• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.6
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• pp.526-532
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• 2004

The insufficiency on IP address cause to develope a new internet protocol, IPv6 that the length of address field is expanded. But there are actually many problems on applying and operating this standard for internet. Though NAT(Network Address Translation) is instead of it, NAT has the characteristics that is not allowed to access from outside. This is a big merit in security but a week point because the access from outside should be allowed when a small organization operate web sever or mail server. Therefore, this paper proposes the expanded NAT which can solve such problems as modifying the table of NAT. Furthermore, the function of existing VPN(Virtual Private Network) will be acceptable partly through such a method that provide the linkage among VPNs.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.215-218
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• 2011

VoIP(Voice over Internet Protocol) 서비스는 기존의 음성전화 서비스(Public Switched Telephone Network, PSTN)와 달리 IP 프로토콜을 이용한 저렴한 통신비용 등의 장점이 있는 음성통신 기술로써, 기존의 아날로그 음성전화 서비스를 대신하는 서비스이며, 새로운 인터넷 융합서비스로 많은 사용자가 이용하고 있다. 하지만 VoIP 서비스가 인터넷망을 이용함으로 IP Spoofing, DoS (Denial of Server) / DDoS(Distributed Denial of Service), 등의 여러 가지 보안의 문제점을 가지고 있다. VoIP 서비스에서 DDoS 공격은 Proxy 서버 등에 대량의 공격 메시지를 보냄으로써 서버의 자원을 고갈시켜 정상적인 서비스를 하지 못하게 한다. DoS, DDoS 공격 중 Invite Flooding 공격은 1분에 수천 개의 Invite 메시지를 보내 회선의 자원을 고갈시키는 공격이다. 특히 IP/Port 위조하여 공격 경우 공격 패킷 탐지하기 어려우므로 차단할 수 없다. 따라서 본 논문에서는 VoIP의 DoS/DDoS 중 하나인 Invite Flooding 공격 시 SIP Proxy Server에서 메시지 분산시키는 방법과 MAC Address와 사용자 번호 등 IP 이외의 고정적인 사용자 정보를 확인하여 공격을 탐지하고, 공격 Agent에 감염된 Phone을 공격차단서비스로 보내 복구시키는 방법을 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.12C
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• pp.1228-1237
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• 2002

Network management is composed of five major functional areas, fault, configuration, account, performance and security management in the ITU standards. Configuration management identifies, exercises control over, collects data from network element node system and provides data to the management systems. The proposed architecture is designed based on the Distributed Processing Environment of CORBA(Common Object Request Broker Architecture) Spec v2.3. In this paper, configuration management system has been designed and implemented with layered managed object. It provides that integrated management of various data link layer technology. We suggest MIB(Management Information Base)/MIT(Management Information Tree) to support integrated management and distributed environment.

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.77-84
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• 2011

In this paper we implement a 6LoWPAN protocol on the MICAz sensor platform, which could minimize packet re-transmission, and support security primitives for packet integrity and confidentiality. And we also present a performance evaluation of the implemented protocol calculated according to the cryptographic algorithms. In the re-transmission method, time stamp, nonce, and checksum are considered to protect replay attacks. As cryptographic algorithms, AES, 3DES, SHA2, and SHA1 are implemented. If transmission errors (thus, packet losses) and the number of hops are increase then, packet re-transmissions are increase exponentially from the experimental results. Also, the result shows that cryptographic operations take more time than packet re-transmission time.

• Journal of the Korea Society for Simulation
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• v.12 no.4
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• pp.25-40
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• 2003

With the growing usage of the networks, the world-wide Internet has become the main means to exchange data and carry out transactions. It has also become the main means to attack hosts. To solve the security problems which occur in the network such as Internet, we import software products of network security elements like an IDS (Intrusion Detection System) and a firewall. In this paper, we have designed and constructed the general simulation environment of network security model composed of multiple IDSes and a firewall which coordinate by CNP (Contract Net Protocol) for the effective detection of the intrusion. The CNP, the methodology for efficient integration of computer systems on heterogeneous environment such as distributed systems, is essentially a collection of agents, which cooperate to resolve a problem. Command console in the CNP is a manager who controls the execution of agents or a contractee, who performs intrusion detection. In the network security model, each model of simulation environment is hierarchically designed by DEVS(Discrete Event system Specification) formalism. The purpose of this simulation is that the application of rete pattern-matching algorithm speeds up the inference cycle phases of the intrusion detection expert system and we evaluate the characteristics and performance of CNP architecture with rete pattern-matching algorithm.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.4 s.304
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• pp.35-44
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• 2005

