• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.581-584
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• 2004

Currently, there are many subscriber access networks: PSTN, ADSL, Cellular Network, IMT200 and so on. To these service providers that provide above network service, it is important that they authenticate and authorize legal subscribers and account for their usage. At present, There exist the several protocols that Support AAA(Authentication, Authorization and Accounting) service : RADIUS, Diameter, TACACS+. Nowadays, RADIUS has used for AAA service widely. It has been extended to support other access network environment. So, we extend RADIUS to support environment of Mobile IPv6. Mobile IPv6 uses IPsec as a security mechanism, basically. But, IPsec is a heavy security technology for small, portable, mobile device. Especially, it is serious at IKE, the subset of IPsec. IKE is a key distribution protocol that distributes the key to the endpoints of IPsec. In t:lis paper, we extend RADIUS to support environment of Mobile IPv6 and simplify the IKE phase of IPsec by AAA system distributing the keys by using its security communication channel. Namely, we propose the key distribution method for IPsec SA establishment between mobile node and home agent. The suggested method was anticipated to be effective at low-power, low computing deyice. Finally, end users feel the faster authentication.

• 한국위성정보통신학회논문지
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• 제12권4호
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• pp.152-156
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• 2017

본 논문은 양자 키 분배 시스템에서의 보안성을 증폭시키기 위한 랜덤 보안성 증폭의 개념을 소개한다. 양자 오류 정정과 보안 사이의 관계를 이용하여 보안성 증폭을 제공하는 것을 보인다. 또한 보안성 증폭 측면에서 랜덤 보안성 증폭이 기존 유니버셜 해쉬 함수만을 이용한 것보다 나은 보안성을 제시한다는 것을 보인다. QKD의 대표적인 예인 BB84 프로토콜을 이용하여 유니버셜 해시 함수가 보안성을 강화하는 과정을 설명한다. 마지막으로 제안한 랜덤 보안성 증폭과 기존 방식이 양자 QKD 채널에서 키 생성률에 따른 보안성을 비교한다.

• Carbon letters
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• 제13권3호
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• pp.133-138
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• 2012

According to kinetic mechanisms, liquid phase polymerization and solid phase polymerization are different in acrylonitrile (AN) polymerization, and so the relationship between the contribution ratio and molecular weight distribution (MWD) was obtained through theoretic analysis. The precipitation homopolymerization of AN was carried out in a mixture solution of dimethyl sulfoxide (DMSO) and water at $50{\sim}65^{\circ}C$ using ${\alpha}$,${\alpha}^{\prime}$-azobisisobutyronitrile as an initiator. The contribution ratio decreased and approached 0; the MWD also decreased and approached 2 with the increase of the $H_2O$/DMSO ratio from 10/90 to 90/10. The experimental data were found to coincide well with the theoretical equation derived from the mechanisms.

• 한국인터넷방송통신학회논문지
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• 제18권5호
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• pp.111-116
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• 2018

본 논문은 양자 키 분배 시스템에서의 보안성을 증폭시키기 위한 유니버셜 랜덤 해쉬 함수의 개념을 소개하고 양자 오류 정정과 보안 사이의 관계를 이용하여 보안성 증폭을 제공하는 것을 보인다. 또한, 보안성 증폭 측면에서 접근 방식이 위상 오차 보정 방식을 소개하며 위상 오차 방식이 다른 방식보다 더 나은 보안성을 제시한다는 것을 보인다. 양자 키 분배의 대표적인 예인 BB84 프로토콜을 이용하여 유니버셜 해시 함수가 보안성을 강화하는 과정을 설명한다. 마지막으로 랜덤 프라이버시 증폭을 사용하는 BB84 프로토콜이 동일한 오류율을 가지는 Mayers의 성능보다 높은 키 레이트를 가지는 것을 보여 보안성이 강화된 것을 확인한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권6호
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• pp.2518-2533
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• 2020

