전력 분석에 안전한 AES에 대한 새로운 종류의 충돌쌍 공격

김희석,박학수,홍석희,Kim, HeeSeok,Park, Hark-Soo,Hong, Seokhie 한국정보처리학회 2013 정보처리학회논문지. 컴퓨터 및 통신시스템 Vol.2 No.9

본 논문에서는 일차 전력 분석에 안전한 AES의 마스킹 기법을 분석할 수 있는 새로운 충돌쌍 공격을 제안한다. 제안하는 충돌쌍 공격은 기존 충돌쌍 공격의 단점인 선택 평문 공격의 단점을 극복하고 기지 평문 공격이 가능하도록 구성되어진다. 또한 제안하는 분석기법은 이차 전력분석보다 효율적이며 최근 제안된 충돌쌍 공격에 요구되는 파형 개수에 비해 약 1/27.5배의 파형만을 요구한다. 논문에 포함된 실험 결과들은 이러한 사실을 뒷받침한다. 본 논문에서는 또한 새로운 분석 기법과 함께 이 방법을 방어할 수 있는 간단한 대응방법을 소개하도록 한다. This paper introduces a new collision attack on first-order masked AES. This attack is a known plaintext attack, while the existing collision attacks are a chosen plaintext attack. In addition, our method is more efficient than the second-order power analysis and requires about 1/27.5 power measurements by comparison with the last collision attack. Some experiment results of this paper support this fact. In this paper, we also introduce a simple countermeasure, which can protect against our attack.

점성감쇠기를 이용하는 흡수경계의 성능 향상에 관한 연구

김희석,이종세,Kim, Hee-Seok,Lee, Jong-Seh 한국전산구조공학회 2007 한국전산구조공학회논문집 Vol.20 No.5

본 논문에서는 무한영역을 유한의 요소영역으로 표현하는데 있어서 가장 폭넓게 사용되는 점성감쇠기를 이용한 흡수경계의 성능을 향상시키기 위한 연구를 수행하였다. 2차원 평면조화파동방정식을 이용하여 응력파의 경계면으로의 입사각에 따른 흡수경계조건을 최적화 하였으며, Miller 등이 제안한 반무한 탄성체에서의 주기하중에 의한 전파식을 최적화된 점성감쇠기를 이용한 흡수경계 조건식에 삽입한 후 방정식의 해를 직접 비교함으로서 해석적인 검증을 수행하였다. 또한 수치적 검증을 위해 유한요소법을 사용하여 Miller 등의 파진행 문제를 구현하였으며, 이때 흡수경계를 구현하기 위해 점성감쇠기를 부착시킨 수치모형에서의 변위와 파의 도달시간을 고려하여 반사파의 영향을 제거시킨 수치모형에서의 변위를 비교함으로써 흡수율을 산정하였다. 흡수율은 수치모형의 경계와 내부점에 대해 각각 산정되었으며 이를 통해 수치적 검증을 수행하였다. In this paper an analytical study is carried out to improve the capacity of absorbing boundary using dashpot, one of the most widely used absorbing boundaries in FEM. Using 2-D harmonic plane wave equation, absorbing boundary condition is modified to maximize its capacity according to the incident angle. Validity of the absorbing boundary conditions which is modified is investigated by adopting the solution of Miller and Pursey. The Miller and Pursey's problem is then numerically simulated using the finite element method. The absorption ratios are calculated by comparing the displacements at the absorbing boundary to those at the free field without the absorbing boundary. The numerical study is carried out through comparison of displacement at the interior region and the boundary of the numerical model.

