• Journal of Communications and Networks
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• v.7 no.4
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• pp.525-536
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• 2005

In an IP-based network, automated dynamic assignment of IP addresses is preferable. In most wired networks, a node relies on a centralized server by using dynamic host configuration protocol (DHCP) to obtain a dynamic IP address. However, the DHCP­based approach cannot be employed in a mobile ad hoc network (MANET) due to the uncertainty of any centralized DHCP server. That is, a MANET may become partitioned due to host mobility. Therefore, there is no guarantee to access a DHCP server. A general approach to address this issue is to allow a mobile host to pick a tentative address randomly, and then use duplicate address resolution (DAR) protocol to resolve any duplicate addresses. In this paper, an innovative distributed dynamic host configuration protocol designed to configure nodes in MANET is presented. The proposed protocol not only can detect the duplicate address, but also can resolve the problem caused by duplicate address. It shows that the proposed protocol works correctly and is more universal than earlier approaches. An enhanced version of DAR scheme is also proposed in this paper to solve the situation of duplicate MAC address. The new and innovative approach proposed in this paper can make the nodes in MANET provide services to other networks and avoid packets from being delivered to incorrect destinations.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.709-719
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• 1996

DHCP(Dynamic Host Configuration Protocol)is a protocol which dynamically allocates an IP address and/or host configuration parameters to a host. But because this protocol uses broadcasting for message exchange, it causes heavy traffic and overload on the network. By avoiding unnecessary broadcasting and using a simple and efficient implementation model, we can reduce such heavy traffic and overload. We have studied on characteristics of the broadcasting the traffic caused by DHCP, and implement the model which can reduce traffic by improving algorithm and unicasting messages.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.4
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• pp.747-754
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• 2016

DHCP(Dynamic Host Configuration Protocol) is a protocol for efficiency and convenience of the IP address management. DHCP automatically assigns an IP address and configuration information needed to run the TCP/IP communication to individual host in the network. However, existing DHCP is vulnerable for network attack such as DHCP spoofing, release attack because there is no mutual authentication systems between server and client. To solve this problem, we have designed a new DHCP protocol supporting the following features: First, ECDH(Elliptic Curve Diffie-Hellman) is used to create session key and ECDSA(Elliptic Curve Digital Signature Algorithm) is used for mutual authentication between server and client. Also this protocol ensures integrity of message by adding a HMAC(Hash-based Message Authentication Code) on the message. And replay attacks can be prevented by using a Nonce. As a result, The receiver can prevent the network attack by discarding the received message from unauthorized host.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.544-548
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• 2004

DHCP(Dynamic Host Configuration Protocol) is a protocol which dynamically allocates an IP address and/or host configuration parameters to a host. The DHCP client's address can be changed dynamically any time. For the possible communication with other system, the DHCP client has to inform its address to the DNS system with dynamic update facility. But the DNS dynamic update has a problem related to the security. So we proposed the efficient mechanism for the secure integration of DHCP and DNS by using DNS security extensions. The system also uses the DNS server as the certificate repository for the storing & retrieval of each other's certificate.

• The KIPS Transactions:PartC
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• v.16C no.6
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• pp.753-760
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• 2009

As it becomes increasingly important that Internet access is available anywhere at any time, providing MANET (Mobile Ad-Hoc Network) with the Internet access attracts more attention. The existing DHCP (Dynamic Host Configuration Protocol) address configuration schemes require message exchanges between MANET nodes and the DHCP server through multi-hop routes. Messages can be easily dropped in the wireless multi-hop communication environment and the address configuration may be instable and need long delay. In this paper, we propose a new address configuration scheme using the concept of address pool allocation. In the proposed scheme, the DHCP server assigns a part of its address pool to a node instead of a single address and the node can assign a part of its own address pool to its neighbor nodes. Through simulation studies, we show that our scheme yields about 77% of the address configuration delay and 61% of the control message overhead of the existing DHCP based mechanism.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.837-840
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• 2005

