• The KIPS Transactions:PartC
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• v.15C no.4
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• pp.227-238
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• 2008

As the internet users rise up rapidly, DNS information forgery can cause severe socio-economic damages. However, most studies on DNS information security reached the breaking point in applying to actual circumstances because of the limit of existing DNS system version, the increasement of management burden and etc. The paper proposes the real-time method for detecting cache poisoning of DNS system independent of analysing the DNS forgery types in the current DNS service environment. It also proposes the method of enhancing the reliability for the cache information of Recursive DNS system by post-verifying the cache information of the DNS system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.8
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• pp.3501-3518
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• 2020

The method of DNS data collection is one of the most important parts of DNS simulation. DNS data contains a lot of information. When it comes to analyzing the DNS security issues by simulation on the cyber range with customized features, we only need some of them, such as IP address, domain name information, etc. Therefore, the data we need are supposed to be light-weighted and easy to manipulate. Many researchers have designed different schemes to obtain their datasets, such as LDplayer and Thales system. However, existing solutions consume excessive computational resources, which are not necessary for DNS security simulation. In this paper, we propose a light-weighted active data collection method to prepare the datasets for DNS simulation on cyber range. We evaluate the performance of the method and prove that it can collect DNS data in a short time and store the collected data at a lower storage cost. In addition, we give two examples to illustrate how our method can be used in a variety of applications.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.3
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• pp.193-204
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• 2006

In most existing distributed Web systems, incoming requests are distributed to servers via Domain Name System (DNS). Although such systems are simple to implement, the address caching mechanism easily results in load unbalancing among servers. Moreover, modification of the DNS is necessary to load considering the server's state. In this paper, we propose a new dynamic load balancing method using dynamic DNS update and round-robin mechanism. The proposed method performs effective load balancing without modification of the DNS. In this method, a server can dynamically be added to or removed from the DNS list according to the server's load. By removing the overloaded server from the DNS list, the response time becomes faster. For dynamic scheduling, we propose a scheduling algorithm that considers the CPU, memory, and network usage. We can select a scheduling policy based on resources usage. The proposed system can easily be managed by a GUI-based management tool. Experiments show that modules implemented in this paper have low impact on the proposed system. Furthermore, experiments show that both the response time and the file transfer rate of the proposed system are faster than those of a pure Round-Robin DNS.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.273-282
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• 2007

The Domain Name System (DNS) is the core system for managing Internet address resources, providing the most fundamental naming service. Currently, the DNS is classified into a tree structure. In this structure, it is difficult to normally access to the lower DNS, when there is an error in the upper DNS. Such a risk still remains even when a supplementary DNS is operated. However, due to the merit of the DNS enabling fast searches, it is impracticable to abandon the current tree structure. To efficiently correspond to DNS errors, this study suggests a method where the merit of the current tree structure is kept, while a temporary operation of the local DNS is available when errors occur by adding a horizontal and independent DNS structure.

• Journal of Communications and Networks
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• v.11 no.4
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• pp.416-427
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• 2009

Domain name system (DNS) is a primary identification mechanism for Internet applications. However, DNS resolutions often take an unbearably long time, and this could seriously impair the consistency of the service quality of Internet applications based on DNS such as World Wide Web. Several approaches reduce DNS resolution time by proactively refreshing expired cached records or prefetching available records beforehand, but these approaches have an inherent problem in that they cause additional DNS traffic. In this paper, we propose a DNS resolution time reduction scheme, named renewal using piggyback (RUP), which refreshes expired cached records by piggybacking them onto solicited DNS queries instead of by issuing additional DNS queries. This method decreases both DNS resolution time and DNS traffic since it reduces the number of queries generated to handle a given DNS resolution without generating additional DNS messages. Simulation results based on two large independent DNS traces show that our proposed approach much reduces not only the DNS resolution time but also the DNS traffic.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.11
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• pp.1451-1461
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• 2019

DNS spoofing is an attack in which an attacker intervenes in the communication between client and DNS server to deceive DNS server by responding to a fake IP address rather than actual IP address. It is possible to implement a pharming site that hacks user ID and password by duplicating web server's index page and simple web programming. In this paper we have studied web spoofing attack that combines DNS spoofing and pharming site implementation which leads to farming site. We have studied DNS spoofing attack method, procedure and farming site implementation method for portal server of this university. In the case of Kyungsung Portal, bypassing attack and hacking were possible even though the web server was SSL encrypted and secure authentication. Many web servers do not have security measures, and even web servers secured by SSL can be disabled. So it is necessary that these serious risks are to be informed and countermeasures are to be researched.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1231-1234
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• 2006

MANET에서 노드들은 DNS 서비스를 이용하기 위하여 DNS 서버를 구성해야 한다. 하지만 DNS 서버를 구성하는 노드는 다른 노드에 비해 많은 자원을 소비하게 되므로 DNS 서버는 주기적으로 교체되어야 한다. 따라서 본 논문은 클러스터링 기법을 활용하여 클러스터내의 노드들을 관리하는 CDNS 서버를 구성하고, 전체 CDNS 서버를 관리하는 RDNS 서버를 구성하여 네트워크의 모든 노드들이 DNS 서비스에 참여하는 분산 클러스터 기법의 DNS 시스템을 제안한다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.10 no.2
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• pp.3-12
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• 2000

In this paper we propose a new algorithm which resolves the inconsistency problems occurring when DNS severs are employed as elements of PKI. The inconsistency may take place between primary name servers and secondary name servers and between cached certificate and original certificate. The former can be removed by adapting RFC 1996 NOTIFY opcode for DNS. In order to eliminate the latter type of inconsistency we develope a new algorithm which is implemented with two additional RR(Resource Record). The present algorithm is designed such that DNS contacts the destination DNS prior to returning public key to users. Therefore the inconsistency problem occurring when DNS is operated as PKI can be eliminated by using the proposed adaptation and algorithm.

• The Transactions of the Korea Information Processing Society
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• v.6 no.1
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• pp.134-147
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• 1999

The DNS provides naming services which are the basis for the application of the Internet and the security of the DNS should be provided for the security of the Internet. Recently IETF proposed a method which guarantees the integrity of DNS database contents and DNS queries/replies and distributes host public keys. In this paper we describe the design and implementation of the secure DNS which is built based on the IETF proposal and extended to facilitate its sue and management. In the extended secure DNS, DNS servers are used ad the directory system in a public key infrastructure and stores/distributes user public key certificates. The Web-based management interface and security log functions are added and the extended secure DNS is being built so that new cryptographic algorithms can be easily added.

• The KIPS Transactions:PartD
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• v.16D no.6
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• pp.921-926
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• 2009

Vulnerabilities in software can result in many social and economic problems once it has already been deployed and put to use. Thus, the vulnerabilities should be seriously taken into consideration from the beginning step of software development. A modeling and simulation method for software can be adopted as a testing tool for establishing vulnerability inspection strategies. For verification of usability of this strategy, in this paper, we modeled the behavior of a DNS system using Ptolemy and the simulation was performed. The result shows that a well-known vulnerability of DNS server could be effectively found, which confirms that the modeling and simulation can be used for vulnerability testing.