• 한국인터넷방송통신학회논문지
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• 제14권6호
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• pp.281-288
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• 2014

QR 코드는 바코드보다 수백 배 많은 양의 데이터를 인코딩할 수 있도록 기능을 향상시킨 코드체계로서 이미지 훼손에 강하다. 이러한 이유로 QR 코드는 최근에 다양한 분야에서 사용되고 있다. 예를 들어 항공권 티켓 (보딩 통제 시스템), 푸드 (야채, 육류 이력) 추적 시스템, 콘택트렌즈 관리, 처방전 관리, 환자 손목밴드 (환자관리) 등에 사용된다. 본 논문에서는 이진 이미지에 대한 가역적인 데이터은닉 방법을 제안한다. 가역적인 데이터 은닉방법은 스테고 이미지로부터 데이터를 추출한 후 원본 이미지를 복원할 수 있기 때문에서 다양한 목적으로 활용될 수 있다. QR 코드는 누구나 코드를 생성할 수 있으므로 위조된 QR 코드를 이용하여 범죄에 사용할 수 있다. 본 논문에서는 이를 방지하기 위해서 이진 QR 코드 이미지에 인증 데이터를 은닉하여 위조여부를 확인할 수 있도록 하였다. 본 논문에서는 제안한 방법은 실험을 통해서 입증을 하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권4호
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• pp.1248-1266
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• 2012

This paper presents a multilevel reversible data hiding method based on histogram shifting which can recover the original image losslessly after the hidden data has been extracted from the stego-image. The method of prediction is adopted in our proposed scheme and prediction errors are produced to explore the similarity of neighboring pixels. In this article, we propose two different predictors to generate the prediction errors, where the prediction is carried out using the center prediction method and the JPEG-LS median edge predictor (MED) to exploit the correlation among the neighboring pixels. Instead of the original image, these prediction errors are used to hide the secret information. Moreover, we also present an improved method to search for peak and zero pairs and also talk about the analogy of the same to improve the histogram shifting method for huge embedding capacity and high peak signal-to-noise ratio (PSNR). In the one-level hiding, our method keeps image qualities larger than 53 dB and the ratio of embedding capacity has 0.43 bpp (bit per pixel). Besides, the concept with multiple layer embedding procedure is applied for obtaining high capacity, and the performance is demonstrated in the experimental results. From our experimental results and analytical reasoning, it shows that the proposed scheme has higher PSNR and high data embedding capacity than that of other reversible data hiding methods presented in the literature.

• 한국멀티미디어학회논문지
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• 제19권9호
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• pp.1669-1678
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• 2016

There are many kinds of military images used in naval combat system because various sensors are operated. The military images are displayed, analysed and stored with analysed informations according to the tactical purpose on combat system. These images are used to target detection, analysis and classification. Thus the analysed information and images must be secured, the information hiding methods are the most eligible solutions to get secured informations and images. In this paper, the hybrid information hiding method based on the characteristics of the military images is proposed and the effectiveness is shown by experiments.

• ETRI Journal
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• 제42권3호
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• pp.446-458
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• 2020

In this study, an efficient scheme for hiding data directly in partially encrypted versions of high efficiency video coding (HEVC) videos is proposed. The content owner uses stream cipher to selectively encrypt some HEVC-CABAC bin strings in a format-compliant manner. Then, the data hider embeds the secret message into the encrypted HEVC videos using the specific coefficient modification technique. Consequently, it can be used in third-party computing environments (more generally, cloud computing). For security and privacy purposes, service providers cannot access the visual content of the host video. As the coefficient is only slightly modified, the quality of the decrypted video is satisfactory. The encrypted and marked bitstreams meet the requirements of format compatibility, and have the same bit rate. At the receiving end, data extraction can be performed in the encrypted domain or decrypted domain that can be adapted to different application scenarios. Several standard video sequences with different resolutions and contents have been used for experimental evaluation.

• 디지털콘텐츠학회 논문지
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• 제17권6호
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• pp.461-469
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• 2016

본 논문에서는 t = 2인 3진 BCH 코드를 기반으로 하는 새로운 스테가노그라피 방법을 제시한다. 제안 된 방법에서는 JPEG 영상으로부터 추출된 DCT 계수들에 데이터 은닉을 하기 위해 t = 2인 강력한 BCH 코드를 사용하였다. 제안하는 데이터 은닉 기술은 삼진 BCH 코드(t=2인 경우)에서 다양한 해결책을 찾기 위한 접근으로 제안된 룩업테이블을 사용하였다. 고안된 룩업 테이블 접근법은 데이터 은닉을 위해 수정이 필요한 DCT 계수들의 위치를 빠르고 효율적으로 연산 가능하게 하였다. 제시된 데이터 은닉 기술은 삼진 BCH 코드를 이용하는 최초의 스테가노그라피 기술이다. 실험 결과를 통해 이진 BCH 코드에 비해 삼진 BCH 코드를 사용하는 것이 우수함을 명확하게 증명하였다.

