The rapid development of Internet introduces a new set of challenging problem regarding security. To prevent unauthorized copying of digital production from distributing is one of the significant problems. Digital watermarking is a potential method for protecting the ownership rights on digital audio, image and video data. An attack succeeds in defeating a watermarked article if it impairs the watermarking information beyond acceptable limits while maintaining the perceptual quality of the attacked article. Namely, attacks on digital watermarked article must consider both watermarking information survival and the distortion of the attacked stego-media. Current attack benchmarks do not exploit as much knowledge of the watermarked image as possible, also they do not consider the distortion of the attacked stego-media. In this paper, various attacks on digital watermarking have been investigated, and a categorization of different attacks was roughly given; Besides, an Eigen-image-based (ED-based) attack is proposed to deliberately impair the watermarking information without excessively distorting the attacked stego-media, that is not currently included in those benchmark tools.

Most watermark-removal methods treat watermarks as noise and apply denoising approaches to remove them. However, denoising methods remove not only this watermark energy, but also some of the energy of the original image. A trade-off therefore exists: if not enough of the watermark energy is removed, then the watermark will still be detected, but if too much is removed, the image quality will be noticeably poor. To solve this problem, the relationship among the energies of the original image, the watermark and the watermarked image is initially determined using stochastic models. Then, the energy of the watermark is estimated using just-noticeable-distortion (JND). Finally, the watermark energy is removed from the watermarked image based on the energy distribution of its Eigen-images. The experimental results show that the proposed approach yields a mean peak signal-to-noise ratio (PSNR) of the predicted images that is 2.2dB higher than that obtained using the adaptive Wiener filter, and a mean normalized correlation (NC) value of the extracted watermarks that is 0.27 lower than that obtained using the adaptive Wiener filter. In removing watermark energy from 100 randomly selected watermarked images in which watermarks were embedded using the ¡¥Broken Arrows (BA)¡¦ algorithm proposed for the second Breaking Our Watermarking System (BOWS-2) contest, the mean PSNR of 100 predicted images is 24.1dB and the proposed approach successfully removed watermarks from 90 of these images. This result exceeds the minimum requirement of PSNR 20dB for the BOWS-2 contest. Clearly, the proposed approach is a very effective watermark-removal approach for removing watermarks.

Childhood sexual abuse (CSA) has been the subject of much recent controversy as a result of Rind, Tromovitch and Bauserman's (1998) meta-analytic examination of CSA, which found a weak relationship between CSA and self-reported psychopathology in college samples. There have been few studies of CSA which look beyond self-report. The present study is an exploration of the relationships between CSA, quantitative electroencephalographic (QEEG), neuropsychological, and psychological measurements in 24 high-functioning, unmedicated CSA adults who were matched for age, gender, and handedness with a group of adults without CSA (NCSA). The objectives of this study were to: 1) examine EEG abnormalities associated with CSA, 2) investigate QEEG cortical coherence in the groups using neuroelectric Eigen image (NEI) connectivity indices (Hudspeth, 1999), 3) integrate personality differences associated with CSA with EEG differences, and 4) better understand left versus right hemisphere functioning in CSA using intelligence testing. An examination of QEEG cortical coherence revealed moderate to large effect sizes indicating patterns of decreased connectivity between brain regions on the right frontally in the delta band, and frontally and centro-temporally on the right in the alpha band, and posteriorly in the alpha and beta bands, as well as in the cross-correlation; increased connectivity between brain regions was evidenced centrally across the motor strip and on the left temporally in the delta band, which differentiated the groups. Large effect sizes obtained on measures of personality were related to poorer adjustment for CSA adults in comparison to NCSA adults. In contrast to prior findings with clinical groups (Black, Hudspeth, Townsend, & Bodenhamer-Davis, 2002; Ito et al., 1993), hypotheses related to QEEG cortical coherence (left hemisphere alpha hypercoherence and right hemisphere theta hypocoherence), EEG abnormalities, and IQ (Verbal less than Performance) were not supported. Walker's (2003) theoretical modular coherence model was utilized to integrate coherence and personality variables and provide treatment options.