PLD 설계용 툴 개발에 관한 연구

김희석,원충상,Kim, Hee-Suk,Won, Chung-Sang 한국정보처리학회 1994 정보처리논문지 Vol.1 No.3

본 논문에서는 디지틀 회로를 PLD 소자로 설계하는 PLD 설계용 툴인 PLD Designer 을 개발하였다. PLD Designer는 FSM(finite state machine)의 상태수가 제한적(20개 미만)일 경우, 상태표로부터 부울식을 추출할 수 있는 상태 그래픽 편집기(state graphic editor)와 상태 그래픽 편집기에서 생성된 부울식에 적합한 PLD 소자 (PAL 16R4, PAL22V10, GAL16V8 등)를 선정하여 핀 할당을 실현하는 핀 맵 편집기(pin map editor)로 구성되어 있다. 또한 핀 맵 편집기는 fuse map, checksum, JEDEC화일을 생성하며 PLD 디바이스 구현에 사용한다. 생성된 부울식을 검증하기 위해 테스트 벡터 (test vector) 생성 알고리즘을 개발하였으며 PLD Designer에 의해 생성된 JEDIC화일 과 PALASM의 JEDEC화일과 비교한 결과 동일함을 입증하였다. In this paper, we have developed a PLD Designer which is a design tool for digital circuits design using PLD device. PLD designer consists of a state graphic editor to extract boolean equations from state table within 20 states of FSM and a pin map editor to assign pin map for PLD device(PAL16R4, PAL22V10, GAL16V8, etc), which is suitable for extracted boolean equations. Also pin map editor generates a necessary JEDEC file to implement PLD device by using fuse map and checksum algorithm. To verify extracted boolean equation, we have developed simulation test vector generation algorithm. The results of JEDEC files generated by PLD designer is same with the results of JEDEC files generated by PALASM.

해상 근무 승무원의 수학적 전신진동 해석 모델에 관한 연구

김희석,김홍태,박진형,Kim, Hee-Seok,Kim, Hong-Tae,Park, Jin-Hyoung 대한인간공학회 2003 大韓人間工學會誌 Vol.22 No.1

The resonance behaviour needs be understood to identify the mechanisms responsible for the dynamic characteristics of human body, to allow for the non-linearity when predicting the influence of seating dynamics, and to predict the adverse effects caused by various magnitudes of vibration. However, there are currently no known studies on the effect of vibration magnitude on the transmissibility to thoracic or lumbar spine of the seated person, despite low back pain(LBP) being the most common ailment associated with whole-body vibration. The objective of this paper is to develop a proper mathematical human model for LBP and musculoskeletal injury of the crew in a maritime vehicle. In this study, 7 degree-of-freedom including 2 non-rigid mass representing wobbling visceral and intestine mass, is proposed. Also, when compared with previously published experimental results, the model response was found to be well-matching. When exposed to various of vertical vibration, the human model shows appreciable non-linearity in its biodynamic responses. The relationships of resonance for LBP and musculoskeletal injury during whole-body vibration are also explained.

시간제약 조건을 고려한 CPLD 기술 매핑 알고리즘 개발

김희석,변상준,Kim, Hi-Seok,Byun, Sang-Zoon 대한전자공학회 1999 電子工學會論文誌, C Vol.c36 No.6

In this paper, we propose a new technology mapping algorithm for CPLD under time constraint. In our technology mapping algorithm, a given logic equation is constructed as the DAG type, then the DAG is reconstructed by replicating the node that outdegree is more than or equal to 2. As a result, it makes delay time and the number of CLBs to be minimized. Also, after the number of multi-level is defined and cost of each nodes is calculated, the graph is partitioned in order to fit to k that is the number of OR term within CLB. The partitioned nodes are merged through collapsing and bin packing is performed in order to fit to the number of OR term within CLB. In the results of experiments to MCNC circuits for logic synthesis benchmark, we can shows that proposed technology mapping algorithm reduces delay time and the number of CLBs much more than the existing tools of technology mapping algoritm. 본 논문에서는 시간제약 조건을 고려한 새로운 CPLD 기술매핑 알고리즘을 제안한다. 본 기술매핑 알고리즘은 주어진 논리식을 DAG로 구성하여 각 노드를 검색한 후, 출력에지가 2이상인 노드를 분할하지 않고 노드를 복제(replication)하여 DAG을 재구성함으로써 지연시간과 CLB의 개수가 최소화 되도록 하였다. 즉, 시간제약 조건과 소자의 지연시간을 이용하여 그래프 분할이 가능한 다단의 수를 정한다. 그런 다음 각 노드의 초기비용과 전체비용을 계산하여 CLB의 k-OR텀수보다 비용이 초과되는 노드를 분할하여 서브그래프를 구성한다. 분할된 서브그래프들은 collapsing을 통해 노드들을 병합하고 네 번째로 주어진 소자의 CLB안에 있는 k-OR텀 개수에 맞게 Bin packing를 수행하였다. 본 논 문에서 제안한 기술매핑 알고리즘을 MCNC 논리합성 벤치마크 회로들에 적용하여 실험한 결과 기존의 기술 매핑 툴인 TEMPLA에 비해 CLB의 개수가 18% 감소되었다.