• Journal of Electrical Engineering and Technology
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• 제11권4호
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• pp.974-986
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• 2016

Reversible image watermarking, a type of digital data hiding, is capable of recovering the original image and extracting the hidden message with precision. A number of reversible algorithms have been proposed to achieve a high embedding capacity and a low distortion. While numerous algorithms for the achievement of a favorable performance regarding a small embedding capacity exist, the main goal of this paper is the achievement of a more favorable performance regarding a larger embedding capacity and a lower distortion. This paper therefore proposes a reversible data hiding algorithm for which a novel piecewise 2D auto-regression (P2AR) predictor that is based on a rhombus-embedding scheme is used. In addition, a minimum description length (MDL) approach is applied to remove the outlier pixels from a training set so that the effect of a multiple linear regression can be maximized. The experiment results demonstrate that the performance of the proposed method is superior to those of previous methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권9호
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• pp.3286-3301
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• 2014

Jung and Yoo proposed the first image interpolation-based reversible data hiding algorithm. Although their algorithm achieved superior interpolation results, the embedding capacity was insufficient. Lee and Huang proposed an improved algorithm to enhance the embedding capacity and the interpolation results. However, these algorithms present limitations to magnify the original image to any resolution and pixels in the boundary region of the magnified image are poorly manipulated. Furthermore, the capacity and the image quality can be improved further. This study modifies the pixel mapping scheme and adopts a bilinear interpolation to solve boundary artifacts. The modified reference pixel determination and an optimal pixel adjustment process can effectively enhance the embedding capacity and the image quality. The experimental results show our proposed algorithm achieves a higher embedding capacity under acceptable visual distortions, and can be applied to a magnified image at any resolution. Our proposed technique is feasible in reversible data hiding.

• 아태비즈니스연구
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• 제13권1호
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• pp.19-36
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• 2022

Purpose - Previous studies tried to find antecedents of innovative behavior. However, research on knowledge hiding behavior, psychological mechanism, and perception of organizational justice has been relatively limited. In this sense, this study has investigated the impact of organizational justice on employees' innovative behavior and explored the factors that affect the above relationship. Especially, this study tested the direct effect of organizational justice on innovative behavior. This study also examines the mediating roles of knowledge hiding behavior in this causal relationship. Moreover, the process of organizational justice to innovative behavior is assumed to be influenced by leadership style. Therefore, we examined the moderating effect of authentic leadership on the relationship between organizational justice and knowledge hiding behavior. Design/methodology/approach - For the empirical test, we collected data via a questionnaire survey of a sample of 252 employees from Korean firms. We conducted a hierarchical regression analysis to test hypotheses. Results - The results of the empirical analysis revealed that organizational justice was positively related to innovative behavior and negatively related to knowledge hiding behavior. The results also showed that knowledge hiding behavior negatively mediated the relationship between organizational justice and innovative behavior. In addition, we found the moderating role of authentic leadership. More importantly, we found that the conditional indirect effect of organizational justice on innovative behavior via knowledge hiding behavior was depending on authentic leadership. Uncovering the relationship between organizational justice and innovative behavior through the mediating role of knowledge hiding behavior and the moderated mediating role of authentic leadership has useful theoretical and practical implications. We also suggest directions for future research by providing several limitations.

• ETRI Journal
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• 제36권2호
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• pp.325-328
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• 2014

A modified version of Zhang's reversible data hiding method in encrypted images is proposed in this letter. To make full use of spatial correlation in natural images, the former idea of block division is thoroughly abandoned, whereas the random diffusion strategy is used. Additionally, the fluctuation measurement of pixels containing embedded data is improved by accurate prediction. The experiment results reveal that our proposed method is superior to both Zhang's method and the later improved version proposed by Hong and others.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권11호
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• pp.2913-2927
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• 2013

A data hiding scheme in HTML files is presented in this paper. Web pages are a very popular medium for broadcasting information and knowledge nowadays, and web pages are a good way to achieve the goal of secret message delivery because the different HTML coding codes will render the same screen in any of the popular browsers. The proposed method utilizes the HTML special space codes and sentence segmentation to conceal secret messages into a HTML file. The experimental results show that the stego HTML file generated by the proposed method is imperceptible. Also, the proposed method can conceal one more secret bit in every between-word location.