• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.157-163
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• 2009

With the wide usage of internet in many fields, networks are being exposed to many security threats, such as DDoS attack and worm/virus. For enterprise network, prevention failure of network security causes the revealing of commercial information or interruption of network services. In this paper, we propose a method of prevention of DDoS attacks for enterprise network based on traceback and network traffic analysis. The model of traceback implements the detection of IP spoofing attacks by the cooperation of trusted adjacent host, and the method of network traffic analysis implements the detection of DDoS attacks by analyzing the traffic characteristic. Moreover, we present the result of the experiments, and compare the method with other methods. The result demonstrates that the method can effectively detect and block DDoS attacks and IP spoofing attacks.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.6
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• pp.1261-1269
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• 2017

Feistel Networks are one of the most well-known schemes to design block ciphers. Generalized Feistel Networks are used to construct only block ciphers but also hash functions. Many generic attacks on Feistel schemes have been studied. Among these attacks, recently proposed meet-in-the-middle attacks are one of the most effective attacks. In this paper, we analyze the security of meet-in-the-middle attacks on generalized Feistel Networks.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.138-145
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• 2019

With the application of digital technology to safety-critical infrastructures, cyber-attacks have emerged as one of the new dangerous threats. In safety-critical infrastructures such as a nuclear power plant (NPP), a cyber-attack could have serious consequences by initiating dangerous events or rendering important safety systems unavailable. Since a cyber-attack is conducted intentionally, numerous possible cases should be considered for developing a cyber security system, such as the attack paths, methods, and potential target systems. Therefore, prior to developing a risk-informed cyber security strategy, the importance of cyber-attacks and significant critical digital assets (CDAs) should be analyzed. In this work, an importance analysis method for cyber-attacks on an NPP was proposed using the probabilistic safety assessment (PSA) method. To develop an importance analysis framework for cyber-attacks, possible cyber-attacks were identified with failure modes, and a PSA model for cyber-attacks was developed. For case studies, the quantitative evaluations of cyber-attack scenarios were performed using the proposed method. By using quantitative importance of cyber-attacks and identifying significant CDAs that must be defended against cyber-attacks, it is possible to develop an efficient and reliable defense strategy against cyber-attacks on NPPs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2610-2628
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• 2019

Advanced persistent threats (APTs) are constant attacks of specific targets by hackers using intelligent methods. All current internal infrastructures are constantly subject to APT attacks created by external and unknown malware. Therefore, information security officers require a framework that can assess whether information security systems are capable of detecting and blocking APT attacks. Furthermore, an on-line evaluation of information security systems is required to cope with various malicious code attacks. A regular evaluation of the information security system is thus essential. In this paper, we propose a dynamic updated evaluation framework to improve the detection rate of internal information systems for malware that is unknown to most (over 60 %) existing static information security system evaluation methodologies using non-updated unknown malware.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.595-598
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• 2014

The cyber attacks of recent attacks that target zero-day exploit security vulnerabilities before the security patch is released (Zero Day) attack, the web site is without the Lord. These attacks, those that use the vulnerability of security that is built into the software itself is in most cases, cyber attacks that use the vulnerability of the security of the source code, in particular, has a characteristic response that are difficult to security equipment. Therefore, it is necessary to eliminate the security vulnerability from step to implement the software to prevent these attacks. In this paper, we try to design a Secure Coding Guide support tool to eliminate the threat of security from the stage of implementation.