소에 있어서 다배란 유기에 영향을 미치는 요인에 관한 연구

김희석,김영진,이종문,이근상,정길생 ( H . S . Kim,Y . J . Kim,J . M . Lee,K . S . Lee,K . S . Chung ) 한국축산학회 1985 한국축산학회지 Vol.27 No.4

These experiment were conducted to investigate the effects of the kinds and dosages of gonadotropins, breed, parity, body weight, season, milk yield and serum total cholesterol (T-CHO) levels on ovarian responses in superovulated cattle. The number of follicles and corpus luteum (CL) per head in superovulated cattle were 6.6±080 and 4.8±0.72. Superovulation with FSH resulted in ovarian response more than that of PMSG and the best ovarian response in parity, body weight and season was showed in heifer, 350-450㎏ and autumn, respectively. In the calving-superovulation interval, below 5 month was showed poor ovarian response. In the lactating dairy cows, the best ovarian response was showed in below 15㎏/day of milk yield and decreased as milk yield increased. In the serum T-CHO levels, the best result was obtained from more than 150㎎/100㎖ and the ovarian response increased as the serum T-CHO levels increased.

소에 있어서 비외과적 채란 및 이식에 관한 연구

김희석,오성종,양보석,이근상,정길생 ( H . S . Kim,S . J . Oh,B . S . Yang,K . S . Lee,K . S . Chung ) 한국축산학회 1985 한국축산학회지 Vol.27 No.4

These experiments were conducted to investigate the effects of hormone treatment, serum total cholesterol (T-CHO) levels and flushing site on ova recovery and transfer method on pregnancy rate in cattle. The best number of ova recovered among PMSG treatments was showed in PMSG 3000IU + PGF₂α 25㎎ and the number of ova recovered and recovery rate of FSH were more than those of PMSG. In serum T-CHO levels, the case of more than 150㎎/100㎖ in superovulated cattle showed higher than those of below 150㎎/100㎖ in ova recovery. The recovery rate of uterine body was slightly better than that of each uterine horn. Cleavage stage of ova recovered on 7 to 8 days following estrus were mostly morulae and blastocysts and the average normal rate of ova recovered was 78.7%. The mean length of the cycle preceeding PMSG and FSH treatment were 52.38±20.90 and 23.83±13.26 days, respectively. When PGF₂α was administrated after flushing, the day of interval from the induced estrus to spontaneous estrus tended to shorten. The pregnancy rate in single, A1 + single and twin was 22.0, 35.7 and 35.6%, respectively.

