Guest Editorial Special Issue on Information Security

⎯Recently, an edge adaptive image steganographic method based on least significant bit (LSB) matching revisited (EA-LSBMR) has been proposed, which holds good visual quality and proper security under appropriate embedding rates. However, from the extensive experiments to EA-LSBMR, we find that the discrete Fourier transform (DFT) spectrum of pixelpairs differences histogram still reveals the presence of a secret message even in a low embedding rate. To enhance the security, a modified scheme is proposed in this paper, which can defeat the above-mentioned analysis and keep the visual quality better than EA-LSBMR in higher embedding rates. Experimental results using a latest universal steganalysis method have demonstrated the proposed method’s good performance. Index Terms⎯Block-based steganography, least significant bit matching revisited, pixel-pairs differences histogram, steganalysis. doi: 10.3969/j.issn.1674-862X.2011.04.002 Full text link: http://www.intl-jest.com:88/index.php?p=archive&action=download&archive_id=730 Double-Layer Data Embedding Scheme Based on Three-Pixel Differences Yi-Hui Chen, Chiao-Chih Huang, and Chi-Shiang Chan Abstract⎯Steganography is a technique to hide the secret data into digital media without getting any unexpected notices. The traditional steganographic method, namely least significant bit (LSB) replacement, is a simple but insecure scheme. To overcome the traditional drawbacks, this paper proposes a steganographic scheme, which is called double-layer hiding method. The experimental results confirm that the proposed scheme achieves better hiding capacity with high ability of resisting security analysis. Index Terms⎯Hiding capacity, least significant bit replacement, security analysis, steganography, visual quality. doi: 10.3969/j.issn.1674-862X.2011.04.003 Full text link: http://www.intl-jest.com:88/index.php?p=archive&action=download&archive_id=731⎯Steganography is a technique to hide the secret data into digital media without getting any unexpected notices. The traditional steganographic method, namely least significant bit (LSB) replacement, is a simple but insecure scheme. To overcome the traditional drawbacks, this paper proposes a steganographic scheme, which is called double-layer hiding method. The experimental results confirm that the proposed scheme achieves better hiding capacity with high ability of resisting security analysis. Index Terms⎯Hiding capacity, least significant bit replacement, security analysis, steganography, visual quality. doi: 10.3969/j.issn.1674-862X.2011.04.003 Full text link: http://www.intl-jest.com:88/index.php?p=archive&action=download&archive_id=731 A Novel Scheme for Compression of Cash Images Li Li, Feng Wang, Jian-Feng Lu, and Da-Xing Zhang Abstract⎯In the field of economy, there are more and more electronic scanning cash images, which need to be compressed in a higher compression ratio. This paper proposes a specific compression algorithm for cash images. First, according to cash image characteristics and standard JPEG (joint photographic experts group) compression, image re-ordering techniques are analyzed, and the method of modifying some blocks into single color blocks is adopted. Then, a suitable quantization table for cash images is obtained. Experimental results show that the method is effective. Index Terms⎯Compression ratio, correlation, joint photographic experts group, preprocess, quantization table, re-ordering. doi: 10.3969/j.issn.1674-862X.2011.04.004 Full text link: http://www.intl-jest.com:88/index.php?p=archive&action=download&archive_id=732⎯In the field of economy, there are more and more electronic scanning cash images, which need to be compressed in a higher compression ratio. This paper proposes a specific compression algorithm for cash images. First, according to cash image characteristics and standard JPEG (joint photographic experts group) compression, image re-ordering techniques are analyzed, and the method of modifying some blocks into single color blocks is adopted. Then, a suitable quantization table for cash images is obtained. Experimental results show that the method is effective. Index Terms⎯Compression ratio, correlation, joint photographic experts group, preprocess, quantization table, re-ordering. doi: 10.3969/j.issn.1674-862X.2011.04.004 Full text link: http://www.intl-jest.com:88/index.php?p=archive&action=download&archive_id=732 JOURNAL OF ELECTRONIC SCIENCE AND TECHNOLOGY, VOL. 9, NO. 3, SEPTEMBER 2011 4 Robust Watermarking with Kernels-Alternated Error Diffusion and Weighted Lookup Table in Halftone Images Jing-Ming Guo Abstract⎯A halftone watermarking method of high quality, robustness, and capacity flexibility is presented in this paper. An objective halftone image quality evaluation method based on the human visual system obtained by a least-mean-square algorithm is also introduced. In the encoder, the kernels-alternated error diffusion (KAEDF) is applied. It is able to maintain the computational complexity at the same level as ordinary error diffusion. Compared with Hel-Or using ordered dithering, the proposed KAEDF yields a better image quality through using error diffusion. We also propose a weighted lookup table (WLUT) in the decoder instead of lookup table (LUT), as proposed by Pei and Guo, so as to achieve a higher decoded rate. As the experimental results demonstrate, this technique is able to guard against degradation due to tampering, cropping, rotation, and print-and-scan processes in error-diffused halftone images. Index Terms⎯Error diffusion, halftoning, lookup table, watermarking. doi: 10.3969/j.issn.1674-862X.2011.04.005 Full text link: http://www.intl-jest.com:88/index.php?p=archive&action=download&archive_id=733 Steganalysis Using Fractal Block Codes and AP Clustering in Grayscale Images Guang-Yu Kang, Yu-Xin Su, Shi-Ze Guo, Rui-Xu Guo, and Zhe-Ming Lu Abstract⎯This paper presents a universal scheme (also called blind scheme) based on fractal compression and affinity propagation (AP) clustering to distinguish stego-images from cover grayscale images, which is a very challenging problem in steganalysis. Since fractal codes represent the “self-similarity” features of natural images, we adopt the statistical moment of fractal codes as the image features. We first build an image set to store the statistical features of natural images with and without hidden messages, and then apply the AP clustering technique to group this set. The experimental result shows that the proposed scheme performs better than Fridrich’s traditional method. Index Terms⎯Affinity propagation clustering, fractal compression, steganalysis, universal steganalysis. doi: 10.3969/j.issn.1674-862X.2011.04.006 Full text link: http://www.intl-jest.com:88/index.php?p=archive&action=download&archive_id=734 Construction of General (k, n) Probabilistic Visual Cryptography Scheme Ching-Nung Yang, Chih-Cheng Wu, and Feng Liu Abstract⎯Visual cryptography scheme (VCS) is a secure method that encrypts a secret image by subdividing it into shadow images. Due to the nature of encryption VCS is categorized into two types: the deterministic VCS (DVCS) and the probabilistic VCS (PVCS). For the DVCS, we use m (known as the pixel expansion) subpixels to represent a secret pixel. The PVCS uses only one subpixel to represent a secret pixel, while the quality of reconstructed image is degraded. A well-known construction of (k, n)-PVCS is obtained from the (k, n)-DVCS. In this paper, we show another construction of (k, n)-PVCS by extending the (k, k)-PVCS. Index Terms⎯Probabilistic visual cryptography, visual cryptography, visual secret sharing. doi: 10.3969/j.issn.1674-862X.2011.04.007 Full text link: http://www.intl-jest.com:88/index.php?p=archive&action=download&archive_id=735 JOURNAL OF ELECTRONIC SCIENCE AND TECHNOLOGY, VOL. 9, NO. 1, MARCH 2011 5 A Visual Secret Sharing Scheme for Progressively Restoring Secrets Chin-Chen Chang, Yi-Pei Hsieh, and Chi-Cheng Liao Abstract⎯Visual secret sharing has received more and more attention over the past years due to the fact that neither complex computation nor cryptographic knowledge is required to decrypt the secret image directly according to the characteristics of the human vision system. Considering the issue of sharing the secret image at multiple image resolutions with the meaningful shadows, in this paper, we present a friendly progressive visual secret sharing scheme without expanding the image size in the shadows and the reconstructed secret image based on applying a 2×2-sized block-wise operation to generate the shadows block by block. The proposed method can achieve these benefits: 1) the generated shadows are meaningful, and their sizes are not expanded, and 2) the secret image can be recovered at different resolutions by stacking different quantities of shadows together. The experimental results also show that the proposed method is superior to other compared schemes. Index Terms⎯Friendly management, multiple image resolutions, progressive restoring secrets, visual secret sharing. doi: 10.3969/j.issn.1674-862X.2011.04.008 Full text link: http://www.intl-jest.com:88/index.php?p=archive&action=download&archive_id=736⎯Visual secret sharing has received more and more attention over the past years due to the fact that neither complex computation nor cryptographic knowledge is required to decrypt the secret image directly according to the characteristics of the human vision system. Considering the issue of sharing the secret image at multiple image resolutions with the meaningful shadows, in this paper, we present a friendly progressive visual secret sharing scheme without expanding the image size in the shadows and the reconstructed secret image based on applying a 2×2-sized block-wise operation to generate the shadows block by block. The proposed method can achieve these benefits: 1) the generated shadows are meaningful, and their sizes are not expanded, and 2) the secret image can be recovered at different resolutions by stacking different quantities of shadows together. The experimental results also show that the proposed method is superior to other compared schemes. Index Terms⎯Friendly management, multiple image resolutions, progressive restoring secrets, visual secret sharing. doi: 10.3969/j.issn.1674-862X.2011.04.008 Full text link: http://www.intl-jest.com:88/index.php?p=archive&action=download&archive_id=736 Media Sharing Scheme with Cheater Identification and Content Reconstruction