• 한국멀티미디어학회논문지
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• 제20권1호
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• pp.74-81
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• 2017

In learning stage of the preliminary Cut-off indoor positioning scheme, RSSI and UUID data received from beacons at each reference point(RP) are stored in fingerprint map. The fingerprint map and real-time beacon information are compared to identify the nearest K reference points through which the user position is estimated. If the number of K is zero, this scheme cannot estimate user position. We have improved the preliminary Cut-off scheme to get the estimated user position even in the case. The improved scheme excludes the beacon of the weakest signal received by user mobile device and identifies neighborhood reference points using the other beacon information. This procedure are performed repetitively until K > 0. The simulation results confirm that the proposed scheme outperforms K-Nearest-Neighbor (KNN), Cluster KNN and the conventional Cut-off scheme in terms of accuracy while the constraints are guaranteed to be satisfied.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권10호
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• pp.1783-1798
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• 2011

Recently, a cryptographic construct, called fuzzy vault, has been proposed for crypto-biometric systems, and some implementations for fingerprint have been reported to protect the stored fingerprint template by hiding the fingerprint features. In this paper, we implement the fuzzy fingerprint vault, combining fingerprint verification and fuzzy vault scheme to protect fingerprint templates. To implement the fuzzy fingerprint vault as a complete system, we have to consider several practical issues such as automatic fingerprint alignment, verification accuracy, execution time, error correcting code, etc. In addition, to protect the fuzzy fingerprint vault from the correlation attack, we propose an approach to insert chaffs in a structured way such that distinguishing the fingerprint minutiae and the chaff points obtained from two applications is computationally hard. Based on the experimental results, we confirm that the proposed approach provides higher security than inserting chaffs randomly without a significant degradation of the verification accuracy, and our implementation can be used for real applications.

• Journal of Information Processing Systems
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• 제19권6호
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• pp.756-766
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• 2023

To effectively track the illegal use of digital images and maintain the security of digital image communication on the Internet, this paper proposes a reversible multipurpose image watermarking algorithm based on a deep residual network (ResNet) and perceptual hashing (also called MWR). The algorithm first combines perceptual image hashing to generate a digital fingerprint that depends on the user's identity information and image characteristics. Then it embeds the removable visible watermark and digital fingerprint in two different regions of the orthogonal separation of the image. The embedding strength of the digital fingerprint is computed using ResNet. Because of the embedding of the removable visible watermark, the conflict between the copyright notice and the user's browsing is balanced. Moreover, image authentication and traitor tracking are realized through digital fingerprint insertion. The experiments show that the scheme has good visual transparency and watermark visibility. The use of chaotic mapping in the visible watermark insertion process enhances the security of the multipurpose watermark scheme, and unauthorized users without correct keys cannot effectively remove the visible watermark.

• 제어로봇시스템학회논문지
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• 제18권9호
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• pp.801-805
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• 2012

This paper proposes dynamic thresholding scheme for fingerprint identification. As a user authentication method by fingerprint recognition technology, verification method based on 1:1 matching was mainly used in the past, but identification method based on 1:N matching is generally used recently. The control of the value of FAR is very important in the application areas such as access control and time attendance systems. This paper proposes dynamic thresholding scheme which could properly control the value of FAR according to the field of applications and size of the fingerprints database.

• 한국정보과학회논문지:시스템및이론
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• 제34권7호
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• pp.288-295
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• 2007

디지털 형식으로 저장되어 있는 데이타의 불법적인 복사와 재분배는 전자상거래 상에서 디지털 콘텐츠를 판매하는 판매자에게 매우 큰 문제가 된다. 핑거프린팅 기법은 암호학적인 기법들을 이용하여 디지털 콘텐츠를 불법적으로 재배포한 구매자를 찾아냄으로써 저작자의 저작권을 보호한다. 익명적 비대칭적 핑거프린팅 기법은 대칭적인 기법과 달리 구매자만이 핑거프린트가 삽입된 콘텐츠를 알 수 있어 구매자가 콘텐츠를 재배포했을 경우만 구매자가 고발되며, 데이타가 재배포되기 전에는 구매자의 익명성이 보장되는 기법이다. 본 논문에서는 신뢰기관을 이용한 익명적 비대칭 핑거프린팅 기법을 제안한다. 이 기법에서는 구매자의 핑거프린트는 신뢰기관인 핑거프린트 인증센터에서 생성한다. 또한, 판매자가 핑거프린트를 삽입할 때, 준동형의 암호를 이용하여 콘텐츠에 삽입함으로써 판매자는 구매자의 핑거프린트를 알 수 없으며 익명 공개키를 이용함으로써 구매자의 익명성을 보장하였다.

