Jongweon Kim

Watermarking two dimensional data object identifier for authenticated distribution of digital multimedia contents

A digital object identifier refers to diverse technologies associated with assigning an identifier to a digital resource and managing the identification system. One type of implementation of a digital object identifier developed by the Korean Government is termed the Universal Content Identifier (UCI) system. It circulates and utilizes identifiable resources efficiently by connecting various online and offline identifying schemes. UCI tags can contain not only identifiers but also abundant additional information regarding contents. So, researchers and practitioners have shown great interest in methods that utilize the two-dimensional barcode (2D barcode) to attach UCI tags to digital contents. However, attaching a 2D barcode directly to a digital content raises two problems. First, quality of the content may deteriorate due to the insertion of the barcode; second, a malicious user can invalidate the identifying tag, simply by removing the tag from the original content. We believe that these concerns can be mitigated by inserting an invisible digital tag containing information about an identifier and digital copyrights into the entire area of the digital content. In this study, to protect copyrights of digital contents securely without quality degradation, we attempt to discover a sequence of process for generating a 2D barcode from a UCI tag and watermarking the barcode into a digital content. Such a UCI system can be widely applied to areas such as e-learning, distribution tracking, transaction certification, and reference linking services when the system is equipped with 2D barcode technology and secure watermarking algorithms. The latter part of this paper analyzes intensive experiments conducted to evaluate the robustness of traditional digital watermarking algorithms against external attacks.

Securing E-Government Services

Widespread Internet access is making it possible for governments around the world to move information and services online, providing substantial savings in cost, time, and labor. By letting citizens interact with the government from their own computer rather than in person, e-government also enhances quality of service and accessibility. However, economy and convenience must be traded off against security. Online systems are vulnerable to hackers, and the government has an obligation to prevent the unauthorized disclosure of personal information as well as prevent forgery and alteration of official documents

Robust Blind Watermarking Scheme for Digital Images Based on Discrete Fractional Random Transform

This paper proposes a robust blind watermarking scheme for digital images based on discrete fractional random transform, a generalization of the discrete fractional Fourier transform with intrinsic randomness. The proposed watermarking scheme can be easily used to embed and extract a watermark and it provides strong information security because of its inherent randomness. Experimental results obtained by subjecting the watermark to several types of attacks reveal that it is robust against frequency and geometric attacks, thus verifying its effectiveness.

A Secure Image Watermarking Using Visual Cryptography

In this paper we proposed a secure image watermarking algorithm for digital image using the visual cryptography. The proposed algorithm operates in discrete cosine transform (DCT) and discrete fractional random transform (DFRNT) domain which is characterized by fractional order α and random seed β. In the watermark embedding process of the proposed algorithm some blocks of a cover object is selected randomly, and they are transformed to DFRNT domain. The watermark is generated by the visual cryptography and embedded into the DCT coefficient of the DFRNTed block. The watermark extraction process is the reverse process of embedding process. The proposed watermarking algorithm has high security by the visual cryptography and the randomness of discrete fractional random transform. The experimental results show that the proposed watermarking algorithm is imperceptible and moreover is robust against JPEG compression, common image processing distortions.

Digital Image Watermarking Using Bidimensional Empirical Mode Decomposition in Wavelet Domain

In this paper a blind watermarking algorithm for digital image is presented. The proposed method operates in wavelet domain. The watermark is decomposed into 2D-IMFs(intrinsic mode functions)using BEMD (bidimensional empirical mode decomposition) which is the 2-dimensional extension of1 dimensional empirical mode decomposition. The CDMA (code division multiple access) SS (spread spectrum) technique is applied to watermark imbedding and detection process. In watermark embedding process the each IMF of watermark is embed middle frequency subimages in wavelet domain, so subimages just include partial information about embedded watermark. By characteristics of BEMD, when the partial information of watermark is synthesized, the original watermark is reconstructed. The experimental results show that the proposed watermarking algorithm is in almost invisible difference between original image and watermarked image and moreover is robust against JPEG compression, common image processing distortions.

A video zero-watermarking algorithm based on LPM

To resist geometrical attacks, the video zero watermarking algorithm based on log-polar transform presented in this paper. In our method, an original image transformed in log-polar coordinate after transformation of 2D DWT and 3D DCT. In experiment, the proposed method was evaluated the performance of resistance against attacks such as noise attack, rotation attack, compression attack and frame attack. The experiment results show that this algorithm can effectively resist against geometric attacks, and it has high robustness to the noise, filtering, compression and other common attacks. The bit error rate of the proposed algorithm is less than 0.06 for all tested attacks.

Image Watermarking for Identification Forgery Prevention

In this paper, a new image watermarking algorithm is proposed which can hide specific information of an ID card`s owner in photo image for preventing ID`s photo forgery. Proposed algorithm uses the image segmentation and the correlation peak position modulation of spread spectrum. The watermark embedded in photo ensures not only robustness against printing and scanning but also sufficient information capacity hiding unique number such as social security numbers in small-sized photo. Another advantage of proposed method is extracting accurate information with error tolerance within some rotation range by using unit sample space not instead pixels for insertion and extraction of information. 40 bits information can be embedded and extracted at sized ID photo with BER value of 0 % when the test condition is 300dpi scanner and photo printer with 22 photos. In conclusion, proposed algorithm shows the robustness for noise and rotational errors occured during printing and scanning.

Secure Audio Forensic Marking Algorithm Using 2D Barcode in DWT-DFRNT Domain

We created a robust and secure forensic marking algorithm through the process of hiding information in a two-dimensional (2D) barcode and embedding it into the discrete wavelet transformation-discrete fractional random transformation (DWT-DFRNT) domain using the quantization technique. We hid information in the 2D barcode, encoded it with the block code that we developed, and then converted it through scrambling. The security of the algorithm was greatly improved by increasing the calculation complexity through hiding the embedded information. Forensic marks were embedded into the DWT-DFRNT dual domain. The 2D-DWT used for this was applied to the frequency division and the DFRNT was applied to increase the algorithm security by randomly mixing the pieces of information so that they could be embedded in unpredictable locations in a certain frequency space. The bit error generated in the extraction process was corrected by the self-error-correction function of the block code and 2D barcode. The experimental result showed that the information contained in the 2D barcode was accurately extracted from the forensic marks within the error correction range.

A Digital Watermarking Scheme Using Hologram Quantization

In this paper, we propose a digital watermarking scheme that uses hologram quantization to spread the watermark information and analyze the cover image detail. The watermark is a hologram generated using a QR code and quantization based on the cover image. This hologram is transformed by a discrete fractional random transform with a random seed β to make the watermark. The generated watermark can then be embedded into the subband of the discrete wavelet transform (DWT). The proposed scheme includes encryption techniques for security, and is robust because the watermark is inserted in the DWT. When conventional methods are used to watermark an image, the invisibility is poor in the boundary region, but using the proposed method reduces the bit error rate to just 0–0.45%.

A Forensic Marking Algorithm Based on DWT-SVD Using Hologram

In this paper, a new forensic watermarking algorithm which generates digital hologram from forensic mark and embeds it into DWT-SVD domain was suggested. Forensic watermarking is used to trace the illegal distribution. For the purpose of the high capacity, off-axis hologram is generated from forensic m and the hologram is embedded into subband of the DWT domain, so that we could reduce the signal interference. Also, we improved the algorithm safety and detection performance by using SVD for the signal embedded hologram. As a result, we were able to embed 128bits forensic mark for each step and totally 384bits can be embedded and trace the 3 distribution steps.