This paper presents a new fast video watermarking scheme in spatial domain for embedded device identity verification.
A binary watermark signal, which is produced by the identity of the embedded device such as the disc video player, is
permutated using sequence numbers generated by a secret key. And then it is encoded by Gray code. Each bit of the
binary encoded watermark is embedded four times in different positions, by modifying the intensities of a nonoverlapping
block of 8*8 of the blue component of the frames in host video. In watermarking extract scheme, the frame
of the watermarked video and the original video are decoded to images. And the intensities of a block of 8*8 of all
components of the frame images in the watermarked and the original video are compared to calculate the probability of
detecting '0' or '1' for extracting binary watermark. Both the embedding and the extraction of watermarks are done in the
spatial domain, so the computational cost is low. Then the digital watermark with the identity information is embedded
in real time to the video image when the embedded devices play their videos. Experimental results show that the
algorithm has obvious low complexity, and the strong robustness against distortion, deleting, and cropping operations.
This paper presents a new robust watermarking extract scheme for color image by using scale invariant features transform image correction. A binary watermark image is permuted with sequence numbers generated by a secret key in a spatiotemporal chaos system. Then, the binary image watermark was encoded by Gray code, and then adaptively embedded into low frequency components of discrete cosine transform domain in the original color image's blue channel. In watermarking extract scheme, the scale invariant features of images are extracted, and the match points between the watermarking image and the reference image are found. Then the watermarking image is corrected by affine transform of these match points. Although the watermark is only embedded into the blue channel, the other channel can provide the position information of the image processing operations. By comparing the intensities of the low frequency components of discrete cosine transform domain of the corrected and the original image, the extraction method of the watermark is calculating the probability of detecting '0' or '1'. At last, the watermark is extracted from the corrected image. Experimental results show that the proposed scheme is robust and secure against a wide range of image processing operations such as global affine transformation, filtering and lossy compression.
The network-attached optical disk storage system has the advantages of the network-attached storage system and the optical storage device. Due to the data reliability and the removability of the storage medium, this optical storage system is very effective on massive data providing and backup. Recently, achievements have been made in security models and policies in a distributed network system environment and the network-attached storage system environment. However, the relevant research is not enough in the network-attached optical disk storage system, especially in a network-attached optical disc device. So it is significant to analyze the security policy and setup a good security model for the network-attached optical disk storage system. This paper makes a theoretical analysis on the security policy in the network-attached optical disk storage system. Firstly, the difference of the network-attached optical disk storage system and the distributed network system environment is presented. The network-attached optical disk storage system is a special distributed network system, and to meet the requirements of the system security, we use the authentication and key exchange protocol method to decide who is authorized to have what access rights on which objects with respect to some security models and policies in compute system. Secondly, we compare the effect of several types of authentication and key distribution protocols in a distributed network system environment. Then we port these authentication and key exchange protocols on the network-attached optical disk storage system environment. Based on these analyses, this paper proposes a secure key management scheme for security services in the network-attached optical disk storage system over open networks. This scheme focuses on the framework for authentication and the centralized key management, and future work will focus on dynamic membership management.