• 센서학회지
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• 제14권1호
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• pp.28-32
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• 2005

In this paper, a CMOS integrated detection circuit for capacitive type fingerprint sensor signal processing is described. We designed a detection circuit of charge-sharing sensing scheme. The proposed detection circuit increases the voltage difference between a ridge and valley. The test chip is composed of $160{\times}192$ array sensing cells (12 by $12.7{\;}mm^{2}$). The chip was fabricated on a 0.35 m standard CMOS process. Measured difference voltage between a ridge and valley was 0.95 V.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.427-428
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• 2006

This paper presents an image fingerprinting scheme for the print-to-capture model performed by a photo printer and digital camera. When capturing an image by a digital camera, various kinds of distortions such as noise, geometrical distortions, and lens distortions are applied. slightly and simultaneously. In this paper, we consider several steps to extract fingerprints from the distorted image in print-and capture scenario. To embed ID into an image as a fingerprint, multi-bits embedding is applied. We embed 64 bits information as a fingerprint into spatial domain of color images. In order to restore a captured image from distortions a noise reduction filter is performed and a rectilinear tiling pattern is used as a template. To make the template, a multi-bits fingerprint is embedded repeatedly like a tiling pattern. We show that the extracting is successful from the image captured by a digital camera through the experiment.

• 전자공학회논문지CI
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• 제43권5호
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• pp.68-75
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• 2006

멀티미디어 핑거프린팅은 각각의 유저에게 배포되어지는 디지털 콘텐츠마다 고유한 정보를 가지게 만듦으로써 불법적으로 콘텐츠를 배포하는 사용자로부터 멀티미디어 콘텐츠를 보호한다. 또한, 핑거프린팅 기법은 대칭적이나 비대칭적인 기법과 달리 사용자만이 핑거프리트가 삽입된 데이터를 알 수 있고 데이터가 재배포되기 전에는 사용자의 익명성이 보장되는 기법이다. 본 논문에서는 공모자 검출과 에러 신호의 정정을 위하여 LDPC(Low Density Parity Check) 알고리즘을 이용한 멀티미디어 핑거프린트의 검출 알고리즘을 제안한다. 제안된 알고리즘은 LDPC 블록, 홉필드 망, 그리고 불법공모방지코드 생성 알고리즘으로 구성되어 있다. BIBD(Balanced Incomplete Block Design) 기반의 불법공모방지코드는 평균화 선형 공모공격(평균, AND, OR)에 대해 100% 공모코드 검출이 이루어졌으며, LDPC 블럭은 AWGN 0dB까지 에러비트를 정정할 수 있음을 확인하였다.

• 정보보호학회논문지
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• 제27권6호
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• pp.1361-1372
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• 2017

비공개 애플리케이션 또는 핑거프린팅 기법이 적용된 애플리케이션을 외부의 공격자가 복사해 가져가는 경우 비공개 정보가 유출되거나 정당한 사용자가 애플리케이션의 불법 재배포자로 오인될 수 있어 심각한 보안 문제가 초래될 수 있다. 이러한 문제를 해결하기 위하여 본 논문에서는 지문 인증과 동적 로딩을 이용한 안드로이드 애플리케이션 코드 보호 기법을 제안한다. 본 논문에서 제안하는 기법은 하나의 애플리케이션을 CLR(Class LoadeR)과 SED(SEperated Dex)로 구성한다. CLR은 SED를 동적으로 로드하는 기능을 가진 APK 파일이며, SED는 애플리케이션 실행에 필요한 클래스들이 포함된 파일이다. SED는 암호화된 상태로 스마트폰 내부에 보관되며, 사용자는 지문 인증을 성공한 경우에만 SED를 복호화할 수 있다. 본 논문에서 제안하는 기법은 사용자의 스마트폰을 물리적으로 획득한 공격자로부터 애플리케이션 코드를 안전하게 보호할 수 있다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제11권4호
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• pp.286-292
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• 2011

Biometrics systems are used in a wide range of areas, including the area of crime prevention, due to their unique characteristics. However, serious problems can occur if biometric information is disclosed to an unauthorized user. To address these issues, this paper proposes a real valued fuzzy vault method, which adopts a real number error correction code to implement a fuzzy vault scheme for protecting fingerprint temples. The proposed method provides the benefit of allowing the private key value to be changed at any time, unlike biometric template such as a fingerprint, which is not easily renewable even if its security has been breached. The validity of the proposed method is verified for fingerprint verification.