• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.309-316
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• 2024

Facial recognition technology is widely used in various fields but faces challenges due to its vulnerability to fraudulent activities such as photo spoofing. Extensive research has been conducted to overcome this challenge. Most of them, however, require the use of specialized equipment like multi-modal cameras or operation in high-performance environments. In this paper, we introduce LH-FAS v2 (: Lightweight Head-pose-based Face Anti-Spoofing v2), a system designed to operate on a commercial webcam without any specialized equipment, to address the issue of facial recognition spoofing. LH-FAS v2 utilizes FSA-Net for head pose estimation and ArcFace for facial recognition, effectively assessing changes in head pose and verifying facial identity. We developed the VD4PS dataset, incorporating photo spoofing scenarios to evaluate the model's performance. The experimental results show the model's balanced accuracy and speed, indicating that head pose estimation-based facial anti-spoofing technology can be effectively used to counteract photo spoofing.

• Survey Research
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• v.8 no.2
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• pp.21-42
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• 2007

In the present study, we studied the change patterns of adolescents' overt aggression during the middle school 2nd to the high school 1st grades and the effects of ecological factors on the change. For the research goals, we applied multi-level models to the Korean Youth Panel data. Results showed that adolescents' overt aggression decreased significantly during the period. Gender(males recoded as 1) and self-control had negative effects on the initial status(middle school 2nd grade) while the number of delinquency peers had a positive effect. On the other hand, gender and self-control showed positive effects on the change rate. The major strengths of the research are the study of various ecological factors and the longitudinal design. Few studies of adolescents' aggression have incorporated these methodological and substantive characteristics.

• Journal of Internet Computing and Services
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• v.17 no.2
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• pp.19-28
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• 2016

Internet traffic has been significantly increasing due to the development of information and communication networks and the growing numbers of cell phone users that access networks. This paper connects to this issue by presenting a way to detect and analyze a typical DDoS attack that results in Internet breaches and network attacks, which are on the increase. To achieve this goal, we improve features and GUI of the existing ATMSim analysis package and use it. This package operates on a network flow-based analysis method, which means that normal traffic collected through an internal LAN at the Korean Bible University campus as well as anomaly traffic with DDoS attacks are generated. Self-similarity processes are used to analyze normal and anomaly traffic that are collected and generated from the improved ATMSim. Our numerical results obtained from three Hurst parameter estimate techniques show that there is quantitatively a significant difference between normal traffic and anomaly traffic from a self-similarity perspective.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.337-339
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• 2013

최근 국내에서는 북한의 사이버 테러로 추정되는 전산망 해킹(APT공격)사건과 더불어 하나의 전자전으로서 GPS 재밍 사건들이 인천 등 서해에서 다수 발생되어 왔다. 즉, 이러한 GPS 재머는 러시아 등에서 유출되는 간단한 장비에서부터 치명적인 대규모 전파공격까지 다양한 형태가 발생될 수 있다. 특히 GPS 정보를 사용하는 선박의 AIS 정보는 다수의 선박으로부터 전송되는 정보로서 재밍 대응 가능한 고가의 장비를 선박측에서 탑재하기 어려우며, 송신지가 인근 북한의 경우 국내에서 근원지를 탐지하더라도 대응이 어려운 실정이다. 따라서 본 논문에서는 GPS 교란의 지능화된 여러 공격 형태를 파악하고, 해상교통관제 시스템에서 자체적으로 실시간 대응할 수 있는 방안을 검토하여 시스템 설계에 반영 하고, 관제사의 실시간 인지를 통한 혼란을 방지하며, 선박에 해당 교란 정보를 제공함으로서 능동적인 관제 방안을 제시한다. 실제적으로 재밍에 대응하는 시스템 설계가 관제에 효율적인 방안인지 확인되어야 하며, 국가적으로도 VTS 서비스의 안전성을 보장하는 기술개발로 진화가 고려되어야 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.29-32
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• 2023

양자 컴퓨터의 연산 성능이 알려지면서 기존 암호 시스템이 붕괴될 것이라 예상한다. 앞선 많은 연구들은 공격 대상 암호에 대해 양자회로로 구현하고 공격에 필요한 양자자원을 추정하였지만 암호를 공격하기 위해서는 대규모 양자컴퓨터의 동작을 요구한다. 뿐만 아니라 내결함성 양자 컴퓨터에서 유효한 결과를 얻기 위해서는 오류 정정이 필수적이며 오류 정정에도 양자 자원을 소비하며 결과적으로 더 큰 규모의 양자컴퓨터가 필요하고 크기가 커질수록 오류가 증가한다. 이러한 내결함성 대규모 양자회로에서 T 게이트를 구현하는 것이 다른 게이트를 구현하는 것 보다 어렵고 T-depth가 회로의 실행시간에 큰 영향을 미친다. 본 논문에서는 T-depth 최적화 도구 및 T-depth 감소 기법을 적용한 방식을 조사하였다.

