• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.121-124
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• 2001

Dynamic Source Route(DSR) protocol is a simple and efficient routing protocol designed specially for use of the multi-hop Ad Hoc Network. DSR allows the network to be completely self-organized and self-configured without the need for any existing infrastructure or administration. DSR protocol consists of the two mechanisms of Router discovery and Router Maintenance, works entirely On-demand in all aspects. In this paper, we will present the performance of DSR protocol on the multi-hop wireless Ad Hoc Networks, illustrate it with simulation, and then analysis the algorism of DSR.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.10
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• pp.499-506
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• 2005

The growth of networks increase the importance of electronic commerces. Since the fair exchange protocol is an important part of electronic commerces, a number of researches have been done in relation to the fair exchange protocol. As the contract signing protocol is a part of fair exchange protocol, many protocols have been proposed, but most of them were focused on two-party protocol. Only a few were on the multi-party contract signing protocol. So far the optimistic multi-party contract signing protocol presented by Baum-Waidner has the least number of rounds in asynchronous network[4]. But, the lower bound on the number of rounds required by any optimistic multi-party contract signing protocol has been not known. In this paper, we present a tight lower bound on the number of rounds for optimistic multi-party contract signing protocol.

• Journal of Communications and Networks
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• v.18 no.1
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• pp.75-83
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• 2016

In this paper, we propose a multi-channel medium access control (MAC) protocol, named underwater multi-channel MAC protocol (UMMAC), for underwater acoustic networks (UANs). UMMAC is a split phase and reservation based multi-channel MAC protocol which enables hosts to utilize multiple channels via a channel allocation and power control algorithm (CAPC). In UMMAC, channel information of neighboring nodes is gathered via exchange of control packets. With such information, UMMAC allows for as many parallel transmissions as possible while avoiding using extra time slot for channel negotiation. By running CAPC algorithm, which aims at maximizing the network's capacity, users can allocate their transmission power and channels in a distributed way. The advantages of the proposed protocol are threefold: 1) Only one transceiver is needed for each node; 2) based on CAPC, hosts are coordinated to negotiate the channels and control power in a distributed way; 3) comparing with existing RTS/CTS MAC protocols, UMMAC do not introduce new overhead for channel negotiation. Simulation results show that UMMAC outperforms Slotted floor acquisition multiple access (FAMA) and multi-channel MAC (MMAC) in terms of network goodput (50% and 17% respectively in a certain scenario). Furthermore, UMMAC can lower the end-to-end delay and achieves a lower energy consumption compared to Slotted FAMA and MMAC.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.3371-3396
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• 2016

Authentication protocols for multi-server architectures have gained momentum in recent times due to advancements in computing technologies and associated constraints. Lu et al. recently proposed a biometrics and smartcards-based authentication scheme for multi-server environment. The careful analysis of this paper demonstrates Lu et al.'s protocol is susceptible to user impersonation attacks and comprises insufficient data. In addition, this paper proposes an improved authentication with key-agreement protocol for multi-server architecture based on biometrics and smartcards. The formal security of the proposed protocol is verified using the widely accepted AVISPA (Automated Validation of Internet Security Protocols and Applications) tool to ensure that our protocol can withstand active and passive attacks. The formal and informal security analysis, and performance analysis sections determines that our protocol is robust and efficient compared to Lu et al.'s protocol and existing similar protocols.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.4
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• pp.707-713
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• 2007

This paper implements a RFID multi-band multi-protocol reader platform, possible to select one of the UHF bands used in particular for distribution system in RFID, that is, from 860MHz to 960MHz, through programmable configuration. It also enables implemented platform in this paper to recognize many kinds of TAG protocol, such as EPC Class 1 GEN 1, Class 1 Gen2, ISO 18000-6A, B and C.

• The KIPS Transactions:PartC
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• v.12C no.1 s.97
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• pp.111-120
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• 2005

A mobile ad-hoc network is an autonomous system of mobile nodes which are free to move around randomly and organize themselves arbitrarily, hence a routing protocol that handles the dynamic network topology changes is required for the network. In this paper we present a multi -Path on-demand routing protocol called R-DSR (Robust Dynamic Source Routing), an extension to the existing IETF protocol DSR. The proposed protocol has it that every pair of 2-hop away nodes on the single route is additionally connected via an alternative node. Throughout mathematical analysis we show the proposed protocol reveals higher message delivery rate than that of the Das's multi-path protocol, currently known as one of the most typical approaches related to DSR.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06d
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• pp.187-189
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• 2012

The medium access control (MAC) protocol is designed only for single channel in the IEEE 802.11 standard. That means the throughput of the network is limited by the bandwidth of the single channel. The multiple channels can be exploited to get more concurrent transmission. In this paper, we propose a novel Multi-channel MAC that utilizes the channel more efficiently than other Multi-channel MAC protocols.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.3
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• pp.405-415
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• 2012

In many applications a reader needs to determine whether a particular tag exists within a group of tags without a server. This is referred to as serverless RFID tag searching. A few protocols for the serverless RFID searching are proposed but they are the single tag search protocol which can search a tag at one time. In this paper, we propose a multi-tag search protocol based on a hash function and a random number generator which can search some tags at one time. For this study, we introduce a protocol which can resolve the problem of synchronization of seeds when communication error occurs in the S3PR protocol[1], and propose a multi-tag search protocol which can reduce the communication overhead. The proposed protocol is secure against tracking attack, impersonation attack, replay attack and denial-of-service attack. This study will be the basis of research for multi-tag serach protocol.

• Journal of Communications and Networks
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• v.13 no.1
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• pp.43-49
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• 2011

In this paper, a new medium access control (MAC) protocol entitled three-phase multiple access with continual contention resolution (TPMA-CCR) is proposed for wireless multi-hop ad hoc networks. This work is motivated by the previously known three-phase multiple access (TPMA) scheme of Hou and Tsai [2] which is the suitable MAC protocol for clustering multi-hop ad hoc networks owing to its beneficial attributes such as easy collision detectible, anonymous acknowledgment (ACK), and simple signaling format for the broadcast-natured networks. The new TPMA-CCR is designed to let all contending nodes participate in contentions for a medium access more aggressively than the original TPMA and with continual resolving procedures as well. Through the systematical performance analysis of the suggested protocol, it is also shown that the maximum throughput of the new protocol is not only superior to the original TPMA, but also improves on the conventional slotted carrier sense multiple access (CSMA) under certain circumstances. Thus, in terms of performance, TPMA-CCR can provide an attractive alternative to other contention-based MAC protocols for multi-hop ad hoc networks.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.12
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• pp.1-9
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• 1997

The signaling protocol for B-ISDN should support variety of services including point-to-pont single-connection call, point-to-point multi-connection call and point-to-multipoint connection call. an efficient signaling protocol for point-to-point multi-connection call based on ITU-T Recommendation Q.298X is presented in this paper. Sequential establishment of madatory and optional connections and common routing scheme for synchronization, along with separation of information elements for establishement of multi-connection call are included in the proposed signaling protocol. Limited network resources can be used more efficiently by proposed sequential establishement of mandartory and optional connection for point-to-point multi-connection call which can provide multimedia services. And common routing can be provided effectively by proposed common routing scheme for connectios requiring synchronization like as video-phone and video-conference.