Face recognition out of biometrics is considerable interesting due to high performance and accessibility in applications to security such as access control and banking service. Therefore, a study on the protocol of the performance test is an important issue to understand the art-of state and to show a direction in future works, in addtion to developing algorithms. We present a design criterion for the performance test protocol of face recognition system and show the result of experiment executed on identification and verification scenario based on PCA algorithm and XM2VTS DB

• Journal of Intelligence and Information Systems
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• v.5 no.2
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• pp.63-78
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• 1999

협상은 상거래에 있어서 매우 중요한 요소 중 하나이다. 현재의 웹 기반 전자상거래 시스템은 이러한 중요한 협상 구조를 상거래에 잘 반영하지 못하는 문제점을 가지고 있다. 이러한 문제점중 기업과 소비자간의 미비한 협상 구조를 보안하기 위해 실세계 상거래에서 존재하는 점원을 전자상거래상의 가상점원으로 모델링하여 회사의 정책과 구매자의 특성을 반영하여 구매자와 전략적으로 자동 협상을 수행할 수 있는 에이전트의 구조를 설계하고 구현하였다. 협상은 매우 복잡한 구조를 가지고 있다. 이러한 협상 구조를 지원하기 위해서는 상호간의 제안을 표현하고, 그 제안에 대한 평가 내용과 결정사항을 전달할 수 있는 언어적인 구조가 필요하며, 협상의 대상이 되는 사안들의 특성을 반영할 수 있는 표현 구조도 요구된다. 또한 이러한 협상에서 전략을 세우고 알맞은 제안을 제시하며 상대의 제안에 대하여 전략적으로 반응할 수 있는 의사결정 모델이 요구된다. 본 논문에서는 회사의 정책 모델과 구매자의 모델을 정의하고 이를 이용한 협상 모델을 설계 구현하였다. 협상 구조의 모델링을 위해 KQML(Knowledge Query Manipulation Language)을 기반으로 전자상거래 프로토콜로 설계하고, 논쟁 기반 협상 모델을 기초로 협상언로를 설계하였다. 또한 협상에서의 전략적인 의사결정을 위해 게임이론을 이용하고, 규칙 기반 시스템으로 이를 보충하였다. 마지막으로 가상점원 모델을 바탕으로 조립 컴퓨터 판매를 위한 가상점원을 구현하였고, 이에 대한 실험을 통하여 가상점원의 유용성을 보였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.177-180
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• 2015

As network technology advances hacking techniques are also evolving. This paper proposes design of a packet analyzer to monitor and analyze data packets in networks. The proposed packet analyzer offers functions such as packet sniffing, filtering and statistics. We implemented a prototype packet analyzer in C# .NET development environment using SharPcap.

• The KIPS Transactions:PartC
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• v.13C no.3 s.106
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• pp.283-294
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• 2006

Hostile network traffic is often different from normal traffic in ways that can be distinguished without knowing the exact nature of the attack. In this paper, we propose a new anomaly detection method using inbound network traffic distributions. For this purpose, we first characterize the traffic of a real campus network by the distributions of IP protocols, packet length, destination IP/port addresses, TTL value, TCP SYN packet, and fragment packet. And then we introduce the concept of entropy to transform the obtained baseline traffic distributions into manageable values. Finally, we can detect the anomalies by the difference of entropies between the current and baseline distributions. In particular, we apply the well-known denial-of-service attacks to a real campus network and show the experimental results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.815-825
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• 2015

DNP3(Distributed Network Protocol) is one of the most representative protocols which is used in SCADA(Supervisory Control and Data Acquisition) system. IEC 62351 is listing the integrity, confidentiality, availability and non-repudiation or accountability as the security requirement. However, IEEE Std. 1815 that is DNP3 standards does not define a mechanism for non-repudiation or accountability. In this paper, we propose a non-repudiation of origin technique about the sender of critical ASDU and implement the proposed scheme using software such as OpenSSL and SCADA source code library.