• Journal of Information Technology Services
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• v.20 no.5
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• pp.119-136
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• 2021

Since the global spread of COVID-19, social distancing and untact service implementation have spread rapidly. With the transition to a non-face-to-face environment such as telework and remote classes, cyber security threats have increased, and a lot of cyber compromises have also occurred. In this study, cyber-attacks and response cases related to COVID-19 are summarized in four aspects: cyber fraud, cyber-attacks on companies related to COVID-19 and healthcare sector, cyber-attacks on untact services such as telework, and preparation of untact services security for post-covid 19. After the outbreak of the COVID-19 pandemic, related events such as vaccination information and payment of national disaster aid continued to be used as bait for smishing and phishing. In the aspect of cyber-attacks on companies related to COVID-19 and healthcare sector, we can see that the damage was rapidly increasing as state-supported hackers attack those companies to obtain research results related to the COVID-19, and hackers chose medical institutions as targets with an efficient ransomware attack approach by changing 'spray and pray' strategy to 'big-game hunting'. Companies using untact services such as telework are experiencing cyber breaches due to insufficient security settings, non-installation of security patches, and vulnerabilities in systems constituting untact services such as VPN. In response to these cyber incidents, as a case of cyber fraud countermeasures, security notices to preventing cyber fraud damage to the public was announced, and security guidelines and ransomware countermeasures were provided to organizations related to COVID-19 and medical institutions. In addition, for companies that use and provide untact services, security vulnerability finding and system development environment security inspection service were provided by Government funding programs. We also looked at the differences in the role of the government and the target of security notices between domestic and overseas response cases. Lastly, considering the development of untact services by industry in preparation for post-COVID-19, supply chain security, cloud security, development security, and IoT security were suggested as common security reinforcement measures.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2204-2220
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• 2011

Without providing a proper security measure to the handover procedure in Mobile WiMAX, several security attacks can be mounted. Even though security schemes have been previously proposed for this purpose, they are still vulnerable to several security attacks due to fatal design flaws. A newly proposed security scheme in this paper is based on the framework of authentication domain and concept of handover ticket. A method of establishing security associations within the authentication domain is proposed, and a lightweight security measure to protect the management messages associated with the handover is also proposed. Especially, using the handover ticket, the new security scheme can defend against a Redirection Attack arising from a compromised base station. The new security scheme is comparatively analyzed with the previous security schemes in terms of Replay, Session Hijacking, Man-In-The-Middle, and Redirection attacks.

• International Journal of Computer Science & Network Security
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• v.23 no.4
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• pp.111-115
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• 2023

Knowledge Based Authentication is the most well-known technique for user authentication in a computer security framework. Most frameworks utilize a straightforward PIN (Personal Identification Number) or psssword as an data authenticator. Since password based authenticators typically will be software based, they are inclined to different attacks and weaknesses, from both human and software.Some of the attacks are talked about in this paper.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3888-3910
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• 2018

As an increasing number of defense methods against control-data attacks are deployed in practice, control-data attacks have become challenging, and non-control-data attacks are on the rise. However, defense methods against non-control-data attacks are still deficient even though these attacks can produce damage as significant as that of control-data attacks. We present a method to defend against non-control-data attacks using influence domain monitoring (IDM). A definition of the data influence domain is first proposed to describe the characteristics of a variable during its life cycle. IDM extracts security-critical non-control data from the target program and then instruments the target for monitoring these variables' influence domains to ensure that corrupted variables will not be used as the attackers intend. Therefore, attackers may be able to modify the value of one security-critical variable by exploiting certain memory corruption vulnerabilities, but they will be prevented from using the variable for nefarious purposes. We evaluate a prototype implementation of IDM and use the experimental results to show that this method can defend against most known non-control-data attacks while imposing a moderate amount of performance overhead.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.9
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• pp.1374-1381
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• 2022

Existing research on security technology related to network attack response has focused on research using hardware network security technology, network attacks that wiretap and wiretap network packets, denial of service attack that consumes server resources to bring down the system, and network by identifying vulnerabilities before attack. It is classified as a scanning attack. In addition, methods for increasing network security, antivirus vaccines and antivirus systems have been mainly proposed and designed. In particular, many users do not fully utilize the security function of the router. In order to overcome this problem, it is classified according to the network security level to block external attacks through layered security management through layer-by-layer experiments. The scope of the study was presented by examining the security technology trends of edge routers, and suggested methods and implementation examples to protect from threats related to edge router-based network attacks.