数字视频伪造被动取证技术研究综述

数字视频伪造被动取证技术直接依据已获得的视频数据本身来判别其真实性,具有更好的适应性,逐渐成为取证研究领域的主流.为了从整体上梳理与描述数字视频伪造被动取证技术,分析了常见的视频伪造操作的特点和它们遗留的痕迹以及对视频被动取证的影响,从取证手段和采用技术2个角度,归纳与总结了基于数字视频来源、基于视频篡改遗留痕迹、基于...     

数字视频篡改痕迹的被动检测技术综述

随着DEEPFAKE等人工智能方法对数字媒体数据的篡改方式越来越强大,再次掀起了全球各国政府、人民对数字媒体篡改问题的关注和焦虑.无论是传统的篡改攻击,还是智能的篡改生成,从结果上来看,都加深了人们对数字媒体真实性的质疑.数字视频是当下互联网信息传播的主流方式之一,因此对数字视频篡改痕迹的被动检测具有重大研究意义.本文...     

JPEG图像被动取证研究进展综述

数字图像被动取证是利用图像的固有属性对其真实性认证、拼接区域定位及篡改历史分析的技术。由于大多数图像都需要进行JPEG压缩以便存储和传输,基于JPEG格式的数字图像被动取证越来越受到关注。为了更加全面地对现有取证方法进行梳理与归纳,本文着重对JPEG图像相关的取证技术进行介绍,详细论述了双重JPEG压缩检测、量化矩阵估计和拼接检测与定位方法中的关键技术,分析现有方法存在的问题与面临的困难,并对未来发展方向进行展望。      

移动数字取证技术

对应移动数字取证技术的4个方面:移动设备取证、移动系统取证、移动网络取证和移动应用取证,给出了移动设备取证的步骤和手段,基于i OS和Android系统的数字取证技术及其特点,移动网络下数字取证的基本手段和技术,移动应用取证的基本特征;认为随着越来越多的新概念和新技术的发展,未来智能移动终端数字取证技术将成为数字取证的主流之一。     

云计算环境下的取证研究

云计算是一种基于互联网的超级计算模式,其在提供强大的计算资源的同时,也给信息安全带来了巨大的风险.本文分析了云计算的特点,提出了云计算环境下取证活动的基本要求,并在此基础上设计了针对云计算环境基本特点的实时取证模型.     

数字可视媒体取证

摘 要：对数字可视媒体取证技术的来源及概念进行了介绍,从原理上详细介绍了具有代表性的二次压缩取证及篡改取证算法。在此基础上,对现有取证算法的相关性以及取证技术中存在的问题进行了一定深度上的讨论,并提出了可视媒体取证发展的新思路。     

数字视频带来技术上的变革和挑战

数字技术正在以迅猛之势在视频行业的各个方面取代模拟技术,带来了全新的产品和业务。这种变化完全改变了视频内容的创建、存储、管理、传送和分配方式以及人们的观赏方式。这种变化在各个地区的表现不尽相同,这与当地的基础设施是否完善、服务商是否积极推动、市场的竞争态势以及用户对新兴视频业务的态度等各种因素有关。但是从根本上而言,数字技术已经使视频内容、传输机制和观看体验等发生了巨大的变化,这种变化几乎表现在视频业的所有方面。     

数字视频指纹技术分析

数字视频指纹是实现网络视频盗版监测以及非法视频监测的一种有效的技术手段,对数字视频指纹技术的基本特征和数字视频指纹技术难点进行了阐述,提出了数字视频指纹研究的方法,并分析了数字视频指纹技术的发展前景。     

视频化计算机取证系统的设计与实现

文章基于计算机屏幕录影技术,提出一种新的计算机取证证据关联形式,即视频化计算机取证系统（VCFS）模型。基于该模型,设计并实现了用户行为违反监控规则情况下计算机终端的视频取证功能。最后通过分析在各种环境下视频化计算机取证系统的效率,得出影响系统效率的关键因素,并提出相应的解决思路。     

A passive multi-purpose scheme based on periodicity analysis of CFA artifacts for image forensics

