• Journal of the Optical Society of Korea
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• v.19 no.3
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• pp.241-247
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• 2015

The double-random phase encryption (DRPE) algorithm is a robust technique for image encryption, due to its high speed and encoding a primary image to stationary white noise. Recently it was reported that DRPE in the Fresnel domain can achieve a better avalanche effect than that in Fourier domain, which means DRPE in the Fresnel domain is much safer, to some extent. Consequently, a method based on DRPE in the Fresnel domain would be a good choice. In this paper we present an image-authentication method which uses only partial phase information from a double-random-phase-encrypted image in the Fresnel domain. In this method, only part of the phase information of an image encrypted with DRPE in the Fresnel domain needs to be kept, while other information like amplitude values can be eliminated. Then, with the correct phase keys (we do not consider wavelength and distance as keys here) and a nonlinear correlation algorithm, the encrypted image can be authenticated. Experimental results demonstrate that the encrypted images can be successfully authenticated with this partial phase plus nonlinear correlation technique.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4912-4917
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• 2015

Fragile watermarking is a technique to insert a watermark into an image without significantly degrading its visual quality so that the watermark can be extracted for the purposes of authentication or integrity verification. And the watermark for authentication and integrity verification should be erased easily when the image is changed by filtering etc. In this paper, we propose a image block-wise watermarking method for image tamper proofing using digital signature. In the proposed method, a digital signature is generated from the hash code of the initialized image block. And The proposed method is able to detect the tampered parts of the image without testing the entire block of the watermarked image.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.12
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• pp.100-108
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• 2002

This paper describes the development of adult authentication system using numerical recognition. Nowadays, the automats are very popular and they are dealing in many item suck as coffee, soft drinks, alcoholic drinks and cigarettes, etc. Among these items, some are harmful to the minor, and so the sale of these to the minor must be prohibited. In relation to this, adult authentication system is required to be equipped to the automat which deals in items harmful to minor. According to these demands, we develop the adult authentication system. This system capture the image of a residence certificate card by the identification card-reader, and recognize its numbers and identify it as adult or minor by main computer, where numeral recognition is accomplished by using image processing methods and neural network recognizer. The characteristic test of the system is carried out, and its result reveals that the system has the error of less than 1%. Thus, It is thought that the system can be used for identifying adult in the automats.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.4
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• pp.1-12
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• 2018

Currently, a large amount of printed matter associated with code authentication method are diffused widely, however, they have been reproduced with great precision and distributed successively in illegal ways. In this paper, we propose an efficient code authentication method which classifies authentic or counterfeit with smart-phone, effectively. The proposed method stores original image code in the server side and then extracts multiple comparison measures describing the original image. Based on these multiple measures, a code authentication algorithm is designed in such a way that counterfeit printed images may be effectively classified and then the recognition rate may be highly improved. Through real experiments, it is shown that the proposed method can improve the recognition rate greatly and lower the mis-recognition rate, compared with single measure method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.11
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• pp.2941-2956
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• 2013

In this paper, we propose an effective fragile image watermarking scheme for tampering detection and content recovery. Cover image is divided into a series of non-overlapping blocks and a block mapping relationship is constructed by the secret key. Several DCT coefficients with direct current and lower frequencies of the MSBs for each block are used to generate the reference bits, and different coefficients are assigned with different bit numbers for representation according to their importance. To enhance recovery performance, authentication bits are generated by the MSBs and the reference bits, respectively. After LSB substitution hiding, the embedded watermark bits in each block consist of the information of itself and its mapping blocks. On the receiver side, all blocks with tampered MSBs can be detected and recovered using the valid extracted reference bits. Experimental results demonstrate the effectiveness of the proposed scheme.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.24 no.4
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• pp.363-374
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• 2020

Fingerprint authentication identifies a user based on the individual's unique fingerprint features. Fingerprint authentication methods are used in various real-life devices because they are convenient and safe and there is no risk of leakage, loss, or oblivion. However, fingerprint authentication methods are often ineffective when there is contamination of the given image through wet, dirty, dry, or wounded fingers. In this paper, a method is proposed to remove noise from fingerprint images using a convolutional neural network. The proposed model was verified using the dataset from the ChaLearn LAP Inpainting Competition Track 3-Fingerprint Denoising and Inpainting, ECCV 2018. It was demonstrated that the model proposed in this paper obtains better results with respect to the methods that achieved high performances in the competition.

