• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.6
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• pp.135-149
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• 2006

Securing wireless Ad hoc network including the secure mechanism design and implementation is generally more difficult for vulnerability of channels and nodes, the absence of infrastructure, topology that change dynamically, and etc, than ire network. The efforts of early researches are based on the adaptation of securing methods for the wire network to wireless ad hoc network. However, wireless ad hoc network could not get effective study finding because network has essential problems. This paper proposes that some new problems are being came to light over the survivability and availability of the network itself, that are caused by the massive packet attack of more than one or two nodes, and proves the consequence of this phenomenon. Also, we propose an effective prevention mechanism of masquerade attacks for survivability reinforcement that escape standard of the early way by survivability of wireless Ad hoc network and approaches for performance elevation and reflect special quality of wireless Ad hoc network.

• Journal of Korea Multimedia Society
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• v.8 no.7
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• pp.974-987
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• 2005

As the ad hoc networks have been received a great deal of attention to not only the military but also the industry applications, some security mechanisms are required for implementing a practical ad hoc application. In this paper, we propose a security architecture in ad hoc networks for the purpose of supporting ID-based public key cryptosystems because of the advantage that ID-based schemes require less complex infrastructure compared with the traditional public key cryptosystems. We assume a trusted key generation center which only issues a private key derived from IDs of every nodes in the system setup phase, and use NIL(Node ID List) and NRL(Node Revocation List) in order to distribute the information about IDs used as public keys in our system. Furthermore, we propose a collaborative status checking mechanism that is performed by nodes themselves not by a central server in ad-hoc network to check the validity of the IDs.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1654-1662
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• 2006

An ad hoc network is multi-hop network composed of radio links. and the transmission quality of a radio link is more unstable than that of a wired circuit. Packet loss thus occurs frequently in an ad hoc network, and the consequent connection failure results in a severe deterioration of TCP performance. TCP performance also deteriorates because of the collision of data packets and ACK packets in the radio channel. In this paper we study to improve the performance of the Mobile Ad-hoc network by using Delayed ACK algorithm with our proposed ODA(Ordering-Delayed ACK) method. The proposed ODA algorithm increases the number of the data packets orderly at the receiver side which is going to be applied for the Mobile Ad-hoc network. We accomplished a computer simulation using NS-2. From the simulation results, we find the proposed ODA algorithm obviously enlarge the channel capacity and improve the network performance at the situation of multi-hop of ad-hoc network than the existing Delayed ACK algorithm.

• Journal of KIISE:Information Networking
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• v.33 no.4
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• pp.310-323
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• 2006

In this paper, we describe a secure cluster-routing protocol based on a multi-layer scheme in ad hoc networks. We propose efficient protocols, Authentication based on Multi-layer Clustering for Ad hoc Networks (AMCAN), for detailed security threats against ad hoc routing protocols using the selection of the cluster head (CH) and control cluster head (CCH) using a modification of cluster-based routing ARCH and DMAC. This protocol provides scalability of Shadow Key using threshold authentication scheme in ad hoc networks. The proposed protocol comprises an end-to-end authentication protocol that relies on mutual trust between nodes in other clusters. This scheme takes advantage of Shadow Key using threshold authentication key configuration in large ad hoc networks. In experiments, we show security threats against multilayer routing scheme, thereby successfully including, establishment of secure channels, the detection of reply attacks, mutual end-to-end authentication, prevention of node identity fabrication, and the secure distribution of provisional session keys using threshold key configuration.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4A
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• pp.309-315
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• 2009

Wireless Ad-hoc networks are dynamic networks that consist of mobile nodes. Nodes in Ad-hoc networks are usually laptops, PDAs or mobile phones. These devices feature Bluetooth and/or IEEE 802.11 (WiFi) network interfaces and communicate in a decentralized manner. Due to characteristics of Ad-hoc networks, Mobility is a key feature of routing protocol design. In this paper, we present an enhanced routing maintenance scheme that cope with topology changes pre-actively. The key feature of the proposed scheme is to switch next-hop node to alternative neighbor node before link breakage for preventing route failure. From extensive experiments by using NS2, the performance of the proposed scheme has been improved by comparison to AODV protocol.

• Journal of Internet Computing and Services
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• v.2 no.3
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• pp.9-17
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• 2001

Ad-Hoc networks consist of a set of mobile hosts that communicate using wireless links, without the use of other communicate support facilities (such as base stations). The topology of an Ad-Hoc network changes due to the movement of mobile host. which may lead to sudden packet loss. Recently, a large amount of research has focused on the routing protocols needed in such an environment. but researches about Internet traffic performance analysis were unexhausted. Accordingly, we have simulated Ad-Hoc mobile network that using AODV routing protocol and Ad-Hoc mobile network topology size and node speed as simulation estimation-factor to analysis traffic performance. As the result of the simulation, we identify that TCP /Reno was more sensitive than TCP/Sack about node speed and a number of the node.

• Journal of Satellite, Information and Communications
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• v.9 no.4
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• pp.20-25
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• 2014

In this paper, we provide efficient spectrum sensing technology for smooth use of frequency and energy charge of multi-copter. The proposed structures focus on improving performance of spectrum sensing that is based on Ad-hoc network. First, we explain basic principles and disadvantages of cooperative spectrum sensing and ad-hoc based spectrum sensing. To solve these problems, in this paper, we employ the beamforming technology that guarantees higher transmit primary users' signal power to secondary users in ad-hoc network. The performance of proposed algorithm is analyzed in terms of detection probabilities, and the results of this paper can be applied to the various ad-hoc based Cognitive Radio system.

• Review of KIISC
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• v.20 no.4
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• pp.85-94
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• 2010

Ad-hoc 네트워크는 노드가 자유롭게 이동하면서 네트워크를 구성하며, 어떠한 고정된 AP(Access Point)의 도움 없이 자신들의 연결만을 통해 통신망을 제공한다. Ad-hoc 네트워크에서는 기존 인터넷 망에서 존재하는 공격이 가능하다. 이런 공격에 대응하기 위하여 기존 유선망에서의 IP기반 역추적 기술을 바탕으로 ad-hoc 네트워크에서의 역추적 연구가 이루어지고 있다. 본 논문에서는 ad-hoc 네트워크 및 기존 유선망에서의 IP기반 역추적 기술들에 대하여 알아 본 후, 최근 발표된 ad-hoc 네트워크기반의 역추적 대표적인 기술들의 기법들에 대해 살펴본다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.571-573
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• 2003

Ad­Hoc 네트워크에서는 노드의 위상 변화가 빈번히 발생하므로 경로 탐색 및 관리가 중요하다. 그러나 자원의 사용이 제한된 무선망에서 경로 탐색과 관리에 많은 자원을 소비하게 되면, 데이터 처리시의 자원사용에 영향을 미치게되므로 네트워크의 효율이 저하된다. 효율적인 Ad­hoc 네트워크를 구성하기 위해서는 효율적인 라우팅 프로토콜의 설계가 매우 중요하다. 현재 표준으로 제정된 Ad­Hoc 라우팅 프로토콜들과 그 개선방안에 대해 살펴보고, 보안에 취약한 Ad­Hoc 네트워크에서 보안성을 제공하기 위해 제안된 프로토콜에 관해 살펴본다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.1
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• pp.58-64
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• 2005

The nodes of Ad-hoc network are made up of location registration for sending information and a great number of packet transmissions to maintain routing route among the nodes. under this environment, a huge number of traffics would be generated as mobility variable occurs more than in physical network. Hence, in this paper, focused on to study the relationship of nodes to analyze the extend of the traffic in order to control the traffics of the multi-hop in Ad-hoc.