In wireless sensor networks, adversaries may physically capture sensor nodes on the fields, and use them to launch false positive attacks (FPAs). FPAs could be conducted by injecting forged or old sensing reports, which would represent non-existent events on the fields, with the goal of disorientating the base stations and/or reducing the limited energy resources of sensor nodes on the fields. Researchers have proposed various mitigation methods against FPAs, including the statistical en-route filtering scheme (SEF). Most of these methods are based on key pre-distribution schemes and can efficiently filter injected false reports out at relay nodes through the verification of in-transit reports using the pre-distributed keys. However, their filtering power may decrease as time goes by since adversaries would attempt to capture additional nodes as many as possible. In this paper, we propose an adaptive key distribution method that could maintain the security power of SEF in WSNs under such circumstances. The proposed method makes, if necessary, BS update or re-distribute keys, which are used to endorse and verify reports, with the consideration of the filtering power and energy efficiency. Our experimental results show that the proposed method is more effective, compared to SEF, against FPAs in terms of security level and energy saving.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5218-5233
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• 2018

The coexisting wireless body area networks (WBAN) is a very challenging issue because of strong inter-networks interference, which seriously affects energy consumption and spectrum utilization ratio. In this paper, we study a power control strategy with nearest neighbor nodes distribution for coexisting WBAN based on stochastic geometry. Using homogeneous Poisson point processes (PPP) model, the relationship between the transmission power and the networks distribution is analytically derived to reduce interference to other devices. The goal of this paper is to increase the transmission success probability and throughput through power control strategy. In addition, we evaluate the area spectral efficiency simultaneously active WBAN in the same channel. Finally, extensive simulations are conducted to evaluate the power control algorithm.

• 정보보호학회논문지
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• 제1권1호
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• pp.47-65
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• 1991

개인정보에 바탕을 둔 키 분배방식은 공개 키 분배상식에서의 공개키 인증문제나 통신량 집중현상을 자연스럽게 해결할 수 있는 매우 효율적인 방법으로 널리 연구되고 있다. 특히 사전통신 없이도 안전하게 세션키를 공유할 수 있는 비대화형의 키 분배방식은 일방통신만이 허용되는 E-mail 등에서 보안 서비스를 제공하는데 중요한 역할을 한다. 본 논문에서는 기존에 제안된 대표적인 방식들을 분석하고 안전성이나 효율성 등에 있어서 가능한 개선방안들을 제시하고자 한다. 특히 기존에 제안된 대부분의 비대화형 방식에서 공통적으로 겪고 있는 사용자간의 결탁문제를 해결한 매우 효율적인 방법으로 최근에 제안된 Maurer-Yacobi 방식을 분석하여 그 문제점을 제기하고 이를 해결할 수 있는 개선방안도 제시한다.

• 융합보안논문지
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• 제8권1호
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• pp.143-152
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• 2008

Sensor networks have a wide spectrum of military and civil applications, particularly with respect to security and secure keys for encryption and authentication. This thesis presents a new centralized approach which focuses on the group key distribution with revocation capability for Wireless Sensor Networks. We propose a new personal key share distribution. When utilized, this approach proves to be secure against k-number of illegitimate colluding nodes. In contrast to related approaches, our scheme can overcome the security shortcomings while keeping the small overhead requirements per node. It will be shown that our scheme is unconditionally secure and achieves both forward secrecy and backward secrecy. The analysis is demonstrated in terms of communication and storage overheads.

• Geomechanics and Engineering
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• 제23권5호
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• pp.431-439
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• 2020

Soil-water retention curve (SWRC) contains key information for the application of unsaturated soil mechanics principles to engineering practice. The SWRC variables are commonly used to describe the hydro-mechanics of soils. Generally, these parameters are determined using the graphical method which can be time consuming. The SWRC is highly dependent on the pore size distribution (PSD). Theoretically, the PSD obtained by mercury intrusion porosimetry test can be used to determine some SWRC variables. Moreover, the relationship between SWRC and shrinkage curve has been investigated. A new method to determine total SWRC variables directly without curve-fitting procedure is proposed. Substituting the variables into linear SWRC equations construct SWRC. A good agreement was obtained between predicted and measured SWRCs, indicating the validity of the proposed method for unimodal SWRC.

• 한국콘텐츠학회논문지
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• 제4권3호
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• pp.53-60
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• 2004

본 논문에서는 Threshold PKC를 이용하여 패스워드 사전공격에 안전한 사용자인증 및 키분배 방법을 제안한다. 신뢰기관의 개인키를 (t,n) 비밀분산을 이용하여 n개의 서버에 분산 저장시키고 서며가 사용자를 인증할 때 t개 이상의 서버가 협력하여 사용자의 패스워드 검증자를 복원한다