• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.4
• /
• pp.99-105
• /
• 2015

As increasing the use of smart phones, the interest of iOS and Android operating system is growing up. In this paper, a novel steganographic method based on Android platform is proposed. Firstly, we analyze the skia based image format that is supporting 2D graphic libraries in Android operating system. Then, we propose a new data hiding method based on the Android bitmap image format. The proposed method hides the secret data on the four true color areas which include Alpha, Red, Green, Blue. In especial, we increase the embedding capacity of the secret data on the Alpha area with a less image distortion. The experimental results show that the proposed method has a higher embedding capacity and less distortion by changing the size of the secret bits on the Alpha area.

• Journal of Korea Society of Industrial Information Systems
• /
• v.20 no.3
• /
• pp.29-36
• /
• 2015

Steganography is the technique of hiding the existence of a secret message that is communicated hiddenly. Generally, the main objectives of this paper is to develop newer and more sophisticated steganographic techniques based on perceptual transparency, robustness and capacity of the hidden data. This paper analyzes the advantages and disadvantages of image steganography techniques and proposes an effective method. As a result, the images steganography technique based on good ELSB and DCT which applies the rearranged key is secure and effective.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.2
• /
• pp.268-274
• /
• 2010

A steganographic method using three directional data embedding for gray images is presented in this paper. Cover image is divided into non-overlapping $2\times2$ sub-blocks and the basis pixel is selected to calculate the three different values of each sub-block. Difference values are replaced by embedding the number of secret bits that is referenced by the range table. For the three pixel pairs in the sub-block, the optimal pixel adjustment is preceded to reduce the distortion of visual quality. The experimental results show that the proposed method achieves a good visual quality and high capacity.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.11 no.3
• /
• pp.115-122
• /
• 2008

Wu and Tsai's pixel-value differencing method and Chang and Tseng's side-match method are based on the theory that the number of bits which can be embedded is determined by the degree of the pixel's smoothness, or its proximity to the edge of the image. If pixels are located in the edge area, they may tolerate larger changes than those in smooth areas. However, both methods are subject to the fall off the boundary problem(FOBP). This study proposes a new scheme that can solve the FOBP. The experimental results demonstrate that the proposed method resolves the problem, and achieves a higher image quality index value than other methods.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2018.07a
• /
• pp.478-479
• /
• 2018

본 논문에서는 NTFS 파일시스템에서 디렉토리 인덱스의 구조내에 데이터를 숨기기 방법을 적용하는데 있어서 필요한 요소들에 대한 설명과 그것의 필요성에 대하여 논하기로 한다. 기존에 발표된 이 방법은 NTFS의 디렉토리 인덱스를 유지하기 위하여 B-tree방식으로 인덱스에 대한 데이터 구조를 운영하고 있는 점을 이용하여 인덱스의 정보를 담고 있는 인덱스 레코드 안에 저장되는 파일명을 이용하여 데이터 감추기를 수행하는 방법이다. 이것을 하기 위하여 필요한 몇가지 요소가 있는데 그 중에서 파일시스템, 작업 디렉토리, 위장 파일, 숨기려는 데이터, 사용할 수 없는 문자들, 앵커파일, 분석도구 등에 대한 것들을 나열하고 해당하는 요소들이 필요성과 그에 대한 의미를 기술하고자 한다.

• ETRI Journal
• /
• v.37 no.5
• /
• pp.990-1000
• /
• 2015

This paper presents an overlapping pattern substitution (PS) method. The original overlapping PS method as a reversible data hiding scheme works well with only four pattern pairs among fifteen possible such pairs. This paper generalizes the original PS method so that it will work well with an optimal pair from among the fifteen possible pattern pairs. To implement such an overlapping PS method, changeable and embeddable patterns are first defined. A class map is virtually constructed to identify the changeable and embeddable pairs. The run-lengths between consecutive least probable patterns are recorded. Experiments show that an implementation of our overlapping PS method works well with any possible type of pairs. Comparison results show that the proposed method achieves more embedding capacity, a higher PSNR value, and less human visual distortion for a given embedding payload.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2020.01a
• /
• pp.65-66
• /
• 2020

이 논문에서는 NTFS 파일시스템에서 여러 개의 클러스터에 걸쳐서 슬랙 영역에 데이터 숨기기를 수행하는 데이터 숨기기 방법의 강인성을 조사하기 위하여 디스크 조각모음 실험을 수행할 때 필요한 방법을 제안한다. 디스크 조각모음의 실행으로 클러스터의 위치가 변동되기 위해서는 여러 클러스터에 걸친 디스크 조각의 단편화가 일어날 수 있도록 파일을 생성하고 삭제하는 작업을 수행한다. 그 후에 용량이 큰 파일을 복사하여 여러 클러스터에 걸친 단편화된 파일을 작위적으로 생성한다. 단편화된 파일만을 남기고 그 이외의 다른 파일들을 삭제한 후에 디스크조각 모음을 수행한다. 이 실험에 필요한 준비과정과 실험과정을 제안한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2006.11a
• /
• pp.317-320
• /
• 2006

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.8 no.4
• /
• pp.327-337
• /
• 2015

This work provides new forensic techinque to a hide message on a directory index in Windows NTFS file system. Behavior characteristics of B-tree, which is apoted to manage an index entry, is utilized for hiding message in slack space of an index record. For hidden message not to be exposured, we use a disguised file in order not to be left in a file name attribute of a MFT entry. To understand of key idea of the proposed technique, we describe B-tree indexing method and the proposed of this work. We show the proposed technique is practical for anti-forensic usage with a real message hiding case using a developed software tool.

• Journal of Korea Multimedia Society
• /
• v.14 no.10
• /
• pp.1323-1334
• /
• 2011

This paper suggests the border based HSFI algorithm to hide sensitive frequent itemsets. Node formation of FP-Tree which is different from the previous one uses the border to minimize the impacts of nonsensitive frequent itemsets in hiding process, including the organization of sensitive and border information, and all transaction as well. As a result of applying HSFI algorithms, it is possible to be the example transaction database, by significantly reducing the lost items, it turns out that HSFI algorithm is more effective than the existing algorithm for maintaining the quality of more improved database.