• 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 the Korea Institute of Information Security & Cryptology
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• v.20 no.6
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• pp.53-57
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• 2010

Recently, Lee et al. proposed a delegation-based authentication protocol for secure and private roaming service in global mobility networks. In this paper, we show that the protocol cannot protect the privacy of an user even though the protocol provides the user anonymity. To prove the weakness, we show that the protocol cannot provide the unlinkability and also examine the weakness of the protocol caused by the lack of the unlinkability.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.352-354
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• 1991

MAP is a standard communication protocol for manufactoring automation. In this paper we implemented IEEE 802.2 LLC class 3 protocol, which consist of type l(unacknowledged connecionless data transfer) mode and type 3 (acknowledged connectionless data transfer) mode. This implemented protocol is verified by the test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.1
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• pp.25-39
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• 1986

In this paper, we analyze the performance, particularly the flow control mechanism, of the CCITT X.25 protocol in a packet-switched network. In this analysis, we consider the link and packet layers separately, and investigate the performance in three measures; normalized channel throughput, mean transmission time, and transmission efficiency. Each of these measures is formulated in terms of given protocol parameters such as windos size, $T_1$ and $T_2$ values, message length, and so forth. We model the service procedure of the inpur traffic based on the flow control mechanism of the X.25 protocol, and investigate the mechanism of the sliding window flow control with the piggybacked acknowlodgment scheme using a discrete-time Markov chain model. With this model, we study the effect of variation of the protoccol parameters on the performance of the X.25 protocol. From the numerical results of this analysis one can select the optimal valuse of the protocol parameters for different channel environments. it has been found that to maintain the trasnmission capacity satisfactorily, the window size must be greater than or equal to 7 in a high-speed channel. The time-out value, $T_1$, must carefully be selected in a noisy channel. In a normal condition, it should be in the order of ls. The value of $T_2$ has some effect on the transmission efficiency, but is not critical.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.4
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• pp.691-699
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• 2009

Recently, the ERO protocol has been adopted as a standard to protect the routing optimization mode introduced by MIPv6. This protocol uses the public key cryptography and the early binding update method to improve the Return Routeability protocol while optimizing both security and performance. On the other hand, though various security approaches including the ERO protocol have been proposed for MIPv6, they lack formal verification. Especially, to our best knowledge, there is no formal analysis on the ERO protocol. In order to provide a good example for formal analysis on MIPv6 security protocols, this paper verifies the correctness of the ERO protocol through BAN-logic. For this goal, BAN-logic is extended to consider the address tests on the mobile nodes's CoA and HoA. It is expected that the analysis presented in this paper will be useful for the formal verifications on the security protocols related to MIPv6.

• Convergence Security Journal
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• v.6 no.1
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• pp.45-53
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• 2006

It has been proposed that several RFID authentication protocols based on hash chain. Status based authentication protocol and challenge-response based authentication protocol are secured against location tracking attacks, spoofing attacks, replay attacks, traffic analysis attacks but are vulnerable to Dos attacks. RFID authentication protocol with strong resistance against traceability and denial of service attack is secured against location tracking attack, spoofing attacks, replay attacks, DoS attacks but are vulnerable to traffic analysis attacks. The present study suggests a more secure and lightweight RFID authentication protocol which is combining the advantages of hash-chain authentication protocol and RFID authentication protocol with strong resistance against traceability and denial of service attack. The results of the secure analysts for a proposed protocol are illustrated that it is secured against location tracking attacks, spoofing attacks, replay attacks, traffic analysis attacks, Dos attacks and is a lightweight operation between server and tag.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.49-56
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• 2005

To reduce server bottlenecks in client-server computing, each client may have its own cache for later reuse. The pessimistic approach for cache management protocol leads to unnecessary waits, because, it can not be commit a transaction until the transaction obtains all requested locks. In addition, optimistic approach tends to make needless aborts. This paper suggests an efficient optimistic protocol that overcomes such shortcomings. In this paper, we present a simulation-based analysis on the performance of our scheme with other well-known protocols. The analysis was executed under the Zipf workload which represents the popularity distribution on the Web. The simulation experiments show that our scheme performs as well as or better than other schemes with low overhead.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.863-869
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• 2006

The existing Europe Standard, EN 50159 with respect of safety of railway signalling communication protocol has been changed into International Standard, IEC 62280. This Standard presents the requirement for safe communication between safety-related devices which connects with transmission system, there are both closed and open transmission system. Regardless of this international Standards, the communication protocol for interface between CTC communication server and external facilities has been standardized several years ago in our country, so this is applied to integrated CTC system in KORAIL. Two Standards are currently standardized as a protocol between CTC and external facilities, these standard protocols are also required high level safety as a communication link which is transmitted vital control information in common with the train control system. For that reason, we have made analysis of requirement for the safe transmission required by international standard. Under this analysis, we have studied safety features of communication protocol applying to our standard. In other words, we have researched that how many the requirement from international standard for safe transmission is reflected in domestic standard protocol, and also whether our standard makes sure of safety enough or not.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.389-399
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• 1998

The DMR-II shared-medium access control protocol was developed for the ATM access network users to supper the isochronous traffic and the non-isochronous traffic simultaneously under the bandwidth-skating environment. In this paper we analyze the performance of the DMR-II protocol by using both the analytical analysis and the simulation method. Under the ATM access network environment, the performance analysis result shows that the DMR-II protocol maintains the delay variation of the isochronous traffic beyond the threshold value, and satisfies the delay time criteria of the non-isochronous traffic by supporting the priority service. Moreover the result shows high network utilization over 130% due to the destination release mechanism of the DMR-II protocol.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.10 no.4
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• pp.33-46
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• 2000

IPsec is a protocol suite to protect the data communication between computers on internet and many VPNs(Virtual Private Networks) use IPsec protocol. IKE protocol is used to exchange keys in IPsec. Formal analysis method is used increasingly in computer science to increase the reliability of a system. In this paper, the IKE protocol is analyzed formally. This paper shows that IKE with Authentication with Signature and Authentication with Pre-Shared Key is safe, but Authentication with Public Key Encryption and A Revised Method of Authentication with Public Key Encryption are safe only with the assumption that a participant has the correct public key of the correspondent. To make sure that a participant has the correct public key of the correspondent, the usage of certificate is recommended.