• 제목/요약/키워드: key exchange

검색결과 777건 처리시간 0.026초

PKINIT기반의 Kerberos 인증과 키 교환에 관한 연구 (A study on Kerberos Authentication and Key Exchange based on PKINIT)

  • 신광철;정일용;정진욱
    • 정보처리학회논문지C
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    • 제9C권3호
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    • pp.313-322
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    • 2002
  • 본 논문에서는 IETF CAT Working Group에서 발표한 PKNIT 기반의 인증서비스를 향상시킨 Kerberos 인증 메커니즘을 제안한다. PHNIT기반의 X.509, BS/DNS를 적용하여 영역간의 서비스를 제공하는 인증과 키 교환방식으로 DNS를 통해 외부영역의 위치를 탐색하고 X.509 디렉토리 인증 시스템을 적용, 영역간 체인(CertPath)으로 DNS 서버로부터 공개키를 획득하여 다른 영역을 인증하도록 하였다. 영역간 인증과 키 교환은 Kerberos의 관용키 암호방식을 사용하고 세션 연결은 공개키 방식에 기반을 둔 X.509를 연동시키기 위하여 디렉토리서비스를 이용하였다. 이로써 Client를 확인하기 위한 임의 난수 키($K_{rand}$) 생성과 이로 인한 이중 암호화 과정을 배제하였으며 통신상의 Overload를 감소시키는 효과와 인증절차의 간소화를 가지는 Kerberos 시스템을 설계하였다.

인증 URL 기반의 스마트 포스터 인증기법 (Smart Poster Authentication Scheme based on Authentication URL)

  • 이재철;박창섭
    • 융합보안논문지
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    • 제14권7호
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    • pp.91-99
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    • 2014
  • NFC(Near Field Communication)는 13.56MHz 주파수 대역에서 기기 간 데이터 교환 무선 통신기술이다. NFC Forum에서는 NFC Device와 NFC Tag간 데이터 교환을 위한 메시지 형식인 NDEF(NFC Data Exchange Format), 메시지 내의 탑재 가능한 레코드 유형을 정의한 NFC RTD(Record Type Definition), 기존의 종이포스터를 대체할 Smart Poster RTD, 레코드의 진위성과 무결성을 보장하기 위한 Signature RTD를 정의하였다. 그러나 기존 스마트 포스터 인증기법은 가장 빈번하게 일어나는 스마트 포스터 인증 과정에서 방대한 보안 기반구조인 PKI(Public Key Infrastructure) 및 인증서를 통해 스마트 포스터의 공개키 유효성을 확인하는 과정과 인증경로 상에 있는 인증서를 포함한다는 문제점을 가지고 있다. 따라서 본 논문에서는 스마트 포스터 인증과정에서 PKI와 인증서를 사용하지 않고 인증 URL, 서명, 공개키를 통해 스마트 포스터의 공개키의 유효성을 확인하여 스마트 포스터를 인증하는 기법을 제안하고 구현하였다.

IEEE 802-11i의 상호인증과 키 생성 및 교환 메커니즘 분석 (Analysis of Mutual Authentication, Key generation and Key exchange mechanism of IEEE 802.11i)

  • 박지혜;문일현;이옥연;김창범
    • 한국정보보호학회:학술대회논문집
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    • 한국정보보호학회 2003년도 하계학술대회논문집
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    • pp.249-253
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    • 2003
  • 기존의 무선 랜의 보안상의 문제점들을 해결하기 위하여 사용자와 인증자사이의 상호인증과 키를 교환하는 메커니즘이 요구된다. 이것을 보안하기 위해 IEEE 802.11i에서 키 체계와 4-Way Handshake를 제안하였다. 본 논문에서 언급되는 키 생성 및 교환 메커니즘은 사용자와 서버간의 인증된 마스터키를 통한 사용자와 인증자의 상호인증과, 키 생성과 키 교환하는 방법에 초점을 맞추고 있다. 이러한 키를 생성하기 위한 Pairwise 키 체계와 키 교환을 위한 4-Way Handshake, 4-Way Handshake에서 사용되는 EAPOL-Key message에 대하여 분석하였다.