• International Journal of Contents
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• v.9 no.2
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• pp.14-21
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• 2013

Current smartphone authentication systems are deemed inconvenient and difficult for users on remembering their password as well as privacy issues on stolen or forged biometrics. New authentication system is demanded to be implicit to users with very minimum user involvement being. This idea aims towards a future model of authentication system for smartphones users without users realizing them being authenticated. We use the most frequent activity that users carry out with their smartphone, which is the calling activity. We derive two basics related interactions that are first factor being arm's flex (AF) action to pick a phone to be near ones' ears and then once getting near ear using second factor from ear shape image. Here, we combine behavior biometrics from AF in first factor and physical biometrics from ear image in second factor. Our study shows our dual-factor authentication system does not require explicit user interaction thereby improving convenience and alleviating burden from users from persistent necessity to remember password. These findings will augment development of novel implicit authentication system being transparent, easier, and unobtrusive for users.

• Journal of Information Processing Systems
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• v.13 no.2
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• pp.385-399
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• 2017

Nowadays, with the development of signal processing technique, the protection to the integrity and authenticity of images has become a topic of great concern. A blind image authentication technology with high tamper detection accuracy for different common attacks is urgently needed. In this paper, an improved fragile watermarking method based on local binary pattern (LBP) is presented for blind tamper location in images. In this method, a binary watermark is generated by LBP operator which is often utilized in face identification and texture analysis. In order to guarantee the safety of the proposed algorithm, Arnold transform and logistic map are used to scramble the authentication watermark. Then, the least significant bits (LSBs) of original pixels are substituted by the encrypted watermark. Since the authentication data is constructed from the image itself, no original image is needed in tamper detection. The LBP map of watermarked image is compared to the extracted authentication data to determine whether it is tampered or not. In comparison with other state-of-the-art schemes, various experiments prove that the proposed algorithm achieves better performance in forgery detection and location for baleful attacks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.937-942
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• 2002

The use of digital imaging technique and digital contents based on internet has grown rapidly for last several years, and the needs of digital image protection become more important. For the purpose of copyright protection on digital image, the verification of authentication techniques like content authentication, ownership authentication, illegal copy and etc are needed. Digital watermarking, the invisible encryption technique to insert digital watermark into image the sophisticated perceptual information should be used for providing transparency and robustness of images on watermarking process. In this paper, we implement the algorithm for preventing forged attack, ownership protection and authentication by transforming the wavelet algorithms in frequency domain in terms of human visual system.

• Journal of the Korea Society of Computer and Information
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• v.13 no.5
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• pp.263-272
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• 2008

The proposed system can achieve more safety of RFID system with the 2-step authentication procedures for the enhancement about the security of general RFID systems. After it has authenticated RFID tag, additionally, the proposed system extract the characteristic information in the user image for acquisition of the additional authentication information of the user with the camera. In this paper, the system which was proposed more enforce the security of the automatic entrance and exit authentication system with the cognitive characters of RFID tag and the extracted characteristic information of the user image through the camera. The RFID system which use the active tag and reader with 2.4GHz bandwidth can recognize the tag of RFID in the various output manner. Additionally, when the RFID system have errors. the characteristic information of the user image is designed to replace the RFID system as it compare with the similarity of the color, outline and input image information which was recorded to the database previously. In the experimental result, the system can acquire more exact results as compared with the single authentication system when it using RFID tag and the information of color characteristics.