• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.143-146
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• 2005

본 논문에서는 동영상 데이터 암호화를 위해 비디오 데이터의 I-프레임 암호화 기법을 제안한다. 또한 시스템 서버에서 암호화된 멀티미디어 데이터를 클라이언트 시스템에서 사용자가 실행할 때 자동으로 사용자 인증과 데이터의 복호화를 수행할 수 있도록 하는 라이선스 에이전트를 제안한다. 라이선스 에이전트는 사용자의 멀티미디어 데이터의 실행 시 공유 키 풀(shared key pool)을 이용한 PKI(Public Key Infrastructure)기반의 사용자의 인증과 멀티미디어 데이터의 암호 및 복호화를 수행한다. 또한 비밀키 기반의 공개키 분배 시스템을 이용하여 키의 누출을 미연에 방지하고 키의 누출 시 그 경로를 추적할 수 있도록 하였다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.3
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• pp.119-128
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• 2002

In case certification between user and service provider is achieved, problem that user's identity is revealed is occurring by social issue, so it was presented identity escrow scheme to solve these problem. In identity escrow scheme, the issuer who have correct user's identity transmits securely anonymity authentication information to user, and user achieves authentication phase with service provider keeping oneself anonymity using this. In this paper, we present requirement for security and trusty of identity escrow scheme and propose new mechanism that can security this. Also, propose method that service provider can deliver securely contents to user and propose mechanism that improve that support ky recovery at encryption communication that using secret key that it was generated by key agreement between users.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.616-619
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• 2008

In this paper, we design and implement the authentication system for home network service and applied it to actual sensor nodes. We achieved authentication key, encryption and decryption applied RC5 encryption algorithm of SNEP. In addition, we used pair-wise key pre-distribution for prevention of authentication sniffing in wireless sensor network. The experiment environment consists of a base station receiving data and sensor nodes sending data. Each sensor nodes sends both the data and encrypted authentication key to the base station. As a simulation environment, we assumed some what-if scenarios of security menaces in home network service. And we slightly altered the TOS_Msg construction of TinyOS. The experiences had shown that the malfunction doesn't happen in communication among other groups. And we confirmed in tests that the system is secure when a sensor having malicious propose is added.

• Proceedings of the Korean Information Science Society Conference
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• 2010.11a
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• pp.82-83
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• 2010

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.1202-1205
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• 2007

최근 무선랜의 이용이 급격하게 증가하고 있는 추세이다. 무선랜은 이동통신에 비해 빠른 데이터 전송이 가능하여 화상통신, VoIP, 동영상 스트리밍 등 멀티미디어 서비스에 적합하다. 하지만 무선랜은 서비스 제공 영역이 작기 때문에 사용자가 자주 이동할 경우 핸드오프가 발생하여 딜레이가 증가한다. 딜레이에 민감한 멀티미디어의 경우 서비스 품질에 영향을 받을 수 있으므로 이에 대한 고려가 필요하다. 본 논문에서는 핸드오프의 인증 과정에서 발생하는 딜레이를 줄이기 위해 핸드오프 할 때 사용되는 임시 키인 THK 의 사용을 제안한다. THK 를 이용할 경우 인증 서버를 이용하지 않고도 인증이 가능하며 사용하는 메시지의 양도 작기 때문에 딜레이 감소가 가능하다. 시뮬레이션 결과는 우리가 제안한 프로토콜을 이용할 경우 현재 사용 중인 프로토콜에 비해 최고 2 배의 성능 향상을 얻을 수 있음을 보여준다.

• Journal of Internet Computing and Services
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• v.9 no.2
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• pp.61-68
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• 2008

Authentication for inter-NEMO rooming is on important issue for achieving the seamless mobile networking. In this proposal, the technical challenge lies in the fact that a visited network does not initially have the authentication credentials of a roaming mobile router. This paper proposes an efficient approach for providing AAA service in NEMO environment. This approach uses localized authentication based on the roaming agreement between ISPs. A public key certificate structure is proposed, tailored to the business model of wireless internet Service Providers (ISPs). In this approach, the mutual authentication between a visited network and a roaming user can be performed locally without any control with user's home network. In conclusion, our protocol shown that communication delay can be reduced by overuse 45% overhead in communication delay than the previous AAA approach.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2C
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• pp.348-353
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• 2004

Development of an efficient and secure payment system is prerequisite for the construction of electronic payment mechanism in mobile environment. Since current PayWord protocol system generates vendor's certificate for each transaction, it requires lot of operation for transaction. In this paper, we use a session key generated by ID-based tripartite Key agreement protocol which use an Elliptic Curve Cryptosystem over finite field $F_{q}$ for transactions. Therefore, our protocol reduces algorithm operations. In particular, proposed protocol using ID-based public key cryptosystem has the advantages over the existing systems in speed and it is more secure in Man-in-the-middle attacks and Forward secrecy.

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.317-322
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• 2005

The existing certificate based authentication or identification just verifies whether the owner of private key corresponding to public key of certificate is the DN user set in the user field in the certificate or not, then we cannot find out who is the actual private key owner in a real world. To make up for this weak points, the method to insert the identification number like the resident registration number into the certificate extension field is applied as a technical standard to current domestic PKI system. In this paper, we propose the ECC based integrated identification, identification number checking and key management protocol providing user validation during the login.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.75-86
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• 2014

Demand for the femtocell is largely credited to the surge in a more always best connected communication conscious public. 3GPP defines new architecture and security requirement for Release 9 to deal with femtocell, Home eNode B referred as HeNB. In this paper, we analyze the HeNB security with respect to mutual authentication, access control, and secure key agreement. Our analysis pointed out that a number of security vulnerabilities have still not been addressed and solved by 3GPP technical specification. These include eavesdropping, man-in-the-middle attack, compromising subscriber access list, and masquerading as valid HeNB. To the best of our knowledge, any related research studying HeNB security was not published before. Towards this end, this paper proposes an improved authentication and key agreement mechanism for HeNB which adopts proxy-signature and proxy-signed proxy-signature. Through our elaborate analysis, we conclude that the proposed not only prevents the various security threats but also accomplishes minimum distance from use-tolerable authentication delay.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1519-1523
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• 2007

In this paper, we propose the fast and secure binding update protocol as handoff or handover in the micro and pico environment based on mobile IPv6. The nodes or routers on participating in this protocol generate their addresses from cryptographically generated addresses (CGAs) method unlike previous address generation method. The mobile node (MN) includes in home network or home link has limited power and computational abilities. So the home agent (HA) of the MN executes key agreement protocol with the correspondent node (CN) on behalf of the MN. The CN then creates a ticket on including session key, lifetime of ticket. and so on. It then transmits it to the MN via the HA of the MN. The ticket is used to communicate directly between the MN and its CN. In performance analysis, we analyze security of proposed binding update protocol under various attack scenarios and efficiency by comparing proposed protocol with prior binding update protocols. Finally we make a conclusion of this paper and present future works.