• Journal of Korea Society of Industrial Information Systems
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• v.7 no.3
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• pp.1-8
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• 2002

Modular Multiplication in Galois Field GF(2/sup m/) is a basic operation for many applications, particularly for public key cryptography. This paper presents a new architecture that can process modular multiplication on GF(2/sup m/) per m clock cycles using a cellular automata. Proposed architecture is more efficient in terms of the space and time than that of systolic array. Furthermore it can be efficiently used for the hardware design for exponentiation computation.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.05a
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• pp.331-335
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• 2006

인터넷의 발달과 사용자 증가로 인해 IETF는 다양한 네트워크와 프로토콜 상에서 안전하고 신뢰성 있는 사용자 인증을 위해 AAA를 제안하였다. 그러나 AAA의 최신 버전인 Diameter 표준의 인증 방식은 상호인증과 부인방지를 제공하지 않는다. 이러한 Diameter의 인증을 보완하기 위해 공개키를 이용한 AAA 인증 방식이 제안되었으나, 통신과 연산의 오버헤드로 인해 이동 노드에 적용이 어렵다. 이러한 단점을 극복한 ID 기반 AAA 인증 방식이 제안 되었으나 공모공격과 위장공격으로부터의 취약점을 가진다. 이 논문에서는 공모공격과 위장공격에 안전하고, 계산적 전력적 능력이 부족한 이동 노드의 연산량을 감소시키는 새로운 ID기반 AAA인증 방식을 제안한다. 제안한 방식의 검증을 위해 기존 방식을 비교 평가하여 암호학적인 안전성과 연산량의 효율성을 검증한다. 제안 방식은 이동 노드의 인증시 2개의 난수를 생성하여 안전성을 제공하며, Mobile 노드의 지수연산을 줄임으로 계산 전력적 측면에서 효율적이고 서버의 성능에 따라 인증 수행 시간을 감소 시켜 끊김 없는 서비스를 제공할 수 있는 장점을 갖는다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.8
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• pp.30-37
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• 2007

An exponentiation in $GF(2^m)$ is a basic operation for several algorithms used in cryptography, digital signal processing, error-correction code and so on. Existing hardware implementations for the exponentiation operation organize by Right-to-Left method since a merit of parallel circuit. Our paper proposes a polynomial exponentiation structure with a trinomial that is organized by Left-to-Right method and that utilizes a weakly dual basis. The basic idea of our method is to decrease time delay using precomputation tables because one of two inputs in the Left-to-Right method is fixed. Since $T_{sqr}$ (squarer time delay) + $T_{mul}$(multiplier time delay) of ow method is smaller than $T_{mul}$ of existing methods, our method reduces time delays of existing Left-to-Right and Right-to-Left methods by each 17%, 10% for $x^m+x+1$ (irreducible polynomial), by each 21%, 9% $x^m+x^k+1(1, by each 15%, 1% for $x^m+x^{m/2}+1$.

• Science of Emotion and Sensibility
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• v.3 no.1
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• pp.63-71
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• 2000

본 연구에서는 20대의 건강한 남자대학생 45명을 대상으로 작업조건(안정상태, 연산작업상태, 휴식상태, 반복연산작업상태, 연산작업후 아정상태)과 연산레벨(연산작업의 난이도)에 따른 생리신호의 측정을 위한 실험 프로토콜을 제안하고 측정된 생리신호에 대한 분석을 하였다. 연산작업에 대하여 측정된 파라메터에 대하여 1) 정규분포화를 위한 파라메터의 변환 2) 파라메터간의 산관관계의 조사 3) 연산작업에 대한 파라메터의 표준화 4) 작업조건과 연산레벨에 대한 파라메터의 차이에 대한 유의성검정을 하여 연산스트레스를 평가할 수 있는 파라메터를 추출하였다. 연산작업시의 파라메터는 안정산태의 파라메터와 유의적인 차이를 나타내어 연구에 사용된 연산작업이 생리신호의 변화를 발생시키는 것으로 밝혀졌고 연산작업후의 휴식상태에서 측정된 대부분의 파라메터의 갓이 연산작업전의 안정상태의 파라메터의 통계적으로 유의적인 차이가 없어서 본 연구에 사용된 연산작업은 단기적 스트레스를 유발하는 것으로 밝혀졌다. 그리고, 동일한 연산레벨에 대한 연산작업을 반복하더라도 파라메터의 값은 처음으로 연산작업을 할 때의 파라메터의 값과 유의적인 차이가 없었다. 그러나, 연산레벨에 따라서는 Heart Rate, HRV의 LF/HF, HRV의 MF/(LF+HF), Return Map의 분산, 코끝의 Mean Temperature, GSR-Mean과 호흡수는 차이가 있는 것으로 밝혀졌다. 따라서 이들 파라메터를 사용하면 연산스트레스의 강도를 지수화할 수 있을 것이다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.1
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• pp.113-119
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• 2004