본 논문은 DHCP(Dynamic Host Configuration Protocol) 메시지 인증에 관한 것으로 홈네트워크에서 적용 가능한 디바이스 인증 및 사용자 인증과의 관련성에 대해 살펴본다. 또한, 본 논문에서 제안하는 DHCP 메시지 인증은 DHCP 서버가 IP 주소 할당을 요구하는 DHCP 클라이언트들에게 IP 주소를 할당함에 있어서, 인증 과정을 거친 후 인증에 성공한 클라이언트에게만 IP 주소를 할당 해주고, DHCP 클라이언트도 자신이 등록된 DHCP 서버로부터만 IP 주소를 할당 받을 수 있는 DHCP 메시지 인증 방법을 제안함에 있어서 효과적이고 보안성을 강화한 키관리 방법으로 리플레이 공격에 대한 방지법을 포함하는 DHCP 메시지 인증 방법을 제공한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.640-642
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• 2015

DHCP(Dynamic Host Configuration Protocol)는 TCP/IP 통신을 실행하기 위해 필요한 IP 주소 및 관련된 세부 구성 정보를 자동적으로 할당한다. 기존의 DHCP는 서버와 클라이언트 간 상호 인증 체계가 없어서 다양한 네트워크 공격에 취약하다. 본 논문에서는 기존 DHCP 메시지 옵션에 네트워크 공격을 방지할 수 있도록 지원하는 옵션을 추가하였다. DHCP 통신 과정에서 ECDSA와 HMAC 알고리즘 등을 이용하여 메시지의 무결성을 보장하고 서버와 클라이언트 간 상호 인증을 수행한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2300-2305
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• 2009

Recently, Telecommunication companies have introduced a new network architecture that assigns network resources consistent and protects their systems more secure. Now, they provide multimedia services through various types of access networks. In this study, I'd like to introduce IP address assignment method based on the Dynamic Host Configuration Protocol (DHCP) and find out how success or failure of Ip address assignment will be taken place according to the booting order of xDSL modem, AP and PC.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.793-795
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• 2001

Ad-hoc 망은 인터넷과는 다른 독립적인 망을 구성하는 경우 사용되게 된다. 이러한 Ad-hoc의 특정 호스트가 인터넷 망과의 연결을 시도하는 경우, 이 호스트로의 패킷의 라우팅을 위해서는 모든 경로상의 라우터에서 이 호스트에 대한 정보의 엔트리가 추가되어야만 한다. 이는 망 구현 과정에서 확장성 (Scalability) 문제를 야기하게 된다. 즉, 라우팅 테이블 엔트리의 증가로 차지하는 라우터의 메모리 문제나, 해당 호스트의 정보를 찾고자 할 때의 소요시간으로 적용하기 어렵다. 이러한 확장성 문제를 제거하는 방법으로 자동으로 주소를 설정 하는 방식인 DHCP(Dynamic Host Configuration Protocol)에 대해서 알아 보았다. 그리고. DHCP의 문제점인 기존의 라우팅 정보를 손실되는 문제가 있어 적용하기 어렵다. 이에 본 논문은 확장성 문제를 제거하는 동시에 엑세스 포인트(access point)에서 NAT(Network Address Translation) 기술을 적용하여 AODV(Ad-Hoc On-Demand Distance Vector) 라우팅 프로토롤과 인터넷의 연동을 위한 메커니즘을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1203-1206
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• 2008

VoIP 서비스에서 긴급통화 서비스는 사용자 단말의 위치 정보(Location Information)와 사용자 식별번호를 긴급 호에 실어 긴급 대응 센터에 보내는 서비스이다. VoIP 긴급통화 서비스를 위하여 긴급 호발생 시 위치를 획득하여야 하며, 이를 위해 본 논문에서는 RFC 4776기반의 DHCP 옵션 확장하여 VoIP 단말의 위치 정보를 획득하는 방법을 구현하였다.