han, Jeong-Hoon;Kim, Seung-Joo;Won, Dong-Ho
    • Annual Conference of KIPS
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    • 2008.05a
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    • pp.1120-1123
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    • 2008
  • 단방향 암호화 함수인 해쉬 함수는 2005년 Wang의 새로운 공격법이 발표되면서 안전성에 대한 문제점이 조금씩 드러나기 시작하고 있다. Wang의 새로운 차분 공격법은 현재 가장 널리 사용하고 있는 해쉬 알고리즘인 SHA-1을 이론적으로 269의 계산으로 충돌을 찾을 수 있다고 하였다. 본 논문에서는 차분 공격이 이루어지는 방법과 Wang의 차분 공격이 지니는 두 가지 특성에 대해서 연구하였고, MDx계열의 해쉬 함수의 안전성에 대한 기존의 제시된 해결책과 다른, 한 블록의 모든 워드 값을 변형 처리한 방식을 제안한다.

Molecular Cloning, Identification and Characteristics of a Novel Isoform of Carbamyl Phosphate Synthetase I in Human Testis

  • Huo, Ran;Zhu, Hui;Lu, Li;Ying, Lanlan;Xu, Min;Xu, Zhiyang;Li, Jianmin;Zhou, Zuomin;Sha, Jiahao
    • BMB Reports
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    • v.38 no.1
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    • pp.28-33
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    • 2005
  • A gene coding a novel isoform of carbamyl phosphate synthetase I (CPS1) was cloned from a human testicular library. As shown by cDNA microarray hybridization, this gene was expressed at a higher level in human adult testes than in fetal testes. The full length of its cDNA was 3831 bp, with a 3149 bp open reading frame, encoding a 1050-amino-acid protein. The cDNA sequence was deposited in the GenBank (AY317138). Sequence analysis showed that it was homologous to the human CPS1 gene. The putative protein contained functional domains composing the intact large subunit of carbamoyl phosphate synthetase, thus indicated it has the capability of arginine biosynthesis. A multiple tissue expression profile showed high expression of this gene in human testis, suggesting the novel alternative splicing form of CPS1 may be correlated with human spermatogenesis.

A 12b 200KHz 0.52mA 0.47mm2 Algorithmic A/D Converter for MEMS Applications (마이크로 전자 기계 시스템 응용을 위한 12비트 200KHz 0.52mA 0.47mm2 알고리즈믹 A/D 변환기)

  • Kim, Young-Ju;Chae, Hee-Sung;Koo, Yong-Seo;Lim, Shin-Il;Lee, Seung-Hoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.11 s.353
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    • pp.48-57
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    • 2006
  • This work describes a 12b 200KHz 0.52mA 0.47mm2 algorithmic ADC for sensor applications such as motor controls, 3-phase power controls, and CMOS image sensors simultaneously requiring ultra-low power and small size. The proposed ADC is based on the conventional algorithmic architecture with recycling techniques to optimize sampling rate, resolution, chip area, and power consumption. The input SHA with eight input channels for high integration employs a folded-cascode architecture to achieve a required DC gain and a sufficient phase margin. A signal insensitive 3-D fully symmetrical layout with critical signal lines shielded reduces the capacitor and device mismatch of the MDAC. The improved switched bias power-reduction techniques reduce the power consumption of analog amplifiers. Current and voltage references are integrated on the chip with optional off-chip voltage references for low glitch noise. The employed down-sampling clock signal selects the sampling rate of 200KS/s or 10KS/s with a reduced power depending on applications. The prototype ADC in a 0.18um n-well 1P6M CMOS technology demonstrates the measured DNL and INL within 0.76LSB and 2.47LSB. The ADC shows a maximum SNDR and SFDR of 55dB and 70dB at all sampling frequencies up to 200KS/s, respectively. The active die area is 0.47mm2 and the chip consumes 0.94mW at 200KS/s and 0.63mW at 10KS/s at a 1.8V supply.

