• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4A
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• pp.466-471
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• 2004

This paper proposes an advanced circuit for fingerprint sensor signal processing. We increased the voltage between ridge and valley by modifying the parasitic capacitance eliminating circuit of sensor plate. The analog comparator was designed for comparing the sensor signal voltage with the reference signal voltage. 1-Pixel Fingerprint sensor circuit was designed and simulated, and the layout was performed.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.6
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• pp.63-71
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• 2006

In this paper, we propose a secure solution for user authentication by using fingerprint verification on the sensor-client-server model, even with the client that is not necessarily trusted by the sensor holder or the server. To protect possible attacks launched at the untrusted client, our solution makes the fingerprint sensor validate the result computed by the client for the feature extraction. However, the validation should be simple so that the resource-constrained fingerprint sensor can validate it in real-time. To solve this problem, we separate the feature extraction into binarization and minutiae extraction, and assign the time-consuming binarization to the client. After receiving the result of binarization from the client, the sensor conducts a simple validation to check the result, performs the minutiae extraction with the received binary image from the client, and then sends the extracted minutiae to the server. Based on the experimental results, the proposed solution for fingerprint verification can be performed on the sensor-client-server model securely and in real-time with the aid of an untrusted client.

• Review of KIISC
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• v.12 no.2
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• pp.25-33
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• 2002

지문인식 센서는 광학방식, 열방식, 반도체방식 등 다양한 입력 방식이 존재하며, 입력 방식에 따라 이미지의 특성이 다르게 나타난다. 특히 입력 방식의 차이는 알고리즘으로부터 정확한 결과를 도출하는데 중요한 역할을 한다. 따라서 다양한 입력 방식에 따른 센서들의 특징과 여러 조건하에서의 센서들의 이미지 품질을 비교해 보고 지문이미지로부터 특징점을 추출하고 매칭하는 과정에 대한 이해와 다양한 알고리즘의 특징등을 비교, 분석하여 발전방향에 대한 동향을 살펴본다.

• Journal of Korea Multimedia Society
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• v.13 no.9
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• pp.1337-1347
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• 2010

Fingerprint recognition is a biometric technology to identify individual by using fingerprint features such ridges and valleys. Most fingerprint systems perform the recognition based on minutiae points after acquiring a fingerprint image from contact type sensor. They have an advantage of acquiring a clear image of uniform size by touching finger on the sensor. However, they have the problems of the image quality can be reduced in case of severely dry or wet finger due to the variations of touching pressure and latent fingerprint on the sensor. To solve these problems, the contactless capturing devices for a fingerprint image was introduced in previous works. However, the accuracy of detecting minutiae points and recognition performance are reduced due to the degradation of image quality by the illumination variation. So, this paper proposes a new LDP-based fingerprint recognition method. It can effectively extract fingerprint patterns of iterative ridges and valleys. After producing histograms of the binary codes which are extracted by the LDP method, chi square distance between the enrolled and input feature histograms is calculated. The calculated chi square distance is used as the score of fingerprint recognition. As the experimental results, the EER of the proposed approach is reduced by 0.521% in comparison with that of the previous LBP-based fingerprint recognition approach.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10b
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• pp.526-528
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• 2000

일반적으로 지문 인식 알고리즘을 구현하기 위해서 전처리와 후처리를 거쳐 정합과 등록 등의 일률적인 과정을 거치게 된다. 하지만 사람의 지문은 개인의 생체학적 특성에 따라 많은 차이를 보인다. 본 논문에서는 두 가지 목적을 위하여 연구되었는데 첫 번째는 획득된 지문영상의 특성을 최대한 이용한 적응성 알고리즘의 개발이다. 보통 획득된 지문영상의 경우 좋은 품질의 영상과 손가락이 건조한 사람의 흐린 영상, 그리고 손가락이 젖은 사람에게서 나타나는 진한 영상 등의 크게 나누어 3가지로 나누어 볼 수 있는데 하나의 알고리즘을 통한 처리보다는 각 지문영상에서 적당한 알고리즘을 적용하는 것이 더욱 좋은 결과를 얻게 된다. 두 번째로 라인센서에서 얻은 낮은 품질의 영상을 처리하기 위한 알고리즘을 제안한다. 라인센서의 사용으로 인한 장점을 최대한 이용하여 지문인식 시스템을 개발하기 위한 목적을 갖는다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1297-1303
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• 2003

