• ETRI Journal
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• 제41권6호
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• pp.739-749
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• 2019

Security and accuracy are two issues in the localization of wireless sensor networks (WSNs) that are difficult to balance in hostile indoor environments. Massive numbers of malicious positioning requests may cause the functional failure of an entire WSN. To eliminate the misjudgments caused by malicious nodes, we propose a compressive-sensing-based multiregional secure localization (CSMR_SL) algorithm to reduce the impact of malicious users on secure positioning by considering the resource-constrained nature of WSNs. In CSMR_SL, a multiregion offline mechanism is introduced to identify malicious nodes and a preprocessing procedure is adopted to weight and balance the contributions of anchor nodes. Simulation results show that CSMR_SL may significantly improve robustness against attacks and reduce the influence of indoor environments while maintaining sufficient accuracy levels.

• 융합보안논문지
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• 제23권5호
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• pp.101-106
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• 2023

최근 사이버 공격은 지능적이고 지속적인 피싱사이트와 악성코드를 활용한 해킹 기법을 활용하는 사회공학적 공격이 증가하고 있다. 개인 보안이 중요해지는 만큼 웹 어플리케이션을 이용해 악성 URL 여부를 판별하는 방법과 솔루션이 요구되고 있다. 본 논문은 악성 URL를 탐지하는 정확도가 높은 기법들을 비교하여 각각의 특징과 한계를 알아가고자 한다. 웹 평판 DB 등 기반 URL 탐지 사이트와 특징을 활용한 분류알고리즘 모델과 비교하여 효율적인 URL 이상탐지 기법을 제안하고자 한다.

• Journal of information and communication convergence engineering
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• 제15권2호
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• pp.91-96
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• 2017

PIN-entry interfaces have high risks to leak secret values if the malicious attackers perform shoulder-surfing attacks with advanced monitoring and observation devices. To make the PIN-entry secure, many studies have considered invisible radio channels as a secure medium to deliver private information. However, the methods are also vulnerable if the malicious adversaries find a hint of secret values from user's $na{\ddot{i}}ve$ gestures. In this paper, we revisit the state-of-art radio channel based bimodal PIN-entry method and analyze the information leakage from the previous method by exploiting the sight tracking attacks. The proposed sight tracking attack technique significantly reduces the original password complexities by 93.8% after post-processing. To keep the security level strong, we introduce the advanced bimodal PIN-entry technique. The new technique delivers the secret indicator information through a secure radio channel and the smartphone screen only displays the multiple indicator options without corresponding numbers. Afterwards, the users select the target value by following the circular layout. The method completely hides the password and is secure against the advanced shoulder-surfing attacks.

• Journal of Information Processing Systems
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• 제12권3호
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• pp.422-435
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• 2016

Despite the convenience brought by the advances in web and Internet technology, users are increasingly being exposed to the danger of various types of cyber attacks. In particular, recent studies have shown that today's cyber attacks usually occur on the web via malware distribution and the stealing of personal information. A drive-by download is a kind of web-based attack for malware distribution. Researchers have proposed various methods for detecting a drive-by download attack effectively. However, existing methods have limitations against recent evasion techniques, including JavaScript obfuscation, hiding, and dynamic code evaluation. In this paper, we propose an emulation-based malicious webpage detection method. Based on our study on the limitations of the existing methods and the state-of-the-art evasion techniques, we will introduce four features that can detect malware distribution networks and we applied them to the proposed method. Our performance evaluation using a URL scan engine provided by VirusTotal shows that the proposed method detects malicious webpages more precisely than existing solutions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권12호
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• pp.3244-3260
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• 2013

A three-party password-based authenticated key exchange (PAKE) protocol allows two clients registered with a trusted server to generate a common cryptographic key from their individual passwords shared only with the server. A key requirement for three-party PAKE protocols is to prevent an adversary from mounting a dictionary attack. This requirement must be met even when the adversary is a malicious (registered) client who can set up normal protocol sessions with other clients. This work revisits three existing three-party PAKE protocols, namely, Guo et al.'s (2008) protocol, Huang's (2009) protocol, and Lee and Hwang's (2010) protocol, and demonstrates that these protocols are not secure against offline and/or (undetectable) online dictionary attacks in the presence of a malicious client. The offline dictionary attack we present against Guo et al.'s protocol also applies to other similar protocols including Lee and Hwang's protocol. We conclude with some suggestions on how to design a three-party PAKE protocol that is resistant against dictionary attacks.

