• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2240-2250
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• 2016

MIFARE Classic is the most popular contactless smart card, which is primarily used in the management of access control and public transport payment systems. It has several security features such as the proprietary stream cipher Crypto 1, a challenge-response mutual authentication protocol, and a random number generator. Unfortunately, multiple studies have reported structural flaws in its security features. Furthermore, various attack methods that target genuine MIFARE Classic cards or readers have been proposed to crack the card. From a practical perspective, these attacks can be partitioned according to the attacker's ability. However, this measure is insufficient to determine the optimal attack flow due to the refined random number generator. Most card-only attack methods assume a predicted or fixed random number, whereas several commercial cards use unpredictable and unfixable random numbers. In this paper, we propose optimal MIFARE Classic attack procedures with regards to the type of random number generator, as well as an adversary's ability. In addition, we show actual attack results from our portable experimental setup, which is comprised of a commercially developed attack device, a smartphone, and our own application retrieving secret data and sector key.

• Convergence Security Journal
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• v.23 no.4
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• pp.33-41
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• 2023

In recent years, advanced persistent threat (APT) attack organizations have exploited various vulnerabilities and attack techniques to target companies and institutions with national core technologies, distributing ransomware and demanding payment, stealing nationally important industrial secrets and distributing them on the black market (dark web), selling them to third countries, or using them to close the technology gap, requiring national-level security preparations. In this paper, we analyze the attack methods of attack organizations such as Kimsuky and Lazarus that caused industrial secrets leakage damage through APT attacks in Korea using the MITRE ATT&CK framework, and derive 26 cybersecurity-related administrative, physical, and technical security requirements that a company's security system should be equipped with. We also proposed a security framework and system configuration plan to utilize the security requirements in actual field. The security requirements presented in this paper provide practical methods and frameworks for security system developers and operators to utilize in security work to prevent leakage of corporate industrial secrets. In the future, it is necessary to analyze the advanced and intelligent attacks of various APT attack groups based on this paper and further research on related security measures.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.1
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• pp.91-101
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• 2017

API call sequence analysis is a kind of analysis using API call information extracted in target program. Compared to other techniques, this is advantageous as it can characterize the behavior of the target. However, existing API call sequence analysis has an issue of identifying same characteristics to different function during the analysis. To resolve the identification issue and improve performance of analysis, this study includes the method of API abstraction technique in addition to existing analysis. From there on, similarity between target programs is computed and clustered into similar types by applying LSH to abstracted API call sequence from analyzed target. Thus, this study can attribute in improving the accuracy of the malware analysis based on discovered information on the types of malware identified.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.6
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• pp.1385-1397
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• 2015

The Proxy DLL is a mechanism using a normal characteristics of Windows. Specific malware is executed via this mechanism after intrusion into a system which is targeted. If a intrusion of malware is successful, malware should be executed at least once. For execution, malware is disguised as a Windows Library. The malware of Winnti group is a good case for this. Winnti is a group of Chinese hacking groups identified by research in the fall of 2011 at Kaspersky Lab. Winnti group activities was negatively over the years to target the online video game industry, in this process by making a number of malware infected the online gaming company. In this paper, we perform research on detection techniques of Proxy DLL malware which is disguised as a Windows library through Winnti group case. The experiments that are undertaken to target real malware of Winnti show reliability of detection techniques.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.6
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• pp.1383-1392
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• 2019

Adversarial attack, which geneartes adversarial data to make target model misclassify the input data, is able to confuse real life applications of classification models and cause severe damage to the classification system. An Black-box adversarial attack learns a substitute model, which have similar decision boundary to the target model, and then generates adversarial data with the substitute model. Jacobian-based data augmentation is used to synthesize the training data to learn substitutes, but has a drawback that the data synthesized by the augmentation get distorted more and more as the training loop proceeds. We suggest data augmentation with 'decay factor' to alleviate this problem. The result shows that attack success rate of our method is higher(around 8.5%) than the existing method.

