Zhongxuan Liu

Selective video encryption based on advanced video coding

Advanced Video Coding is recently announced and widely used, although the according protection means have not been developed thoroughly. In this paper, a selective encryption scheme is constructed on Advanced Video Coding. During AVC encoding, such sensitive data as intra-prediction mode, residue data, inter-prediction mode and motion vector are partially encrypted. This encryption scheme keeps secure against brute-force attack, replacement attack or known-plaintext attack, combines encryption process with compression process with low cost, and keeps the file format unchanged with some direct operations (such as displaying, time seeking, copying, cutting, etc.) supported. These properties make it suitable for secure video transmission.

Secure Distribution Scheme for Compressed Data Streams

A secure distribution scheme is proposed for compressed videos, which is based on a compression domain watermarking algorithm. At the server end, the watermarking-based encryption algorithm is used to encrypt the compressed data stream. At the receiver end, the joint fingerprint embedding and decryption (JFD) algorithm is adopted to decrypt and fingerprint video data simultaneously. For the features of the watermarking algorithm, this scheme is easy to extract the fingerprint and detect the colluders, and is suitable for distributing compressed videos. Theoretical analysis and experimental results prove its practice.

Secure media content distribution based on the improved set-top box in IPTV

In this paper, some means are proposed to improve the performances of the set-top box (STB) based media distribution schemes for IPTV. Firstly, the lightweight packet encryption is used to replace traditional complete encryption in order to reduce the time cost. Secondly, a method is introduced to form a unique customer code and generates a unique media copy for each customer in order to trace illegal redistributors. Thirdly, the desynchronization operations are introduced to make different copies in order to resist collusion attacks. Analyses and experiments show that the proposed packet encryption saves much time cost compared with traditional encryption and the saved time cost is enough for the added new operations. Additionally, the produced media copy is different from each other, and their collusion will generate a copy with much degradation, which can resist the content leakage from the gap between STB and TV set.

Joint Fingerprint Embedding and Decryption for Video Distribution

A secure video distribution scheme is proposed, which embeds a fingerprint code into the video content during decryption process. At the server side, the video content is scrambled by motion vector (MV) encryption. At the customer side, the video content is decrypted and fingerprinted simultaneously under the control of both the key and the fingerprint. For MV decryption and fingerprint embedding are both based on MV modification, they are combined into homogenous operations. Thus, it is difficult for attackers to get the clear video content from the gap between the decryption operation and the embedding operation. To counter collusion attacks, the fingerprint can be encoded with collusion-resistant codes before being embedded. Furthermore, by improving the watermarking strength, the colluded copys quality will be reduced greatly, which makes collusion attacks out of work.

Secure multimedia watermarking authentication in wavelet domain

With the wide application of multimedia data, multimedia content protection becomes urgent. Until now, various means have been reported that can be classified into several types according to their functionalities, such as data encryption, digital watermarking, or data authentication. They are used to protect multimedia datas confidentiality, ownership, and integrity, respectively. A wavelet-based multifeature semifragile multimedia authentication scheme is proposed. According to the approximation component and the energy relationship between the subbands of the detail component, global feature and local feature are both generated. Then, the global watermark and local watermark are generated from global feature and local feature, respectively. Two watermarks are then embedded into the multimedia data themselves, in the wavelet domain. Both the feature extraction and embedding processes are controlled by secret keys to improve the security of the proposed scheme. On the receiver side, the extracted watermark and the one generated from the received image are compared to determine the tampered location. A new authentication method is designed, and it is proved valid in the experiments. This authentication scheme is robust to general compression; sensitive to cutting, pasting, or modification; efficient in real-time operation; and secure for practical applications.

Image desynchronization for secure collusion-resilient fingerprint in compression domain

Collusion is a major menace to image fingerprint. Recently, an idea is introduced for collusion-resilient fingerprint by desynchronizing images in raw data. In this paper, we consider compression domain image desynchronization method and its system security. First, appropriate desynchronization forms for compression domain are presented; secondly, the system security is discussed and a secure scheme is proposed; thirdly, for evaluating the visual degradation of space desynchronization, we propose a metric called Synchronized Degradation Metric (SDM). Performance analysis including the experiments indicate the effectiveness of the proposed scheme and the metric.

Quaternion Diffusion for Color Image Filtering

How to combine color and multiscale information is a fundamental question for computer vision, and quite a few color diffusion techniques have been presented. Most of these proposed techniques do not consider the direct interactions between color channel pairs. In this paper, a new method of color diffusion considering these effects is presented, which is based on quaternion diffusion (QD) equation. In addition to showing the solution to linear QD and its analysis, one form of nonlinear QD is discussed. Compared with other color diffusion techniques, considering the interactions between channel pairs, QD has the following advantages: 1) staircasing effect is avoided; 2) as diffusion tensor, the image derivative is regularized without requiring additional convolution; 3) less time is needed. Experimental results demonstrate the effectiveness of linear and nonlinear QD applied to natural color images for denoising by both visual and quantitative evaluations.

Supervised TV logo detection based on SVMS

In this paper a simple and practical technique for supervised TV logo detection based on support vector machines (SVMs) is shown. Specific TV logos are assumed to locate in static regions, usually four corners of one frame. Instead of sampling time averaged frames at frame level, we make use of information of shot boundary detection (SBD) to get three key-frames per shot. After extracting corners in every key-frame, we train several SVM classifiers for specific TV logos using color, edge, and key point features, and then detect logos in these regions of interest corners. At last, a two-step fusion strategy is performed to get optimum and robust performance at shot level. We tested more than 24 hours videos to detect logos of Eurosport TV station and achieved 99.98% of correct detection rate; and also more than 5 hours to detect logos of Cine Confidential, one program of Orange TV station with 99.99% of correct detection rate.

Desynchronized image fingerprint for large scale distribution

Collusion is a major menace to image fingerprint. Recently, an idea is introduced for collusion-resilient fingerprint by space desynchronizing including RST (rotation, scaling and translation) and random bending. In this paper, we proposed a new space desynchronized fingerprint method which is for large scale distribution: image is enlarged and encrypted at sender side; at user side, key sequence is used to only decrypt some parts of image and compose these parts to make a new image copy with fingerprint embedded. This method has two priorities: first, only one image is needed to send to or be downloaded by all users with fingerprint embedded; secondly, the embedded fingerprint is robust to collusion attack. For diminishing the degradation introduced by desynchronization, we consider the image content such as human face. Experiments indicate the effectiveness of our method.

Secure Media Distribution Scheme Based on Chaotic Neural Network

A secure media distribution scheme is proposed in this paper, which distributes different copy of media content to different customer in a secure manner. At the sender side, media content is encrypted with a chaotic neural network based cipher under the control of a secret key. At the receiver side, the encrypted media content is decrypted with the same cipher under the control of both a secret key and the customer information. Thus, the decrypted media copy containing customer information is slightly different from the original one. The difference can be detected and used to trace media contents illegal distribution. The schemes performances, including security, imperceptibility and robustness, are analyzed and tested. It is shown that the scheme is suitable for secure media distribution.