• 융합보안논문지
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• 제7권4호
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• pp.123-131
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• 2007

최근 각종 보안 침해 사고는 불특정 다수를 대상으로 발생하고 있으며, 이는 네트워크를 통한 정보의 공유가 가속화되면서 그 피해가 더욱 늘어나고 있다. 이러한 보안 침해 사고는 침입차단시스템, 침입탐지시스템, 가상사설망 등 정보보호시스템의 활용으로 최소화가 가능하지만, 이는 전문가적인 지식이 필요하며 일반 사용자가 운영하기가 쉽지 않다. 본 논문에서는 일반 사용자가 쉽게 사용할 수 있도록 파일 접근 제어 모듈을 설계 및 개발하였고, 이는 공격에 대한 탐지가 아닌 운영체제상에서 공격에 대한 차단할 수 있다. 본 논문에서 구현한 파일 접근 제어 모듈은 윈도우환경 뿐만 아니라 리눅스 환경에서도 적용할 수 있으며, 다중 사용자가 사용하는 운영체제에 따라 파일에 대한 접근 제어를 함으로써 파일에 대한 접근제어, 무결성, 부인 방지를 할 수 있다.

• Journal of Information Processing Systems
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• 제14권1호
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• pp.56-78
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• 2018

Security issue in mobile ad hoc network (MANET) is a promising research. In 2011, we had accomplished a survey of black hole attacks in MANETs. However network technology is changing with each passing day, a vast number of novel schemes and papers have been proposed and published in recent years. In this paper, we survey the literature on malicious attacks in MANETs published during past 5 years, especially the black hole attack. Black hole attacks are classified into non-cooperative and collaborative black hole attacks. Except black hole attacks, other attacks in MANET are also studied, e.g., wormhole and flooding attacks. In addition, we conceive the open issues and future trends of black hole detection and prevention in MANETs based on the survey results of this paper. We summarize these detection schemes with three systematic comparison tables of non-cooperative black hole, collaborative black hole and other attacks, respectively, for a comprehensive survey of attacks in MANETs.

• International Journal of Computer Science & Network Security
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• 제21권6호
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• pp.89-100
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• 2021

Smart Grid Network (SGN) is a next generation electrical power network which digitizes the power distribution grid and achieves smart, efficient, safe and secure operations of the electricity. The backbone of the SGN is information communication technology that enables the SGN to get full control of network station monitoring and analysis. In any network where communication is involved security is essential. It has been observed from several recent incidents that an adversary causes an interruption to the operation of the networks which lead to the electricity theft. In order to reduce the number of electricity theft cases, companies need to develop preventive and protective methods to minimize the losses from this issue. In this paper, we have introduced a machine learning based SVM method that detects malicious nodes in a smart grid network. The algorithm collects data (electricity consumption/electric bill) from the nodes and compares it with previously obtained data. Support Vector Machine (SVM) classifies nodes into Normal or malicious nodes giving the statues of 1 for normal nodes and status of -1 for malicious -abnormal-nodes. Once the malicious nodes have been detected, we have done a trust evaluation based on the nodes history and recorded data. In the simulation, we have observed that our detection rate is almost 98% where the false alarm rate is only 2%. Moreover, a Trust value of 50 was achieved. As a future work, countermeasures based on the trust value will be developed to solve the problem remotely.

• Journal of information and communication convergence engineering
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• 제16권2호
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• pp.93-98
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• 2018

The Internet of Things (IoT) is a form of the emerging 4th industry in the 5G era. IoT is expected to develop naturally in our daily life in the 5G era in which high-speed communication will be completed. Along with the rise of IoT, concerns about security and malicious attacks are also increasing. This paper examines DoS attacks, which are one of the representative security threats of IoT and proposes a local detection and blocking system that are suitable for response to such attacks. First, systems of the LoRaWAN type, which are most actively researched in the IoT system field and DoS attacks that can occur in such systems were examined. Then, the inverse order tree algorithm using regional characteristics was designed as a cluster analysis form. Finally, a system capable of defending denial-of-service attacks in the 5G IoT system using local detection and blocking with the Euclidean distance was designed.

• 융합보안논문지
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• 제6권1호
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• pp.1-11
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• 2006

최근 사이버테러의 급증은 정보사회의 근간을 위협하고 있고, 특히 악성 트래픽에 의한 네트워크마비는 단 시간 내에 국가적인 손실을 초래할 수 있어 이에 대한 대비책이 시급히 요구되고 있다. 이와 관련, 국가사이버안전 위협에 대한 신속한 대처능력확보를 위해 국가사이버위협 조기 예 경보시스템에 대해 많은 연구가 이루어지고 있으나 기술적인 문제와 함께 시스템의 효용성에 대한 한계 때문에 실용적인 연구가 가시화되지 못하고 있는 실정이다. 현재까지는 ESM, TMS 등을 이용한 제한적 자료수집분석을 통하여 보안관리자가 개개인의 경험을 바탕으로 예 경보 판단을 내려왔다. 이러한 판단은 상황에 따라 극히 위험한 결과를 초래 할 수도 있다. 이러한 문제점을 방지하기 위해 본 논문에서는 "지식기반을 이용한 실시간 사이버위협 조기 예 경보시스템"을 제안하였다. 제안된 시스템은 향후 사이버공격에 대해 체계적이고 보다 정확한 예 경보 판단을 내리는데 사용할 수 있다.