• International Journal of Computer Science & Network Security
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• v.22 no.12
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• pp.185-196
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• 2022

The Internet of Things (IoT) has become more and more widespread in recent years, thus attackers are placing greater emphasis on IoT environments. The IoT connects a large number of smart devices via wired and wireless networks that incorporate sensors or actuators in order to produce and share meaningful information. Attackers employed IoT devices as bots to assault the target server; however, because of their resource limitations, these devices are easily infected with IoT malware. The Distributed Denial of Service (DDoS) is one of the many security problems that might arise in an IoT context. DDOS attempt involves flooding a target server with irrelevant requests in an effort to disrupt it fully or partially. This worst practice blocks the legitimate user requests from being processed. We explored an intelligent intrusion detection system (IIDS) using a particular sort of machine learning, such as Artificial Neural Networks, (ANN) in order to handle and mitigate this type of cyber-attacks. In this research paper Feed-Forward Neural Network (FNN) is tested for detecting the DDOS attacks using a modified version of the KDD Cup 99 dataset. The aim of this paper is to determine the performance of the most effective and efficient Back-propagation algorithms among several algorithms and check the potential capability of ANN- based network model as a classifier to counteract the cyber-attacks in IoT environments. We have found that except Gradient Descent with Momentum Algorithm, the success rate obtained by the other three optimized and effective Back- Propagation algorithms is above 99.00%. The experimental findings showed that the accuracy rate of the proposed method using ANN is satisfactory.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.1
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• pp.31-49
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• 2021

IoT devices refer to embedded devices that can communicate with networks. Since there are various types of IoT devices and they are widely used around us, in the event of an attack, damages such as personal information leakage can occur depending on the type of device. While the security team analyzes IoT devices, they should target firmware as well as software interfaces since IoT devices are operated by both of them. However, the problem is that it is not easy to extract and analyze firmware and that it is not easy to manage product quality at a certain level even if the same target is analyzed according to the analyst's expertise within the security team. Therefore, in this paper, we intend to establish a vulnerability analysis process for the firmware of IoT devices and present available tools for each step. Besides, we organized the process from firmware acquisition to analysis of IoT devices produced by various commercial manufacturers, and we wanted to prove their validity by applying it directly to drone analysis by various manufacturers.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.737-746
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• 2017

In 2017, amid changes in the security market such as integrated security (IS) and convergence security (CS), a variety of security paradigms in terms of operation and management have been suggested. Rather than changing existing network infrastructure and bringing about fluid, multi-dimensional changes, these solutions and technologies focus entire security capacity on a primary protection, leading to network infrastructure suffering from unexpected inherent violations and problems in a continued manner. Therefore, it is time to propose and develop a flexible network section that can protect from attacks of similar pattern and concentrated traffic attacks by applying a new concept of WB (Water-Bubble) to network infrastructure and analyzing on the basis of experiment and installation. Methodology of the WB-based highly secure flexible network section proposed in this study is expected to provide materials for studies on how to achieve network section security taking into account three major limitations and security standards: fluidity, unpredictability, and non-area scalability by contact point ratio, by changing a network area predicted to be the final target of attack into resonant network section (area) with flexible area changes.

• Journal of Advanced Navigation Technology
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• v.17 no.1
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• pp.123-131
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• 2013

If Industrial state-of-the-art technology that made through IT convergence should be to build safely environment that can protect then IT technology and manufacturing industry become convergence and a growth engine become stable positioning. In each industry, there has been a steady effort for the industrial security. However, they introduced only managerial/technical/physical countermeasures. Therefore, it is difficult to find a reference point as industrial security necessity, protecting coverage and things and so on. It is to lack that academic research in industrial security for protecting industrial technology. In detail, a clear definition lack for industrial security. And target range classification lack for industrial security studies. In this study, we redefined the concept of industry security through previous studies. Academic classification designed industrial security studies through delphi method. we analyzed industry security trends based industrial security studies classification and presented domestic industry research orientations.

• Nuclear Engineering and Technology
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• v.45 no.5
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• pp.637-652
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• 2013

Instrumentation and control systems in nuclear power plants have been digitalized for the purpose of maintenance and precise operation. This digitalization, however, brings out issues related to cyber security. In the most recent past, international standard organizations, regulatory institutes, and research institutes have performed a number of studies addressing these systems cyber security.. In order to provide information helpful to the system designers in their application of cyber security for the systems, this paper presents methods and considerations to define attack vectors in a target system, to review and select the requirements in the Regulatory Guide 5.71, and to integrate the results to identify applicable technical security control requirements. In this study, attack vectors are analyzed through the vulnerability analyses and penetration tests with a simplified safety system, and the elements of critical digital assets acting as attack vectors are identified. Among the security control requirements listed in Appendices B and C to Regulatory Guide 5.71, those that should be implemented into the systems are selected and classified in groups of technical security control requirements using the results of the attack vector analysis. For the attack vector elements of critical digital assets, all the technical security control requirements are evaluated to determine whether they are applicable and effective, and considerations in this evaluation are also discussed. The technical security control requirements in three important categories of access control, monitoring and logging, and encryption are derived and grouped according to the elements of attack vectors as results for the sample safety system.