• Journal of Positioning, Navigation, and Timing
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• 제9권3호
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• pp.215-220
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• 2020

This paper deal with estimating the direction of arrival (DOA) of GNSS signal using two antennae for spoofing detection. A technique for estimating the azimuth angle of a received signal by applying the interferometer method to the GPS carrier signal is proposed. The experiment assumes two antennas placed on the earth's surface and estimates the azimuth angle when only GPS signal are received without spoofing signal. The proposed method confirmed the availability through GPS satellite placement simulation and experiments using a dual antenna GPS receiver. In this case of using dual antenna, an azimuth angle ambiguity of the received signal occurs with respect to the baseline between two antennas. For this reason, the accurate azimuth angle estimation is limits, but it can be used for deception by cross-validating the ambiguity.

• Journal of Positioning, Navigation, and Timing
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• 제7권3호
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• pp.139-146
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• 2018

In recent years, a satellite navigation signal authentication technique has been introduced to determine the spoofing of commercial C/A code using the cross-correlation mode of GPS P(Y) code received at two receivers. This paper discusses the technical considerations in the implementation and application of authentication system simulator hardware to achieve the above technique. The configuration of the simulator consists of authentication system and user receiver. The synchronization of GPS signals received at two devices, data transmission and reception, and codeless correlation of P(Y) code were implemented. The simulation test result verified that spoofing detection using P(Y) codeless correlation could be achieved.

• 한국통신학회논문지
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• 제32권2B호
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• pp.118-123
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• 2007

This paper studied the transmission control protocol over IP network to enhance the performance of the GSO satellite communication networks. The focus of this study is how to reduce the long round trip time and the transmission data rates over satellite link in the bidirectional satellite network. To do it, this study applied the caching and spoofing technology. The spoofing technology is used to reduce the required time for the link connection during communication. The caching technology is to improve the transmission bandwidth efficiency in the high transmission data rate link The tests and measurements in this study was performed in the commercial GSO communication satellite network and the terrestrial Internet network. The results of this paper show that the studied protocol in this paper highly enhance the performance of the bidirectional satellite communication network compare to the using TCP/IP satellite network protocol.

• International Journal of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.187-194
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• 2021

This paper presents a margin-based face liveness detection method with behavioral confirmation to prevent spoofing attacks using deep learning techniques. The proposed method provides a possibility to prevent biometric person authentication systems from replay and printed spoofing attacks. For this work, a set of real face images and fake face images was collected and a face liveness detection model is trained on the constructed dataset. Traditional face liveness detection methods exploit the face image covering only the face regions of the human head image. However, outside of this region of interest (ROI) might include useful features such as phone edges and fingers. The proposed face liveness detection method was experimentally tested on the author's own dataset. Collected databases are trained and experimental results show that the trained model distinguishes real face images and fake images correctly.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 춘계학술발표대회
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• pp.1482-1485
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• 2009

DDoS 공격은 네트워크 보안에 큰 피해를 미치는 공격기법의 하나로써, 국내외로 많은 피해를 유발하고 있으며, 최근에도 DDoS 공격에 의한 피해는 빈번하게 보고되고 있다. DDoS 공격은 실제 공격에 앞서 웜과 악성 BOT을 이용하여 공격을 직접 수행할 호스트를 감염시킨다. 웜과 악성 BOT이 타깃 호스트를 감염시키기 전에 반드시 수행하는 것이 취약점에 대한 스캐닝이다. 본 논문에서는 웜과 악성 BOT의 스캐닝 행위에 초점을 맞추어 DDoS 공격으로부터 안전한 네트워크를 구축하기 위한 역 IP spoofing을 이용한 DDoS 웜 스캐닝 트래픽의 처리기법을 제안한다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2021년도 추계학술발표대회
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• pp.651-654
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• 2021