This paper propose an advanced circuit for fingerprint sensor signal processing. We increased the voltage between ridge and valley by modifying the parasitic capacitance eliminating circuit of sensor plate. The analog comparator was designed for comparing the sensor signal voltage with the reference signal voltage. We also propose an effective isolation strategy for removing noise and signal coupling, ESD of each sensor pixel. The 128${\times}$l44 pixel fingerprint sensor circuit was designed and simulated, and the layout was performed.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.458-460
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• 2020

최근 여러 IoT 기기 사용이 급증하면서 보안 위협요소가 사회적인 문제로 대두되고 있다. 이러한 IoT 기기에서 사용자 생체정보를 활용해 사용자를 인증하는 시스템은 보편적으로 사용되고 있다. 그 중 지문인식은 스마트폰부터 여러 기기에 탑재되어 있다. 본 논문에서는 지문인식 센서에 온도, 압력, 터치 센서를 추가하는 기법과 군집화, 패턴 학습 알고리즘을 적용하여 위 변조 검출 능력을 향상시키는 방법을 통하여 지문인식에 대한 이상 징후 탐지 방법을 제안하고자 한다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.3
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• pp.93-100
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• 2004

This paper presents a method to integrate the multiple impressions of a finger for improving fingerprint verification performance. Small-sized sensor has advantage that it can be used in many application fields. However, sufficiently large impression of fingerprint is not available due to the small sensing area, and this degrades the verification performance of the system. The proposed method overcomes this problem by combining the information of fingerprints for enrollment. To combine the fingerprints, the alignment process is important first of all. In the proposed algorithm multiple impressions of a finger are coarsely aligned using the corresponding minutiae pairs and then are finely aligned using the Distance Map. We construct an integrated template for enrollment in aligned coordinate system Since this integrated template represents the enlarged finger region, the problem that is occurred by using small sensor can be overcome. Experimental results show that the use of the integrated template of multiple impressions improves the performance of the fingerprint verification system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.249-252
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• 2003

This paper propose an advanced circuit for fingerprint sensor signal processing. We increased the voltage between ridge and valley by modifying the parasitic capacitance eliminating circuit of sensor plate. The analog to comparator was designed for comparing the sensor signal voltage with the reference signal voltage. We also propose an exective isolation strategy for removing noise and signal coupling of each sensor pixel. The 128$\times$144 pixel fingerprint sensor circuit was designed and simulated, and the layout was performed.

• Journal of Korea Multimedia Society
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• v.9 no.10
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• pp.1304-1313
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• 2006

Biometric-based authentication can provide strong security guarantee about the identity of users. However, security of biometric data is particularly important as the compromise of the data will be permanent. In this paper, we propose a secure and efficient protocol to transmit fingerprint images from a fingerprint sensor to a client by exploiting characteristics of fingerprint images. Because the fingerprint sensor is computationally limited, however, such encryption algorithm may not be applied to the full fingerprint images in real-time. To reduce the computational workload on the resource-constrained sensor, we apply the encryption algorithm to a specific bitplane of each pixel of the fingerprint image. We use the LSB as specific bitplane instead of MSB used to encrypt general multimedia contents because simple attacks can reveal the fingerprint ridge information even from the MSB-based encryption. Based on the experimental results, our proposed algorithm can reduce the execution time of the full encryption by a factor of six and guarantee both the integrity and the confidentiality without any leakage of the ridge information.