• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2006.07a
• /
• pp.682-682
• /
• 2006

• Proceedings of the KIEE Conference
• /
• 2007.10a
• /
• pp.211-212
• /
• 2007

최근 자가 구성이 가능한 모바일 애드 혹 네트워크상에서 통신을 지원하기 위하여 DSR, AODV등 많은 On Demand 라우팅 프로토콜들이 제안되었다. 이들 라우팅 프로토콜들은 경로탐색과정에서 Route Request(RREQ) 패킷을 브로드캐스트하여 목적 노드로부터 Route Reply(RREP) 패킷을 받음으로써 라우팅 경로를 설정한다. 이때 경로탐색의 지연을 최소로 줄이고자 과거 경로탐색 정보 및 라우팅 정보를 경로캐쉬에 저장하여, 중간노드에서 RREP를 대신 보낼 수 있다. 이러한 캐쉬 기법은 간단하면서 매우 효율적인 방법이지만, 캐쉬 정보가 잘못된 경우 불필요한 지연을 일으킨다. 더욱이 캐쉬 정보를 이용할 경우, 특정 노드에게 보내는 데이터가 집중되는 문제가 발생하여 혼잡의 원인이 된다. 본 논문에서는 이러한 혼잡을 해결하고자 캐쉬 정보를 동적으로 관리하여, 혼잡의 원인이 되는 RREP를 억제하고자 한다. 이를 위하여 혼잡 임계값 및 파라미터를 정의한다. 마지막으로 실험을 통하여 네트워크 트래픽이 많을 경우 제안된 기법을 적용했을 때, 더 우수한 성능을 가짐을 보인다.

• Journal of the Korea Society of Computer and Information
• /
• v.17 no.11
• /
• pp.73-81
• /
• 2012

This paper proposes an ETWAD(Encapsulation and Tunneling Wormhole Attack Detection) design based on positional information and hop count on Ad-Hoc Network. The ETWAD technique is designed for generating GAK(Group Authentication Key) to ascertain the node ID and group key within Ad-hoc Network and authenticating a member of Ad-hoc Network by appending it to RREQ and RREP. In addition, A GeoWAD algorithm detecting Encapsulation and Tunneling Wormhole Attack by using a hop count about the number of Hops within RREP message and a critical value about the distance between a source node S and a destination node D is also presented in ETWAD technique. Therefore, as this paper is estimated as the average probability of Wormhole Attack detection 91%and average FPR 4.4%, it improves the reliability and probability of Wormhole Attack Detection.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.6
• /
• pp.1011-1016
• /
• 2020

Rapid change in network topology in high-speed VANET(: Vehicular Ad Hoc Network) is an important task for routing protocol design. Selecting the next hop relay node that affects the performance of the routing protocol is a difficult process. The disadvantages of AODV(: Ad Hoc On-Demand Distance Vector) related to VANET are end-to-end delay and packet loss. This paper proposes the AAODV (Advanced AODV) technique to reduce the number of RREQ (: Route Request) and RREP (: Route Reply) messages by modifying the AODV routing protocol and adding direction parameters and 2-step filtering. It can be seen that the proposed AAODV reduces packet loss and minimizes the effect of direction parameters, thereby increasing packet delivery rate and reducing end-to-end delay.

• Journal of Korea Multimedia Society
• /
• v.11 no.10
• /
• pp.1409-1419
• /
• 2008

Inauthentic resources can be easily spread by P2P (Peer-to-Peer) participants due to the openness and anonymity of P2P networks. A possible way to restrict the distribution of inauthentic resources and prevent malicious peers from joining P2P networks is to exploit peers' reputation which reflect their past behaviors and are also helpful to predict peers' future behaviors. There is a possibility that some peers intentionally plays along with other peers in order to increase/decrease its reputation through false feedback exchanges. Therefore, we propose a new reputation management scheme, called TrustRRep (Trustable Resource sharing service using Reputation) scheme, which improves the trustworthiness and efficiency of P2P networks by identifying peers who give false feedback. The TrustRRep scheme is also capable of providing peers with the trustworthiness of shared resources by discriminating resources distributed by malicious peers. We implement the proposed TrustRRep scheme on the NS-2 simulator for evaluating its performance compared to the recent reputation management work available in literature. A case study on simulations shows that the proposed reputation management scheme yields efficient performance in terms of the minimal download ratio and dissemination of inauthentic resources, the efficient identification of peers who give false feedback, and the provisioning of the trustworthiness of peers' reputation. It also shows that the proposed TrustRRep scheme imposes the restrictions of participating P2P networks on a malicious peers by diminishing its trust value.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
• /
• v.3 no.1
• /
• pp.15-24
• /
• 2004

