• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.343-352
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• 2008

Safety-critical systems related to the railway communications are currently undergoing changes. Mechanical and electro-mechanical devices are being replaced by programmable electronics that are often controlled remotely via communication networks. Therefore designers and operators now not only have to contend with component failures and user errors, but also with the possibility that malicious entities are seeking to disrupt the services provided by theirs systems. Recognizing the safety-critical nature of the types of communications required in rail control operations, the communications infrastructure will be required to meet a number of safety requirements such as system faults, user errors and the robustness in the presence of malicious attackers who are willing to take determined action to interfere in the correct operation of a system. This paper discusses the safety strategies employed in the railway communications and proposes a security mechanism for Korean railway communication system. We present the developed communication safety evaluation tool based on the proposed security mechanism and also evaluate its protecting capability against the threats of masquerading, eavesdropping, and unauthorized message manipulation.

• 중소기업융합학회논문지
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• 제6권1호
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• pp.17-23
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• 2016

최근에 스마트 폰을 비롯한 다양한 단말기를 통한 인터넷 서비스가 가능해졌다. ICT 발달로 인해 기업과 공공기관에서 크고 작은 해킹사고가 발생하는데 그 공격의 대부분은 APT공격으로 밝혀졌다. APT공격은 공격의 목적을 달성하기 위해 지속적으로 정보를 수집하고, 장기간 동안 공격대상의 취약점을 분석하거나 악성코드를 다양한 방법으로 감염시키고, 잠복하고 있다가 적절한 시기에 자료를 유출하는 공격이다. 본 논문에서는 APT 공격자가 짧은 시간에 타겟 시스템에 침입하기 위해 빅데이터 기술을 이용하는 정보 수집 기법을 살펴보고 빅데이터를 이용한 공격기법을 보다 효율적으로 방어할 수 있는 기법을 제안하고 평가한다.

• Journal of information and communication convergence engineering
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• 제8권4호
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• pp.427-432
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• 2010

The fast-emerging of cloud computing technology today has sufficiently benefited its wide range of users from individuals to large organizations. It carries an attractive characteristic by renting myriad virtual storages, computing resources and platform for users to manipulate their data or utilize the processing resources conveniently over Internet without the need to know the exact underlying infrastructure which is resided remotely at cloud servers. However due to the loss of direct control over the systems/applications, users are concerned about the risks of cloud services if it is truly secured. In the literature, there are cases where attackers masquerade as cloud users, illegally access to their accounts, by stealing the static login password or breaking the poor authentication gate. In this paper, we propose a two-factor authentication framework to enforce cloud services' authentication process, which are Public Key Infrastructure (PKI) authentication and mobile out-of-band (OOB) authentication. We discuss the framework's security analysis in later session and conclude that it is robust to phishing and replay attacks, prohibiting fraud users from accessing to the cloud services.

• Journal of Information Processing Systems
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• 제7권1호
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• pp.121-136
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• 2011

With the rapid growth of GPS-enable Smartphones, the interest on using Location Based Services (LBSs) has increased significantly. The evolution in the functionalities provided by those smartphones has enabled them to accurately pinpoint the location of a user. Because location information is what all LBSs depend on to process user's request, it should be properly protected from attackers or malicious service providers (SP). Additionally, maintaining user's privacy and confidentiality are imperative challenges to be overcome. A possible solution for these challenges is to provide user anonymity, which means to ensure that a user initiating a request to the SP should be indistinguishable from a group of people by any adversary who had access to the request. Most of the proposals that maintain user's anonymity are based on location obfuscation. It mainly focuses on adjusting the resolution of the user's location information. In this paper, we present a new protocol that is focused on using cryptographic techniques to provide anonymity for LBSs users in the smartphone environment. This protocol makes use of a trusted third party called the Anonymity Server (AS) that ensures anonymous communication between the user and the service provider.

• ETRI Journal
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• 제33권6호
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• pp.935-944
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• 2011

As a growing number of individuals are exposed to surveillance cameras, the need to prevent captured videos from being used inappropriately has increased. Privacy-related information can be protected through video encryption during transmission or storage, and several algorithms have been proposed for such purposes. However, the simple way of evaluating the security by counting the number of brute-force trials is not proper for measuring the security of video encryption algorithms, considering that attackers can devise specially crafted attacks for specific purposes by exploiting the characteristics of the target video codec. In this paper, we introduce a new attack for recovering contour information from encrypted H.264 video. The attack can thus be used to extract face outlines for the purpose of personal identification. We analyze the security of previous video encryption schemes against the proposed attack and show that the security of these schemes is lower than expected in terms of privacy protection. To enhance security, an advanced block shuffling method is proposed, an analysis of which shows that it is more secure than the previous method and can be an improvement against the proposed attack.