• The KIPS Transactions:PartC
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• v.18C no.1
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• pp.7-14
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• 2011

Power analysis attack on low-power consumed security devices such as smart cards is very powerful, but it is required that the correlation between the measured power signal and the mid-term estimated signal should be consistent in a time instant while running encryption algorithm. The power signals measured from the security device applying the random clock do not match the timing point of analysis, therefore random clock is used as counter measures against power analysis attacks. This paper propose a new constant pitch based time alignment for power analysis with random clock power trace. The proposed method neutralize the effects of random clock used to counter measure by aligning the irregular power signals with the time location and size using the constant pitch. Finally, we apply the proposed one to AES algorithm within randomly clocked environments to evaluate our method.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.731-734
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• 2001

본 논문에서는 2단계 참조를 통하여 원본 워터마크에 보다 근접한 워터마크를 추정해내는 워터마킹 방법을 제안한다. 이 방법은 워터마크 추출시 원본 영상을 필요로 하지 않으며 워터마크는 이진 신호가 된다. 여기서 참조 워터마크는 워터마크의 왜곡 정도를 알려주는데 이것을 가지고 좀 더 정확한 워터마크를 추정 해낼 수 있게 된다. 본 논문에서는 또한 추출된 워터마크와 원본 워터마크를 비교할 때 좀 더 정확한 비교를 위해서 국부 상관성을 이용한 방법을 제안한다. 실험 결과 공격의 특성에 구애받지 않고 일정한 성능을 보여줌을 확인 할 수 있었다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.4
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• pp.111-121
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• 2004

With rapid growth of the Internet, network intrusions have greatly increased and damage of attacks has become more serious. Recently some kinds of Internet attacks cause significant damage to overall network performance. Current Intrusion Detection Systems are not capable of performing the real-time detection on the backbone network In this paper, we propose the broadband network intrusion detection system using the exponential smoothing method. We made an experiment with real backbone traffic data for 8 days. The results show that our proposed system detects big jumps of traffic volume well.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.05a
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• pp.183-186
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• 2022

고성능 양자 컴퓨터가 개발될 것으로 기대됨에 따라 잠재적인 양자 컴퓨터의 공격으로부터 안전한 양자 후 보안 시스템을 구축하기 위한 연구들이 진행되고 있다. 대표적인 양자 알고리즘인 Grover 알고리즘이 대칭키 암호에 적용될 경우 보안 강도가 제곱근으로 감소되는 보안 훼손이 발생한다. NIST는 대칭키 암호에 대한 양자 후 보안 요구사항으로, 암호 알고리즘 공격에 요구되는 Grover 알고리즘 비용을 기준을 기준으로 양자 후 보안 강도를 추정하고 있다. 대칭키 암호를 공격하기 위한 Grover 알고리즘의 비용은 대상 암호화 알고리즘의 양자 회로 복잡도에 따라 결정된다. 본 논문에서는 NIST 경량암호 공모전 최종 후보에 오른 Sparkle 알고리즘의 양자 회로를 효율적으로 구현하고 Grover 알고리즘을 적용하기 위한 양자 비용에 대해 분석한다. 마지막으로, NIST 양자 후 보안 요구사항과 분석한 비용을 기반으로 경량암호 Sparkle에 대한 양자 후 보안 강도를 평가한다. 양자 회로 구현 및 비용 분석에는 양자 프로그래밍 툴인 ProjectQ가 사용되었다.

• Journal of the Korean Data and Information Science Society
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• v.23 no.5
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• pp.993-1003
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• 2012

The purpose of this study was to estimate the determinants of victory and defeat through analyzing records of Korean men pro-basketball. Statistical models of victory and defeat were established by collecting present basketball records (2010-2011, 2011-2012 season). Korea Basketball League (KBL) informs records of every pro-basketball game data. The six offence variables (2P%, 3P%, FT%, OR, AS, TO), and the four defense variables (DR, ST, GD, BS) were used in this study. PASW program was used for logistic regression and Answer Tree program was used for the decision tree. All significance levels were set at .05. Major results were as follows. In the logistic regression, 2P%, 3P%, and TO were three offense variables significantly affecting victory and defeat, and DR, ST, and BS were three significant defense variables. Offensive variables 2P%, 3P%, TO, and AS are used in constructing the decision tree. The highest percentage of victory was 80.85% when 2P% was in 51%-58%, 3P% was more than 31 percent, and TO was less than 11 times. In the decision tree of the defence variables, the highest percentage of victory was 94.12% when DR was more than 24, ST was more than six, and BS was more than two times.