• 정보보호학회논문지
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• 제30권5호
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• pp.795-803
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• 2020

본 논문에서는 SP 구조의 F-함수를 가진 4-브랜치 GFN-2 구조에 대한 기지키 구별 공격(Known-Key Distinguishing Attack) 및 부분 충돌 공격(Partial-Collision Attack)을 연구한다. 첫 번째로, 이 구조에 대해 기지키 구별 공격이 15 라운드까지 가능함이 밝혀진다. 두 번째로, 마지막 라운드에 셔플 연산이 있는 경우, 부분 충돌 공격이 14 라운드까지 가능함이 밝혀진다. 마지막으로, 마지막 라운드에 셔플 연산이 없는 경우, 부분 충돌 공격이 15 라운드까지 가능함이 밝혀진다.

• 한국시뮬레이션학회논문지
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• 제25권3호
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• pp.77-83
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• 2016

본 논문에서는 부분 암호화를 위한 키 생성 및 관리 알고리즘의 연구한다. 제안하는 알고리즘에서는 해쉬 트리 구조를 이용하여 적은 양의 해쉬키로부터 다양한 암호화 키를 생성하는 기능을 제공하고 있다. 본 논문에서는 새로운 키 생성 알고리즘을 이용하여 부분 암호화 및 부분 복호화하는 방법을 제시하고 시뮬레이션을 통하여 그 성능을 분석한다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.745-746
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• 2005

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권1호
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• pp.280-295
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• 2015

Block cipher ARIA was first proposed by some South Korean experts in 2003, and later, it was established as a Korean Standard block cipher algorithm by Korean Agency for Technology and Standards. In this paper, we focus on the security evaluation of ARIA block cipher against the recent zero-correlation linear cryptanalysis. In addition, Partial-sum technique and FFT (Fast Fourier Transform) technique are used to speed up the cryptanalysis, respectively. We first introduce some 4-round linear approximations of ARIA with zero-correlation, and then present some key-recovery attacks on 6/7-round ARIA-128/256 with the Partial-sum technique and FFT technique. The key-recovery attack with Partial-sum technique on 6-round ARIA-128 needs $2^{123.6}$ known plaintexts (KPs), $2^{121}$ encryptions and $2^{90.3}$ bytes memory, and the attack with FFT technique requires $2^{124.1}$ KPs, $2^{121.5}$ encryptions and $2^{90.3}$ bytes memory. Moreover, applying Partial-sum technique, we can attack 7-round ARIA-256 with $2^{124.6}$ KPs, $2^{203.5}$ encryptions and $2^{152}$ bytes memory and 7-round ARIA-256 employing FFT technique, requires $2^{124.7}$ KPs, $2^{209.5}$ encryptions and $2^{152}$ bytes memory. Our results are the first zero-correlation linear cryptanalysis results on ARIA.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.135-136
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• 2002

Molybdenum Nitrided (MoNx) films were deposited by DC planar magnetron sputtering. Silicon wafers and real nitrided stainless steel piston rings are employed as substrates. 12 different combinations of nitrogen and argon partial pressure, from 1:7 to 7:1, were applied to deposit MoNx films. X-ray diffraction (XRD) was used to determine the phase structures of films. When nitrogen vs. argon partial pressure is 1:7, the film is mainly $Mo_2N$ phase. With increase of nitrogen partial pressure, MoN phase emerges, but $Mo_2N$ phase still exists. Composition analysis with atomic emission spectrometry (AES) also agreed with this. The films have very high nanohardness (max 2400Hv) and good adhesion to the substrates.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2004년도 추계 종합학술대회 논문집
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• pp.448-452
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• 2004

부분키를 사용한 캐쉬 인식 $B^+$ 트리는 키 압축과 포인터 압축 방법을 동시에 적용한 캐쉬 인식 트리이다. 기존의 캐쉬 인식 트리들은 키 압축과 포인터 압축을 따로 고려하였다. 이에 반해 부분키를 사용한 캐쉬 인식 $B^+$ 트리는 키와 포인터를 동시에 압축하여 캐쉬 활용도를 높였다. 본 논문은 기 발표된 부분키를 사용한 캐쉬 인식 $B^+$ 트리의 벌크로드와 검색 알고리즘을 구현하여 성능 평가를 수행하였다. 그리고 $B^+$-트리와 Simple Prefix $B^+$-트리의 성능비교를 통하여 부분키 캐쉬 인식 $B^+$ 트리의 성능의 우수함을 확인 하였다.

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2008년도 제7회 추계학술대회 및 정기총회
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• pp.578-580
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• 2008

• 한국진공학회지
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• 제12권S1호
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• pp.83-87
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• 2003

Zirconium oxide films have been synthesized by radio-frequency magnetron sputtering deposition on n-Si(001) substrate with metal zirconium target at variant $O_2$ partial pressures. The influences of $O_2$ partial pressures of the morphology, deposition rate, microstructure, and the dielectric constant of $ZrO_2$ have been discussed. The results show that deposition rate of $ZrO_2$ films decreases, the roughness, and the thickness of the native $SiO_2$ interlayer increases with the increase of $O_2$ partial pressure. $ZrO_2$ films synthesized at low $O_2$ partial pressure are amorphous and monoclinic polycrystalline in nanometer scale at low $O_2$ partial pressure. The relative dielectrics of $ZrO_2$ films are in the range of 12 to 25.

• Journal of Power Electronics
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• 제19권5호
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• pp.1248-1258
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• 2019

This paper presents a moth-flame optimization (MFO)-based maximum power point tracking (MPPT) method for photovoltaic (PV) systems. The MFO algorithm is a new optimization method that exhibits satisfactory performance in terms of exploration, exploitation, local optima avoidance, and convergence. Therefore, the MFO algorithm is quite suitable for solving multiple peaks of PV systems under partial shading conditions (PSCs). The proposed MFO-MPPT is compared with four MPPT algorithms, namely the perturb and observe (P&O)-MPPT, incremental conductance (INC)-MPPT, particle swarm optimization (PSO)-MPPT and whale optimization algorithm (WOA)-MPPT. Simulation and experiment results demonstrate that the proposed algorithm can extract the global maximum power point (MPP) with greater tracking speed and accuracy under various conditions.

• Journal of information and communication convergence engineering
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• 제13권1호
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• pp.27-35
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• 2015

Multiprecision multiplication is the most expensive operation in public key-based cryptography. Therefore, many multiplication methods have been studied intensively for several decades. In Workshop on Cryptographic Hardware and Embedded Systems 2011 (CHES2011), a novel multiplication method called 'operand caching' was proposed. This method reduces the number of required load instructions by caching the operands. However, it does not provide full operand caching when changing the row of partial products. To overcome this problem, a novel method, that is, 'consecutive operand caching' was proposed in Workshop on Information Security Applications 2012 (WISA2012). It divides a multiplication structure into partial products and reconstructs them to share common operands between previous and next partial products. However, there is still room for improvement; therefore, we propose a finely designed operand-caching mode to minimize useless memory accesses when the first row is changed. Finally, we reduce the number of memory access instructions and boost the speed of the overall multiprecision multiplication for public key cryptography.