Exponentiation is widely used in practical applications related with cryptography, and as the discrete log is easily solved in case of a low exponent n, a large exponent n is needed for a more secure system. However. since the time complexity for exponentiation algorithm increases in proportion to the n figure, the development of an exponentiation algorithm that can quickly process the results is becoming a crucial problem. In this paper, we propose a parallel exponentiation algorithm which can reduce the number of rounds with a fixed number of processors, where the field elements are in GF($2^m$), and also analyzed the round bound of the proposed algorithm. The proposed method uses window method which divides the exponent in a particular bit length and make idle processors in window value computation phase to multiply some terms of windows where the values are already computed. By this way. the proposed method has improved round bound.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.183-195
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• 2012

We propose a variable-latency Decimal Floating Point(DFP) adder which adopts the dual data path scheme. It is to speed addition and subtraction of operand that has identical exponents. The proposed DFP adder makes use of L. K. Wang's operand alignment algorithm, but operates through high speed data-path in guaranteed accuracy range. Synthesis results show that the area of the proposed DFP adder is increased by 8.26% compared to the L. K. Wang's DFP adder, though critical path delay is reduced by 10.54%. It also operates at 13.65% reduced path than critical path in case of an operation which has two DFP operands with identical exponents. We prove that the proposed DFP adder shows higher efficiency than L. K. Wang's DFP adder when the ratio of identical exponents is larger than 2%.

• Journal of the Korea Society of Computer and Information
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• v.8 no.3
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• pp.113-123
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• 2003

Many researches on the application of neural networks for making financial index prediction have proven their advantages over statistical and other methods. In this paper, a neural network model is proposed for the Buying, Holding or Selling timing prediction in stocks by the price index of stocks by inputting the closing price and volume of dealing in stocks and the technical indexes(MACD, Psychological Line). This model has an equalized multi-layer arithmetic function as well as the time series prediction function of backpropagation neural network algorithm. In the case that the numbers of learning data are unbalanced among the three categories (Buying, Holding or Selling), the neural network with conventional method has the problem that it tries to improve only the prediction accuracy of the most dominant category. Therefore, this paper, after describing the structure, working and learning algorithm of the neural network, shows the equalized multi-layer arithmetic method controlling the numbers of learning data by using information about the importance of each category for improving prediction accuracy of other category. Experimental results show that the financial index prediction using the equalized multi-layer arithmetic neural network has much higher correctness rate than the other conventional models.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.4
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• pp.293-304
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• 2005

In this paper, we research on job migration in a grid computing environment with cactus and MPICH-C2 based on Globus. Our concepts are to perform job migration by finding the site with plenty of computational resources that would decrease execution time in a grid computing environment. The Migration Manager recovers the job from the checkpointing files and restarts the job on the migrated site. To select a migrating site, the proposed method considers system's performance index, cpu's load, network traffic to send migration job tiles and the execution time predicted on a migration site. Then it selects a site with maximal performance gains. By selecting a site with minimum migration time and minimum execution time. this approach implements a more efficient grid computing environment. The proposed method Is proved by effectively decreasing total execution time at the $K\ast{Grid}$.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1003-1006
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• 2004

본 논문에서는 몽고메리 모듈러 곱셈(Montgomery Modular Multiplication) 알고리즘을 이용하여 효율적인 모듈러 곱셈기를 제안한다. 본 논문에서 제안한 곱셈기는 프로그램 가능한 셀룰라 오토마타(Programmable Cellular Automata, PCA)를 기반의 구조로 설계되어 하드웨어 복잡도를 줄이고, 곱셈시 몽고메리 알고리즘을 이용하여 일반적인 나눗셈 없이 모듈러 연산을 수행하여 시간 복잡도를 최소화 한다. 제안된 곱셈기는 시간적, 공간적인 면에서 간단하고 효과적으로 구성되어 지수연산을 위한 하드웨어의 하부구조나 오류 수정 코드(Error Correcting Code)의 연산에서 효율적으로 이용될 수 있을 것이다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.10 no.4
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• pp.47-57
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• 2000

This paper proposes efficient anonymous fingerprinting with improved automatic identification of redistributors in electronic commerce of digital contents. The proposed scheme by Domingos in Eletronic Letters is inefficient in electronic commerce, because of pass numbers in registration protocol and exponential computations in identification protocol. Our scheme is reduced 2-pass in registraton protocol and is required only 1 time exponential computation than his in identification protocol. According to electronic commerce of digital contents used in ordinary life, our schemes values are increased.