• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.196-201
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• 2016

Digital watermarking is a technique used to hide information within digital media. Digital watermarking techniques can be classified as either robust watermarking or fragile watermarking. Robust watermarking techniques are generally used for the purpose of copyright protection. In addition, fragile watermarking techniques are used for the authentication and integrity verification of a digital image. Therefore, fragile watermarks should be easily breakable for trivial tampering of a watermarked image. This paper proposes an efficient fragile watermarking method for image tamper detection in the spatial domain. In the proposed method, a hash code and symmetric key encryption algorithm are used. The proposed method of inserting a watermark by dividing the original image into many blocks of small sizes is not weak against attacks, such as cut and paste. The proposed method can detect the manipulated parts of a watermarked image without testing the entire block of the image.

• The KIPS Transactions:PartB
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• v.17B no.4
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• pp.275-286
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• 2010

Reversible watermarking which can preserve the original quality of the digital contents and protect the copyright has been studied actively. Especially, in medical, military, and art fields, the need for reversible watermarking is increasing. This paper proposes a high-capacity reversible watermarking through predicted error expansion and error estimation compensation. Watermark is embedded by expanding the difference histogram between the original value and the predicted value. Differently from previous methods calculating the difference between adjacent pixels, the presented method calculates the difference between the original value and the predicted value, and that increases the number of the histogram value, where the watermark is embedded. As a result, the high capacity is achieved. The inserted watermark is extracted by restoring the histogram between the original value and the predicted value. To prove the performance, the presented algorithm is compared with other previous methods on various test images. The result supports that the presented algorithm has a perfect reversibility, a high image quality, and a high capacity.

• International Commerce and Information Review
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• v.12 no.3
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• pp.55-78
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• 2010

This study analyses recent development of digital contents industry. The purpose of this study is to show how the convergence phenomenon is occurring in the digital contents industry. Furthermore, this study examines the influence of digital convergence on the digital contents industry. The characteristics of the digital contents industry falls roughly into three features. To begin with, technical aspect of the industrial feature is that digitalized contents can be used in various digital devices, namely OSMU(One Source Multi Use). The second feature is related to protection of copyright against illegal file sharing and downloading. One final point is that platform for distribution channels has been universal by digital convergence. To sum up, the notable feature of digital contents industry is high value-added. Also, digital contents industry is composed of users, digital device, network, and universal contents. Users are the key component of digital contents industry, who is distinguished from consumers. Digital devices such as mobile phone, PDA can play all kinds of digital contents and make users communicate in two-ways. Portable devices also allow the users to consume digital contents at any place. Digital contents can be distributed by both wire and wireless networks. And most of transactions can be made through networks. There are three key issues about digital convergence. Entry barriers for market become lowered; the age of contents users is changed from old generation to young generation. And the form of contents devices is changing rapidly. Traditional contents field such as movie, music, broadcasting, publishing, animations are combined into one digital contents territory. As a result, this paper suggests that digital convergence phenomenon will be accelerating for the future. According to the result of this study, the advent of digital convergence and e-Commerce will have significant influence on trade of digital contents.

• Journal of the Korea Convergence Society
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• v.2 no.1
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• pp.1-6
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• 2011

The wide use of mobile devices such as smart phones makes the mobile commerce industry be growing-up rapidly. In mobile commerce security, how to secure a copyright of mobile contents and how to distribute it are of major concerns. The user can carry the smart phone regardless of the places. Thus the utilization of it is very high than that of personal computers. The USIM(Universal Subscriber Information Module) inserted in the smart phone binds the user with the device. This means that the smart phone can be used to represent the owner's identity. In this paper, we develop the mobile ID based digital signature scheme. We create the mobile ID by combining USIM with the user's random secret value. In addition, undeniable property of our signature scheme can make ID based applications such as mobile voting and mobile content distribution be possible with the smart phone.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1224-1228
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• 2003

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 needs. Digital watermarking, the invisible encryption technique to insert digital watermarking 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 Institute of Electronics Engineers of Korea CI
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• v.46 no.1
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• pp.96-102
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• 2009

Due to the rapid growth of the Internet, it is possible to distribute the digital content efficiently. However, the need for image data protection and secret communication technique is also on the rise because of an infringement of the copyright by malicious attackers. Shamir and Lin-Tsai proposed simple secret image encryption algorithms based on the principle of secret sharing, respectively. However, their secret sharing schemes have a serious problem which can be declined the image quality and it is possible for third party to know embed information. In this paper, we propose a new secret sharing scheme using gray code that can be increased the image quality and security. As a result of our experiment, the proposed scheme is not only shown of good image quality and but also provide enhanced security compare with Shamir and Lin-Tasi's schemes.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.74-79
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• 2008

In this paper, we propose and design a new 0.264/AVC watermarking algorithm for protection of copyright by inserting a watermark after quantization. This invisible watermarking algorithm insets a watermark into chrominance components of I frame such that we can avoid degradation of original images. According to test results we could limit image degradation by 1dB, avoid bit rate increment within 2% and increase processing time by only 2%. The IP is designed by Hynix 0.25 micron technology and the maximum operating frequency of 115MHz is achieved. The PSNR of the embedded watermark is about 35dB according to the test result.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.68-73
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• 2008

In this paper, we propose watermark algorithm called TDWA(Time-Division Watermarking Algorithm) and we applied the proposed algorithm to H.264 video coding standard. We establish that a proposed algorithm is applied to H.264 baseline profile CODEC. The proposed algorithm inserts a watermark into the spatial domain of several frames. We can easily insert strong and invisible watermarks into original pictures using this method. For verification of the proposed algorithm we design hardware core using Verilog-HDL and Excalibur for JM 8.7 code with hardware & software co-simulation. As a result of verification, the PSNR between watermarked pictures and original pictures are more than 60dB and we found the watermark is kept more than 80% after encoding of H.264/AVC with quantization parameter of 28 in baseline profile.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.4
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• pp.113-123
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• 2004

This paper presents a new collusion-secure fingerprinting scheme to embed fingerprints into three-dimensional(3-D) mesh models efficiently. In the proposed scheme, we make the same number of fingerprints as the number of customers based on the finite projective geometry, partition a 3-D mesh model related to the number of bits assigned to each fingerprint and then embed a watermark representing copyright information into each submesh to be marked. Considering imperceptibility and robustness of the watermarking algorithm we embed the watermark signal into mid-frequency DCT coefficients obtained by transforming vertex coordinates in the triangle strips which are generated from the submeshes to be marked. Experimental results show that our scheme is robust to additive random noises, MPEG-4 SNHC 3-D mesh coding, geometrical transformations, and fingerprint attacks by two traitors' collusion. In addition, we can reduce the number of bits assigned to each fingerprint significantly.

• Spatial Information Research
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• v.21 no.3
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• pp.31-43
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• 2013

Although the vector map data possesses much higher values than other types of multimedia, the data copyright and the protection against illegal duplication are still far away from the attention. This paper proposes a novel watermarking technique which is both robust to diverse attacks and optimized to a vector map structure. Six approaches are proposed for the design of the watermarking algorithm: point-based approach, building a minimum perimeter triangle, watermark embedding in the length ratio, referencing to the pixel position of the watermark image, grouping, and using the one-way function. Our method preserves the characteristics of watermarking such as embedding effectiveness, fidelity, and false positive rate, while maintaining robustness to all types of attack except a noise attack. Furthermore, our method is a blind scheme in which robustness is independent of the map data. Finally, our method provides a solution to the challenging issue of degraded robustness under severe simplification attacks.