• 한국통신학회논문지
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• 제38B권7호
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• pp.526-534
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• 2013

최근 다양한 형태의 클라우드 컴퓨팅 서비스의 출현으로 인한 가상화 기술이 급부상 하면서 데이터에 대한 안전성과 신뢰성 등 보안 문제가 이슈화되고 있다. 클라우드 서비스의 가상화 계층의 손상은 모든 호스트(사용자) 업무의 손상을 가져올 수 있기 때문에 복수의 가상 운영체제가 구동될 수 있는 환경을 제공하는 하이퍼바이저는 해커들에 의해 공격 대상이 될 수 있다. 본 논문에서는 가상화 기술인 하이퍼바이저(베어 메탈 기반)에 해킹 및 악성코드에 예방을 위한 보안 구조를 제안한다.

• Journal of Communications and Networks
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• 제15권2호
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• pp.122-131
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• 2013

We address the problem of effective vehicular routing in hostile scenarios where malicious nodes intend to jeopardize the delivery of messages. Compromised vehicles can severely affect the performance of the network by a number of attacks, such as selectively dropping messages, manipulating them on the fly, and the likes. One of the best performing solutions that has been used in static wireless sensor networks to deal with these attacks is based on the concept of watchdog nodes (also known as guard nodes) that collaborate to continue the forwarding of data packets in case a malicious behavior in a neighbor node is detected. In this work, we consider the beacon-less routing algorithm for vehicular environments routing protocol, which has been previously shown to perform very well in vehicular networks, and analyze whether a similar solution would be feasible for vehicular environments. Our simulation results in an urban scenario show that watchdog nodes are able to avoid up to a 50% of packet drops across different network densities and for different number of attackers, without introducing a significant increase in terms of control overhead. However, the overall performance of the routing protocol is still far from optimal. Thus, in the case of vehicular networks, watchdog nodes alone are not able to completely alleviate these security threats.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1307-1313
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• 2017

Sensor networks are composed of provide low powered, inexpensive distributed devices which can be deployed over enormous physical spaces. Coordination between sensor devices is required to achieve a common communication. In low cost, low power and short-range wireless environment, sensor networks cope with significant resource constraints. Security is one of main issues in wireless sensor networks because of potential adversaries. Several security protocols and models have been implemented for communication on computing devices but deployment these models and protocols into the sensor networks is not easy because of the resource constraints mentioned. Memory intensive encryption algorithms as well as high volume of packet transmission cannot be applied to sensor devices due to its low computational speed and memory. Deployment of sensor networks without security mechanism makes sensor nodes vulnerable to potential attacks. Therefore, attackers compromise the network to accept malicious sensor nodes as legitimate nodes. This paper provides the different security models as a metric, which can then be used to make pertinent security decisions for securing wireless sensor network communication.

• 정보보호학회논문지
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• 제27권6호
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• pp.1457-1465
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• 2017

스마트기기 시장의 성장과 함께 모바일 환경에서 악성행위가 그 영역을 점차 확대하고 있다. 이에 따라 악성앱 분석에 대한 연구가 진행되어 앱 분석을 위한 자동 분석 도구가 나오면서, 오히려 이런 자동 분석도구들로 인해 기존의 앱 보안을 위한 도구들이 공격자에게 무력해지는 부작용이 일어난다. 본 논문은 일반적인 안드로이드 앱에 적용할 수 있는 범용적인 보호 기법이 아닌 보안 토큰을 가진 스마트 기기 사용자가 이용하는 안드로이드 앱에 적용할 수 있는 앱 보호 기법에 대해 제안한다. 보안 토큰이 삽입되지 않은 경우 앱이 정상적으로 메모리로 적재되지 못하며, 해당 기법으로 보호된 부분은 노출되지 않도록 하는 것을 특징으로 한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.281-284
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• 2010

해외로부터의 Hacking의 특징은 추적 기법을 동원 하더라도 공격자 Real IP 주소를 찾을 수 없기 때문에 수사에 어려움이 큰 것이 현실이다. 이는 공격자가 Proxy Server를 여러 번 거치면서 자신의 IP 주소를 숨기는 IP Spoofing 기법을 사용하기 때문이다. 본 논문에서는 공격자들이 어떻게 IP Spoofing 기법을 이용하고, Proxy Server를 응용하여 공격을 시도하는지를 연구한다. 또한 Proxy Server를 통한 IP Spoofing 공격 및 방어하는 방법과 IP 역추적 방법을 제안하여 본 연구의 자료가 국제적인 Hacking과 보안방어 기술 발전에 기여 할 것이다.