Effects of acute and chronic heat stress on the rumen microbiome in dairy goats

  • Min Li;Lian-Bin Xu;Chen Zhang;Pei-Hua Zhang;Sha Tao;Hong-Yun Liu
    • Animal Bioscience
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    • v.37 no.12
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    • pp.2081-2090
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    • 2024
  • Objective: The objective of this study was to reveal the influence of acute and chronic heat stress (HS) on the abundance and function of rumen microbiome and host metabolism. Methods: Forty mid-lactation goats were randomly divided into two artificial environments: control group and heat-stressed group. This study was recorded from two periods, 1 day and 28 days. The first day was defined as control 1 (CT1) and HS 1 (acute HS), and the last day was defined as CT28 and HS28 (chronic HS). On the first and last day, 6 dairy goats in each group were randomly selected to collect rumen liquid after the morning feeding through oral stomach tubes. The barn temperature and humidity were recorded every day. Results: Disruption of the rumen microbiome was observed under chronic HS, represented by an increase in the abundance of Prevotella and Bacteroidales (p<0.05), and upregulation of carbohydrate transport and metabolism functions (p<0.05). Additionally, the abundance of Succinimonas and Ruminobacter in chronic HS is lower than in acute HS (p<0.05), and the functions of intracellular trafficking, secretion and vesicular transport, and the cytoskeleton were downregulated (p<0.05). Conclusion: The HS affected the interaction between the microbiota and host, thereby regulated milk production in dairy goats. These findings increased understanding of the crosstalk between hosts and bacteria.

A Security SoC embedded with ECDSA Hardware Accelerator (ECDSA 하드웨어 가속기가 내장된 보안 SoC)

  • Jeong, Young-Su;Kim, Min-Ju;Shin, Kyung-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.7
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    • pp.1071-1077
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    • 2022
  • A security SoC that can be used to implement elliptic curve cryptography (ECC) based public-key infrastructures was designed. The security SoC has an architecture in which a hardware accelerator for the elliptic curve digital signature algorithm (ECDSA) is interfaced with the Cortex-A53 CPU using the AXI4-Lite bus. The ECDSA hardware accelerator, which consists of a high-performance ECC processor, a SHA3 hash core, a true random number generator (TRNG), a modular multiplier, BRAM, and control FSM, was designed to perform the high-performance computation of ECDSA signature generation and signature verification with minimal CPU control. The security SoC was implemented in the Zynq UltraScale+ MPSoC device to perform hardware-software co-verification, and it was evaluated that the ECDSA signature generation or signature verification can be achieved about 1,000 times per second at a clock frequency of 150 MHz. The ECDSA hardware accelerator was implemented using hardware resources of 74,630 LUTs, 23,356 flip-flops, 32kb BRAM, and 36 DSP blocks.

Identification of Novel Clubroot Resistance Loci in Brassic rapa

  • Pang, Wenxing;Chen, Jingjing;Yu, Sha;Shen, Xiangqun;Zhang, Chunyu;Piao, Zhongyun
    • 한국균학회소식:학술대회논문집
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    • 2015.05a
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    • pp.42-42
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    • 2015
  • Plasmodiophora brassicae, the causal agent of clubroot disease, does the most serious damage to the Brassica crops. The limited control approaches make that the identification of clubroot resistance (CR) is more important for developing CR cultivars of the Brassica crops. So far, 8 CR loci were mapped. However, the variation of P. brassicae leads to the rapid erosion of its resistance. To identify novel CR genes, we employed three mapping population, derived from crosses between Chinese cabbage and turnip inbred lines (591×ECD04 and BJN31×Siloga) or between Chinese cabbage inbred lines (BJN31×85III), to perform QTL analysis. Totally, 8 CR loci were indentified and showed race-specific resistance. Physical mapping of these 8 loci suggested that 4 were located previously mapped position, indicating they might be the same allele or different alleles of the same genes. Other 4 loci were found to be novel. Further, CR near isogenic line carrying each CR locus was developed based on the marker assisted selection. Verification of these CR loci was underway. Identification of these novel CR genes would facilitate to breed broad-spectrum and durable CR cultivars of B. rapa by pyramiding strategies.

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A Rail-to-Rail Input 12b 2 MS/s 0.18 μm CMOS Cyclic ADC for Touch Screen Applications

  • Choi, Hee-Cheol;Ahn, Gil-Cho;Choi, Joong-Ho;Lee, Seung-Hoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.9 no.3
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    • pp.160-165
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    • 2009
  • A 12b 2 MS/s cyclic ADC processing 3.3 Vpp single-ended rail-to-rail input signals is presented. The proposed ADC demonstrates an offset voltage less than 1 mV without well-known calibration and trimming techniques although power supplies are directly employed as voltage references. The SHA-free input sampling scheme and the two-stage switched op-amp discussed in this work reduce power dissipation, while the comparators based on capacitor-divided voltage references show a matched full-scale performance between two flash sub ADCs. The prototype ADC in a 0.18μm 1P6M CMOS demonstrates the effective number of bits of 11.48 for a 100 kHz full-scale input at 2 MS/s. The ADC with an active die area of 0.12mm2 consumes 3.6 m W at 2 MS/s and 3.3 V (analog)/1.8 V (digital).