'The delay and control overhead during route discovery for destinations outside ad hoc networks are major obstacle to achieving scalability in the Internet. To solve this issue, we propose a novel route discovery scheme equipped with two augmented functions. In this paper, the Internet gateway maintains an address cache of Internet nodes frequently accessed from the ad hoc network and replies with an extended Route Response (RREP) message to the Route Request (RREQ) message based on its routing table and the address cache called EXIT(EXternal node Information Table). These augmented functions make the source node determine the location of the destination as fast as possible. Through simulations, the proposed route discovery scheme using both EXIT and extended RREP message shows considerable' reduction in both route discovery time and control message overhead.

• The KIPS Transactions:PartC
• /
• v.13C no.4 s.107
• /
• pp.447-454
• /
• 2006

An ad-hoc network routing protocol, AODV(Ad-hoc On-demand Distance Vector) initially uses ERS(Expanding Ring Search) algorithm to control the RREQ(Route Request) retransmission in the route discovery process. Because ERS uses the fixed NTT(Node Travesal Time), it does not reflect accurately ad-hoc network environment. In this paper, we propose an improved ERS algorithm which lowers the retransmission rate. It uses RREP(Route Reply) and gives different weights in NTT of each node in accordance with the adjacency to an originating node. To show the effectiveness of the proposed algorithm, we perform a simulation using ns2. The simulation results showed that the proposed algorithm has better performance than existing algorithms.

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.11a
• /
• pp.61-63
• /
• 2005

본 논문에서는 무선 애드 혹 네트워크상의 패킷 폐기 공격의 영향을 분석하고 시뮬레이션을 통해 그 효과를 측정하였다. 시뮬레이션 수행 결과 RREQ 패킷을 폐기한 경우에는 네트워크에 미치는 영향이 적은 반면, RREP 및 DATA 패킷을 폐기한 경우는 네트워크의 전송 효율이 떨어졌으며. 또한 패킷을 폐기하는 악성노드가 많을수록 데이터의 전달율이 감소하고 하나의 데이터를 전송 하는데 필요한 제어 패킷의 수가 늘어남을 알 수 있었다. 시뮬레이션을 통해 분석된 결과를 바탕으로 패킷 폐기 공격의 징후를 미리 검출하거나 공격 형태를 식별하는 기초 자료로 활용가능 할 것이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.216-219
• /
• 2012

In wireless ad-hoc networks, the nodes configuring a path act as routers with various mobility. If the path is broken by the movement of a node, a new path have to be found again. For this reason, the node with high mobility should be excluded from structuring a path as far as possible. In this paper, we propose an algorithm which excludes nodes with high mobility from constructing a path by collecting and managing the information of mobility. As the result, this can provide more stable paths. The proposed algorithm uses the extended AOMDV method. In this algorithm, we appends History Field and Decline Field in the routing table to collect and manage the mobility information. In addition, we add Mbl Field to RREP (Route Reply) message to apply the collected information to configure the real path.

• Journal of KIISE:Information Networking
• /
• v.35 no.6
• /
• pp.529-537
• /
• 2008

AODV routing protocol is intended for use by mobile' nodes in an ad-hoc network. In AODV nodes create routes on an on-demand basis. As the degree of node mobility becomes high, however, the number of the control packets, RREQ and RREP messages, have increased so rapidly. The unexpected increases in the number of the control packets cause the destination node to decrease the packet receiving rate and also to increase the overall energy consumption of such a network. In this paper, we propose a novel method of adaptively controlling the occurrences of such RREQ messages based on AIAD (additive increase additive decrease) under a consideration of the current network status. We have tested our proposed method with the conventional AODV and the method using timestamp based on the three performance metrics, i.e.. how long does node moves, node velocity, and node density, to compare their performance.