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Sorption behavior of Eu(III) on Tamusu clay under strong ionic strength: Batch experiments and BSE/EDS analysis

  • Zhang, Han;He, Hanyi;Liu, Jun;Li, Honghui;Zhao, Shuaiwei;Jia, Meilan;Yang, Jijun;Liu, Ning;Yang, Yuanyou;Liao, Jiali
    • Nuclear Engineering and Technology
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    • 제53권1호
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    • pp.164-171
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    • 2021
  • The europium sorption on Tamusu clay was investigated by batch sorption experiments and spectroscopic study under the condition of strong ionic strength. The results demonstrated that europium sorption on Tamusu clay increased rapidly with pH value, but decreased with the ionic strength of solution increased. The europium sorption also increased in the presence of humic acid, especially at low pH value. The sorption could be fitted by Freundlich isotherm model and the europium sorption on clay was spontaneous and endothermic reaction. Besides, the result indicates that ion exchange was the main process at low pH value, while inner-sphere surface complexation dominated the sorption process at high pH value. The Backscatter electron scanning/Energy Dispersive Spectrometer(BSE/EDS) and the effect of Na for europium sorption results further suggested that europium sorption on Tamusu clay mainly competed with Na at low pH value. Overall, the results in this research were of significance to understand the sorption behavior of europium on the geological media under high ionic strength.

안전성이 증명 가능한 효율적인 동적 그룹 키 교환 프로토콜 (Provably-Secure and Communication-Efficient Protocol for Dynamic Group Key Exchange)

  • Junghyun Nam;Jinwoo Lee;Sungduk Kim;Seungjoo Kim;Dongho Won
    • 정보보호학회논문지
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    • 제14권4호
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    • pp.163-181
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    • 2004
  • 그룹 키 동의 프로토콜은 일련의 그룹을 형성하는 다수의 통신 참여자들이 공개된 통신망을 통해 안전하고 효율적인 방법으로 그룹의 세션키를 설정하기 위한 목적으로 설계된다. 하지만, 기존에 제안된 그룹 키 동의 프로토콜들은 모두 상당한 양의 통신 부하를 유발하기 때문에 전송 지연이 긴 WAN 환경에는 적합하지 않다. 이러한 네트워크 환경에서는 특히 라운드 복잡도와 메시지 복잡도가 프로토콜의 수행 시간을 결정하는 핵심 요소들로서, 무엇보다 이들을 줄이는 것이 효율적인 그룹 키 동의 프로토콜의 설계를 위해 중요하다고 할 수 있다. 따라서 본 논문에서는 라운드 수와 메시지 수 측면에서 효율적인 그룹 키 동의 프로토콜을 제안하고, 이의 안전성을 소인수 분해 문제에 기반 하여 랜덤 오라클 모델에서 증명한다. 제안된 프로토콜은 완전한 전방향 안전성과 최적의 메시지 복잡도를 제공하면서도 상수 라운드만에 그룹멤버의 변경에 따른 세션키 갱신을 수행한다.

Theorizing Length of Relationship as Moderator of Key Account Management Performance- Repeat Order Link

  • Ahmmed, Kawsar;Mohd, Nor Azila
    • 융합경영연구
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    • 제2권1호
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    • pp.1-17
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    • 2014
  • In today's highly competitive and fast changing business environment, key account management-a supplier company initiated relationship marketing approach targeted at the most important customers to solve their complex requirements with special treatment that eventually ensures both parties' financial and nonfinancial objectives- has regarded as a strategic weapon of many companies' sales efforts to manage their strategically important customers. On the basis of the existing studies, this research introduces a theoretical model highlighting the hypothetical relationship between key account management performance and repeat order. In addition, moderating effect of length of relationship on the relationship between key account management performance and repeat order is also introduced. We theorize the conditions under which key account management performance influences key customer repeat order behavior as well as the influence of moderating variable of length of relationship on key account management performance-repeat order relationship. Theoretical and managerial implications are provided along with suggestions to isolate a platform for future empirical research.

