• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.1
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• pp.41-52
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• 2024

Security audits of IPsec VPNs are crucial for identifying vulnerabilities caused by implementation flaws or misconfigurations, as well as investigating incidents. Nevertheless, auditing IPsec VPN presents noteworthy challenge due to the encryptiong of network contents which ensere confidentiality, integrity, authentications and more. Some researchers have suggested using man-in-the-middle(MITM) techniques to overcome this challenge. MITM techniques require direct participation in the network and prior knowledge of the pre-shared key for authentication. This causes temporary network disconnection for security audits, and it is impossible to analyse data collected before the audit. In this paper, we present an analysis technique aimed at ensuring network continuity without relying on a specific IPsec VPN topologies or authentication method. Therefore, it is anticipated that this approach will be effective, practical and adaptable for conducting IPsec VPN security

• Journal of information and communication convergence engineering
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• v.1 no.4
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• pp.213-216
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• 2003

A VPN is widely used in a communications environment which access is controlled to permit peer connections only within a defined community of interest. It is constructed through some form of partitioning of a common underlying communication medium, where this underlying communications medium provides services to the network on a non-exclusive basis. In this paper, we have analyzed a variety of architecture to implement Giga bps VPN system. The proposed architecture will satisfy the needs of clients who adopt Giga bps VPN system in the various environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6C
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• pp.659-667
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• 2003

IPsec refers to a standardized set of security protocols and algorithms which can provide the integrity, the authentication and the confidentiality services for IP packets in the Internet. Between two security gateways, IPsec provides the access control, the connectionless Integrity, data origin authentication, the anti-replay, and the confidentiality services, not only to the IP layer but also to the upper layers. In this paper, we describe a VPN (Virtual Private Network) testbed configuration using the FreeS/WAN and analyze the ISAKMP messages exchanged between the linux security gateway during the IKE SA setup. Also, we describe our development of an IPSEC encryption verification tool which can be used conveniently by VPN administrators.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.195-199
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• 2002

Requirements of a well-designed VPNs(Virtual Private Networks) are scalability, performance, reliability, ease of management, interoperability and security. Tunneling is a important technology to support these. This paper researches VPNs tunneling technologies used currently and proposes VPN service models for the scalability that is a problem in VPNs and for the resource limit of Mobile Station in Mobile VPNs environment.

• The KIPS Transactions:PartC
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• v.12C no.1 s.97
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• pp.1-10
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• 2005

Electronic Data Interchange(EDI) between a number of companies goes on increasing on the internet. Although a conventional EDI system reduces business process efforts, time, resources, etc., important information is easily and frequently exposed by well trained hackers and crackers, which inflict a severe loss on the company and even put the company under a crisis. This study integrates the conventional EDI system and Virtual Private Tet(VPN) to maximize an overall efficiency of speed and security in data transferring by the level of importance. The EDI system interfaced to IPSec and L2TP of VPN allows us to select two modes : the one focuses on a high speed with a low or a medium level security or the other does on a high level security with a low or a medium level speed. Both the company and the end users get a lot of tangible and intangible advantages by integrating the EDI system and VPN.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.721-724
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• 2003

본 논문에서는 CDMA 3G 환경에서의 Wireless VPN에 있어서의 문제점을 분석하고 설계/구현 방안을 제시하고자 한다. Wireless VPN의 최종 목표는 Wireline VPN과의 통합을 이루어서 진정한 Mobile VPN을 구현하는 것이지만 아직까지 Mobile IP 지원에 대한 국제 표준이 완전히 정비되지 않은 상태이고 또한 Mobile VPN에 대한 기술적 검증이 이루어진 적이 없기 때문에 본 논문에서는 Wireless VPN에 초점을 맞추도록 한다.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.1
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• pp.51-57
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• 2007

In this paper we introduce the concept of MPLS-based VPN and propose a scheme for providing VPN services in MPLS networks. Furthermore, we design the control components and the operational procedures and evaluated the performance of traditional VPN implementation methods and MPLS-based VPN. In this scheme it is possible to solve several problems that IP-based VPN pertains via the allocation of VPN ID and virtual space without tunneling, thereby providing effective VPN services. In other words, the MPLS-based VPN scheme uses MPLS networking technology together with the PSTN which can achieve a perfect segregation of user traffic on per-customer basis in a physical link and can guarantee high reliability and security levels. Specially, in the perspective of customers, it can save networking facilities installation and maintenance costs considerably. On the contrary, it possesses some shortcomings in that its deployment tends to be restricted within an ISP's network boundary and it is vulnerable to external security break-ins when going through public networks such as the Internet due to its lack of data encryption capability.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.6
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• pp.1065-1078
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• 2014

Considering the safety of the data and performance, it can be said that the performance of the AES algorithm in a symmetric key-based encryption is the best in the IPSec-based VPN. When using the AES algorithm in IPSec-based VPN even with the expensive hardware encryption card such as OCTEON Card series of Cavium Networks, the Performance of VPN works less than half of the firewall using the same hardware. In 2008, Intel announced a set of 7 AES-NI instructions in order to improve the performance of the AES algorithm on the Intel CPU. In this paper, we verify how much the performance IPSec-based VPN can be improved when using seven sets of AES-NI instruction of the Intel CPU.

• Journal of KIISE:Information Networking
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• v.29 no.1
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• pp.31-39
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• 2002

The VPN(Virtual Private Network) is a private network constructed logically on a public network infrastructure. There have been numerous studies to support the VPN services by using different technologies such as IP in IP, GRE, L2TP, MPLS and so on. Among these technologies, MPLS has shown many merits in aspects of QoS, security, and management, compared with other technologies. As an enhancement of the VPN that is controlled by MPLS PE(Provider Edge) routers, this paper presents the VPN controlled by MPLS CE(Customer Edge) routers. The functional architecture of the CE based VPN and operations of the CE routers are described along with the performance comparison of CE based MPLS VPN. It has been shown that the CE based VPN has more advantages than PE based VPN with respect to independency, scalability, security, and complexity.

• Journal of Internet Computing and Services
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• v.23 no.6
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• pp.27-37
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• 2022

Virtual private network (VPN) services are used in various environments related to national security, such as defense companies and defense-related institutions where digital communication environment technologies are diversified and access to network use is increasing. However, the number of cyber attacks that target vulnerable points of the VPN has annually increased through technological advancement. Thus, this study identified security requirements by performing STRIDE threat modeling to prevent potential and new vulnerable points that can occur in the VPN. STRIDE threat modeling classifies threats into six categories to systematically identify threats. To apply the proposed security requirements, this study analyzed functions of the VPN and formed a data flow diagram in the VPN service process. Then, it collected threats that can take place in the VPN and analyzed the STRIDE threat model based on data of the collected threats. The data flow diagram in the VPN service process, which was established by this study, included 96 STRIDE threats. This study formed a threat scenario to analyze attack routes of the classified threats and derived 30 security requirements for each element of the VPN based on the formed scenario. This study has significance in that it presented a security guideline for enhancing security stability of the VPN used in facilities that require high-level security, such as the Ministry of National Defense (MND).