Face anti-spoofing (FAS) techniques play a significant role in the defense of facial recognition systems against spoofing attacks. Existing FAS methods achieve the great performance depending on annotated additional modalities. However, labeling these high-cost modalities need a lot of manpower, device resources and time. In this work, we proposed to use self-transforming modalities instead the annotated modalities. Three different modalities based on frequency domain and temporal domain are applied and analyzed. Intuitive visualization analysis shows the advantages of each modality. Comprehensive experiments in both the CNN-based and transformer-based architecture with various modalities combination demonstrate that self-transforming modalities improve the vanilla network a lot. The codes are available at https://github.com/chenmou0410/FAS-Challenge2021.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2010년도 한국컴퓨터종합학술대회논문집 Vol.37 No.1(A)
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• pp.7-8
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• 2010

• 융합보안논문지
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• 제16권7호
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• pp.21-29
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• 2016

현재 우리사회는 네트워크를 통하여 실시간으로 교류되는 다양한 정보 환경에 노출되어 있다. 특히 정부의 의료정책은 대국민의료서비스 질을 향상시키기 위해 원격진료의 시행을 서두르고 있다. 이러한 원격진료의 시행은 향후 지역에 상관없이 맞춤형 환자 진료를 위한 빅 데이터 기반의 진료 정보 구축도 함께 요구하고 있다. 본 논문은 빅 데이터 기반의 권역별 의료클러스터 구축과 이에 대한 서비스 가용성을 해치는 공격이 발생할 경우 해당 공격을 탐지하고 적절한 대응이 가능한 방어 및 보안 협력모델을 제안하고 있다. 이를 위하여 동일 병원정보시스템으로 전국에 고루 분포된 지방의료원을 권역별 가상 의료클러스터 본부로 하는 네트워크 구성을 제안하였다. 아울러 의료클러스터에 발생할 수 있는 IP Spoofing 공격과 이에 따른 DDoS 공격에 실시간으로 대응 가능한 상호협력 보안 모델을 설계하여 단일 체계, 단일 보안정책이 가지는 한계성도 극복할 수 있도록 하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권5호
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• pp.1726-1743
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• 2014

DDoS (Distributed Denial of Service) has been a continuous threat to the cyber world with the growth in cyber technology. This technical evolution has given rise to a number of ultra-sophisticated ways for the attackers to perform their DDoS attack. In general, the attackers who generate the denial of service, use the vulnerabilities of the TCP. Some of the vulnerabilities like SYN (synchronization) flooding, and IP spoofing are used by the attacker to create these Distributed Reflected Denial of Service (DrDoS) attacks. An attacker, with the assistance of IP spoofing creates a number of attack packets, which reflects the flooded packets to an attacker's intended victim system, known as the primary target. The proposed scheme, Efficient Spoofed Flooding Defense (ESFD) provides two level checks which, consist of probing and non-repudiation, before allocating a service to the clients. The probing is used to determine the availability of the requested client. Non-repudiation is taken care of by the timestamp enabled in the packet, which is our major contribution. The real time experimental results showed the efficiency of our proposed ESFD scheme, by increasing the performance of the CPU up to 40%, the memory up to 52% and the network bandwidth up to 67%. This proves the fact that the proposed ESFD scheme is fast and efficient, negating the impact on the network, victim and primary target.

• 방송공학회논문지
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• 제24권6호
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• pp.1113-1121
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• 2019

본 논문에서는 얼굴의 밝기와 색상 정보를 함께 이용한 합성곱 신경망 기반의 얼굴 위변조 검출 방법을 제안한다. 제안하는 방법은 적층된 합성곱 신경망과 보조 신경망을 이용하여 실제 얼굴과 위변조된 얼굴의 밝기 특징과 색상 특징을 독립적으로 추출한다. 기존의 방법과는 달리, 본 논문에서는 추출된 특징을 단순 결합(Concatenation)하는 것이 아니라 주의 모듈(Attention Module)을 이용하여 적응적(Adaptively)으로 조합할 수 있도록 하였다. 또한, 효과적인 분류기 학습을 위하여 대비 손실함수(Contrast Loss Function)를 새롭게 제안하였는데, 대비 손실함수는 동일 클래스 내의 특징 간의 차이는 최소화 시키고 서로 다른 클래스의 특징 간의 차이는 최대화 시킴으로써 특징의 분별력을 높인다. 다양한 실험을 통해 본 논문에서 제안하는 방법이 기존 얼굴 위변조 검출 방법 대비 개선된 성능을 보임을 확인하고 그 결과를 분석한다.