Removal of different anionic dyes from aqueous solution by anion exchange membrane

  • Khan, Muhammad Ali;Khan, Muhammad Imran;Zafar, Shagufta
    • Membrane and Water Treatment
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    • 제8권3호
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    • pp.259-277
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    • 2017
  • Adsorption is a widely used technique for the removal of dyes from wastewaters by variety of adsorbents. In this work, the main focus is on the potential assessment of anion exchange membrane for the removal of different dyes using batch system and investigation of experimental data by applying various kinetic and thermodynamic models. The removal of anionic dyes i.e., Eosin-B, Eriochrome Black-T and Congo Red by anion exchange membrane BII from aqueous solution was carried out and effect of various parameters such as contact time, membrane dosage, temperature and ionic strength on the percentage removal of anionic dyes was studied. The experimental data was assessed by kinetic models namely pseudo-first-order, pseudo-second-order, Elovich liquid film diffusion, Bangham and the modified Freundlich models equation have been used to analyze the experimental data. These results indicate that the adsorption of these anionic dyes on BII follows pseudo-second-order kinetics with maximum values of regression coefficient (0.992-0.998) for all the systems. The adsorption of dyes was more suitable to be controlled by a liquid film diffusion mechanism. The adsorptive removal of dye Eosin-B and Eriochrome Black-T were decreased with temperature and thermodynamic parameters such as free energy (${\Delta}G^o$), enthalpy (${\Delta}H^o$) and entropy (${\Delta}S^o$) for adsorption of dyes on membrane BII were calculated at 298 K, 308 K and 318 K. The values of enthalpy and entropy were negative for EB and EBT representing that the adsorption of these dyes on BII is physiosorptive and exothermic in nature. Whereas the positive values of enthalpy and entropy for CR adsorption on BII, indicating that its adsorption is endothermic and spontaneous in nature. It is evident from this study that anion exchange membrane has shown good potential for the removal of dyes from aqueous solution and it can be used as adsorbent for dues removal on commercial levels.

Acid green-25 removal from wastewater by anion exchange membrane: Adsorption kinetic and thermodynamic studies

  • Khan, Muhammad Imran;Ansari, Tariq Mahmood;Zafar, Shagufta;Buzdar, Abdul Rehman;Khan, Muhammad Ali;Mumtaz, Fatima;Prapamonthon, Prasert;Akhtar, Mehwish
    • Membrane and Water Treatment
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    • 제9권2호
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    • pp.79-85
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    • 2018
  • In this work, batch adsorption of anionic dye acid green-25 (AG-25) from aqueous solution has been carried out at room temperature using anion exchange membrane (DF-120B) as a noval adsorbent. The effect of various experimental parameters such as contact time, membrane dosage, ionic strength and temperature on the adsorption of dye were investigated. Kinetic models namely pseudo-first-order, pseudo-second-order, Elovich, liquid film diffusion, Bangham and modified freundlich models were employed to evaluate the experimental data. Parameters like adsorption capacities, rate constant and related correlation coefficients for every model are calculated and discussed. It showed that adsorption of AG-25 onto DF-120B followed pseudo-first-order rate expression. Thermodynamic study indicates that adsorption of AG-25 onto DF-120B is an exothermic and spontaneous process.

The Authenticity of Business to Business Salespersons on Consultative Selling Competence: The Role of Customer Orientation

  • Jin-Hwan Lim;Min-Jae Park
    • 아태비즈니스연구
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    • 제14권4호
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    • pp.1-21
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    • 2023
  • Purpose - The study investigates the role of authenticity of B2B salespersons has on their consultative selling competence. The study also examines the mediating effect of customer orientation between the authenticity of B2B salespersons and their consultative selling competence, as well as the moderating role of trust in the buyer-seller exchange. Design/methodology/approach - This research utilized a covariance-based structural equation model technique. The study assessed the research model's moderation effects through a stepwise approach, which allowed for an examination of the moderating effect of trust in the buyer-seller relationship. Findings - As a result of structural equation analysis, this study found that the authenticity of B2B salespersons influences their consultative selling competence by mediating their customer orientation significantly. In addition, trust in the buyer-seller exchange plays a significant role as a moderating variable between customer orientation and competitive selling competence, but it is not significant as a moderating variable between the authenticity and customer orientation of B2B salespersons. Research implications or Originality - This research proposed the role of authenticity of the B2B salesperson as a key factor in the trust-based relationship and a key variable of consultative selling competence. The study has taken the research on the authenticity of the B2B salesperson one step further from the study of authenticity of the brand and the company's leadership.