한우정액의 이화학적 성장에 관한 연구

김희석,정길생 ( Hee S . Kim,Kil S . Chung ) 한국축산학회 1979 한국축산학회지 Vol.21 No.4

This experiment was carried out to clarify the physical and chemical characteristics of whole semen, seminal plasma and spermatozoa in Korean native bull. The results obtained were summarized as follows: 1. Semen volume, sperm density and total number of sperm were on the average 5.9±0.23 ㎖, 10.74±0.71 10^8/㎖ and 63.43±2.13 10^8 /ejaculate respectively. All of them were higher in Spring and Winter than in Summer and Autumn. 2. The pH value, viscosity, specific gravity and dry weight of whole semen were 6.5±0.03, 5.5±0.43, 1.036±0.002 and 9.9±0.20% respectively. The pH value was lowest in Summer while the viscosity and specific gravity were highest in winter and the dry weight was heaviest in Spring. 3. The mean values of sodium in whole semen, seminal plasma and spermatozoa were 195.87±76.8 ㎎/100㎖, 197.36±34.94㎎/100㎖ and 56.46±24.75γ/10^8 and those of potassium were 183.75±42.32 ㎎/100m1, 191.59±43.23 ㎎/100 ㎖ and 56.91±18.85 γ/10^8 respectively. The mean values of chloride were 353.23±44.82 ㎎/100 ㎖, 225.43±30.68 ㎎/100㎖ and 136.08±13.02γ/10^8 and those of total phosphorus were 60.37±6.21㎎/100㎖. 33.19±2.77 ㎎/100㎖ and 25.03±2.14 γ/10^8 respectively. 4. Concentrations of fructose and citric acid in whole semen were 393.60±77.55 ㎎/100 ㎖ and 552.58±67.12 ㎎/100 ㎖, in seminal plasma 722.40±181.14 ㎎/100 ㎖ and 649.06±61.82 ㎎/100 ㎖, and in spermatozoa 46.19±8.81 γ/10^8 arid 110.64±8.32γ/10^8. 5. Average total nitrogen values in whole semen, seminal plasma and spermatozoa were 1577.95±86.92 ㎎/100㎖, 1266.1±198.92 ㎎/100 ㎖ and 536.84±119.34γ/10^8, non-protein nitrogen in these were 351.8±99.21 ㎎/100 ㎖, 374.9±73.88 ㎎/100 ㎖ and 159.20±29.29 γ/10^8, and urea were 26.89±8.29 ㎎/100 ㎖, 38.24±10.25 ㎎/100 ㎖ and 5.94±1.45γ/10^8 respectively. 6. Total amino acid in whole semen, seminal plasma and spermatozoa were 8474.32 ㎎/100m1, 6901.73 ㎎/100 ㎖ and 3220.72γ/10^8 respectively. 7. Average values of the total lipid in whole semen, seminal plasma and spermatozoa were 702.4±53.9 ㎎/100㎖, 492.5±6.1 ㎎/100 ㎖ and 322.2±56.5 γ/10^8, phospho lipid 130.9±8.8 ㎎/100 ㎖, 83.7±6.8 ㎎/100 ㎖ and 70.5±9.9 γ/10^8, and total. cholesterol 282.4±41.3 ㎎/100 ㎖, 189.8±7.1 ㎎/100 ㎖ and 81.6±13.4γ/10^8 respectively.

고객 감동의 시작 원투원 서비스

김희석,Kim, Hui-Seok 한국데이터베이스진흥원 2000 디지털콘텐츠 Vol.3 No.-

고객 한사람 한사람을 분리하여 별도로 접근하지 않고서는 완벽한 고객 서비스를 제공할 수 없다. 고객을 생산라인의 일개 부품처럼 취급한다면 충실한 고객을 기대하기 어렵다. 반면에 어떤 회사가 고객을 마치 VIP처럼 대접할 경우 그 고객은 더욱 충실한 고객이 된다. 이글에서는 인터넷 원투원 서비스와 구축 방안에 대해 살펴본다.

Practical Second-Order Correlation Power Analysis on the Message Blinding Method and Its Novel Countermeasure for RSA

김희석,홍석희,Tae Hyun Kim,Joong Chul Yoon 한국전자통신연구원 2010 ETRI Journal Vol.32 No.1

Recently power attacks on RSA cryptosystems have been widely investigated, and various countermeasures have been proposed. One of the most efficient and secure countermeasures is the message blinding method, which includes the RSA derivative of the binary-with-random-initial-point algorithm on elliptical curve cryptosystems. It is known to be secure against first-order differential power analysis (DPA); however, it is susceptible to second-order DPA. Although second-order DPA gives some solutions for defeating message blinding methods, this kind of attack still has the practical difficulty of how to find the points of interest, that is, the exact moments when intermediate values are being manipulated. In this paper, we propose a practical second-order correlation power analysis (SOCPA). Our attack can easily find points of interest in a power trace and find the private key with a small number of power traces. We also propose an efficient countermeasure which is secure against the proposed SOCPA as well as existing power attacks.