• 정보보호학회논문지
• /
• 제12권5호
• /
• pp.95-105
• /
• 2002

본 논문에서는 공개키 암호 시스템에서 인증, 키 교환 및 전자 서명을 위해 사용되는 RSA 공개키 암호 알고리즘의 효율적인 하드웨어 구현 방법에 대해 기술하였다. RSA 공개키 알고리즘은 모듈러 멱승 연산에 의해 계산되어지며, 모듈러 멱승 연산은 반복적인 모듈러 곱셈 연산을 필요로 한다. 모듈러 곱셈 구현을 위한 많은 알고리즘 중, 하드웨어 구현의 효율성 때문에 Montgomery 알고리즘이 많이 사용되어지고 있다. 지금까지 몽고메리 알고리즘을 이용하여 고성능의 RSA 암호회로를 설계하는 연구는 많이 수행되어 왔으나, 대부분의 연구가 시스템의 고성능을 위한 연산 시간의 감소에 중점을 두고있다. 하드웨어 구현에 제한이 있는 시스템에서 하드웨어 설계 시 가장 고려해야 할 사항은 시스템의 성능과 면적을 고려한 설계이다. 이러한 이유로, 본 논문에서는 기존의 Montgomery 알고리즘을 저면적 회로에 적합한 구조로 개선하였으며, 개선된 알고리즘을 이용하여 ETRI에서 개발한 스마트 카드용 에뮬레이팅 시스템인 IESA 시스템에 적용하여 검증하였다.

• 산업경영시스템학회지
• /
• 제38권2호
• /
• pp.40-46
• /
• 2015

The modular assembly system can make it possible for the variety of products to be assembled in a short lead time. In this system, necessary components are assembled to optional components tailor to customers' orders. Budget for inventory investments composed of inventory and purchasing costs are practically limited and the purchasing cost is often paid when an order is arrived. Service cost is assumed to be proportional to service level and it is included in budget constraint. We develop a heuristic procedure to find a good solution for a continuous review inventory system of the modular assembly system with a budget constraint. A regression analysis using a quadratic function based on the exponential function is applied to the cumulative density function of a normal distribution. With the regression result, an efficient heuristics is proposed by using an approximation for some complex functions that are composed of exponential functions only. A simple problem is introduced to illustrate the proposed heuristics.

• 정보처리학회논문지C
• /
• 제10C권4호
• /
• pp.405-412
• /
• 2003

As the XML is approved standard language by the UN, the progress which complemented the XML security has being processed rapidly. In this paper, we design and implement the "XML-Signcryption" as a security mechanism to protect the XML document that can operate between other platforms. The signature and encryption which is the standard specification in W3C needs to be able to proceed them separately. Generally the signature and encryption require four times modular exponential operation, however the signcryption only needed three times modular exponential operation. This will benefit overall system effectiveness in terms of cost. And this scheme offers to convenient the user, because the signature and encryption implement as a single XML format. This tool can save the parsing time as a number of tags is few within a document. And also, in this paper, based on a research of Web Services security, we can apply XML-Signcryption to the SOAP message to provide the security services. Based on the XML-Signcryption scheme which provides confidentiality, integrity, authentication and non-repudiation to the XML document and Web Service security simultaneously.

• 한국정보통신학회논문지
• /
• 제10권2호
• /
• pp.344-352
• /
• 2006

자동으로 암호문과 평문의 수신이 가능한 팩시밀리용 암호통신시스템을 개발하였다. 개발된 암호시스템은 128bit SEED알고리즘을 적용하였으며 1024bit 모듈러, 256bits Exponent의 Diffie-Hellman 키교환방식을 적용하였다. 암호문 고속 전송을 위해 Dual FAX Server를 개발함으로써 실시간 암호통신을 구현하였다. Diffie-Hellman 키교환 시 등록된 시리얼번호를 서로 교환시켜 안전한 키 교환이 가능하게 하였다.

• Nuclear Engineering and Technology
• /
• 제54권12호
• /
• pp.4571-4584
• /
• 2022

The analysis of rapid flow transients in Reactor Coolant Pumps (RCP) is essential for a reactor safety study. An accurate and precise analysis of the RCP coastdown is necessary for the reactor design. The coastdown of RCP affects the coolant temperature and the colloidal crud in the primary coolant. A realistic and kinetic model has been used to investigate the behavior of activated colloidal crud in the primary coolant and steam generator that solves the pump speed analytically. The analytic solution of the non-dimensional flow rate has been determined by the energy ratio β. The kinetic energy of the coolant fluid and the kinetic energy stored in the rotating parts of a pump are two essential parameters in the form of β. Under normal operation, the pump's speed and moment of inertia are constant. However, in a coastdown situation, kinetic damping in the interval has been implemented. A dynamic model ACCP-SMART has been developed for System Integrated Modular and Advanced Reactor (SMART) to investigate the corrosion due to activated colloidal crud. The Fickian diffusion model has been implemented as the reference corrosion model for the constituent component of the primary loop of the SMART reactor. The activated colloidal crud activity in the primary coolant and steam generator of the SMART reactor has been studied for different equilibrium corrosion rates, linear increase in corrosion rate, and dynamic RCP coastdown situation energy ratio b. The coolant specific activity of SMART reactor equilibrium corrosion (4.0 mg s^-1) has been found 9.63×10^-3 µCi cm^-3, 3.53×10^-3 µC cm^-3, 2.39×10^-2 µC cm^-3, 8.10×10^-3 µC cm^-3, 6.77× 10^-3 µC cm^-3, 4.95×10^-4 µC cm^-3, 1.19×10^-3 µC cm^-3, and 7.87×10^-4 µC cm^-3 for ²⁴Na, ⁵⁴Mn, ⁵⁶Mn, ⁵⁹Fe, ⁵⁸Co, ⁶⁰Co, ⁹⁹Mo, and ⁵¹Cr which are 14.95%, 5.48%, 37.08%, 12.57%, 10.51%, 0.77%, 18.50%, and 0.12% respectively. For linear and exponential coastdown with a constant corrosion rate, the total coolant and steam generator activity approaches a higher saturation value than the normal values. The coolant and steam generator activity changes considerably with kinetic corrosion rate, equilibrium corrosion, growth of corrosion rate (ΔC/Δt), and RCP coastdown situations. The effect of the RCP coastdown on the specific activity of the steam generators is smeared by linearly rising corrosion rates, equilibrium corrosion, and rapid coasting down of the RCP. However, the time taken to reach the saturation activity is also influenced by the slope of corrosion rate, coastdown situation, equilibrium corrosion rate, and energy ratio β.