We propose a passive multi-purpose scheme for photographic image (PIM) detection and a device class identification method. The motivation for the scheme is the periodicity phenomenon caused by color filter arrays (CFAs) and the demosaicing process. The phenomenon only occurs in the Fourier spectrum in PIMs. The proposed scheme exploits prediction error statistics, local peak detection, and a PIM classifier to analyze the phenomenon for PIM detection. We also develop a hierarchical classifier for device class identification based on the analysis of local peaks in the Fourier spectrum.To evaluate the scheme’s performance, we compile a test dataset of PIMs and PRCG (photorealistic computer graphics) images, and analyze the impact of leak peak detection, JPEG lossy compression, and cropping operations on PIM detection. The accuracy rate of the scheme on 5805 test images is 95.56%, which is higher than that of the methods proposed in Sutthiwan et al. (2009) [1] and Gallagher and Chen (2008) [2]. In addition, for device class identification, the precision rate of the proposed method is at least 93% on Canon, Sony, and Nikon images. The experiment results demonstrate the efficacy of the proposed multi-purpose scheme.     

稳健性图像复制-黏贴篡改被动认证

图像复制-黏贴(copy-move)是一类的常见的图像篡改手段,篡改通过将图像中一部分区域复制并黏贴到同一幅图像另一区域后起到掩盖被覆盖内容的目的。由于篡改者为了使篡改更加逼真或者试图增加检测难度,往往在黏贴图像块之前对图像块进行加噪、模糊或者旋转缩放等后续处理。目前检测这类篡改的认证方法主要归纳为三类：变换域鲁棒特征子块匹配方法、旋转不变特征子块匹配方法和特征点匹配方法。本文对采用这三类方法的国内外文献进行了系统的分析和归纳并对未来研究方向进行了展望。     

JPEG forensics scheme for signature embedding and packet‐level detection

As the volume of multimedia digital information transmitted over the Internet continues to rise, the problem of preventing the unauthorized tampering and dissemination of digital content has emerged as a major concern. Thus, the present study proposes a forensic scheme for tracking the dissemination of copyright‐protected JPEG images over the Internet. The proposed scheme incorporates two basic mechanisms, namely signature embedding and signature detecting. To preserve the quality of the protected JPEG images, the signature is embedded at the application layer. By contrast, the signature detection process is performed at the packet level in order to improve the scalability of the proposed mechanism. For any flows regarded as suspicious, the signatures embedded in the JPEG packet trains are compared with the known digital signatures for forensic purposes. The experimental results show that the embedded signature has no effect on the visual quality of the JPEG image. Moreover, it is shown that the computational complexity of the proposed detection scheme is significantly lower than that of existing application‐level schemes. Thus, the scheme provides an ideal solution for the forensic analysis of JPEG streams over large‐scale network environments such as the Internet. Copyright © 2013 John Wiley & Sons, Ltd.     

基于数字水印的视频多点广播立即源认证模型

提出一种视频多点广播立即源认证模型。TESLA多点广播源认证的基础上，采用基于查找表的视频水印算法，将视频重要分量的消息认证码、公开密钥和立即认证散列信息作为数字水印嵌入到视频的非重要分量中，达到视频数据的立即源认识；同时节约一定的传输带宽，并给出公开延迟时闾间隔的一种计算方法。     

开源视频服务器软件MJPG-streamer的研究和应用

针对嵌入式设备在进行多媒体数据处理时存在的资源限制问题,采用了一种开源视频服务器软件MJPG—streamer完成多媒体数据的处理及存储,基于该软件的特点和体系结构,通过修改MJPG—streamer的源代码,添加新的功能模块,以增强这款软件的功能。并重新交叉编译后,移植到嵌入式系统中,以实现一个可控制前端设备的基于Arm9的嵌入式远程视频监控系统。实验结果表明,该方法很好地增强了视频数据处理的效果,并可流畅地在客户端播放浏览器。     

中国电视台视频记录存储设备的发展历史和前瞻

追述中国电视台60年来视频记录存储设备发展的历史,从只是依靠电影胶片记录存储电视信号,发展到当今的标清和高清录像机、蓝光盘、高清记录存储卡、数据流磁带机、以多通道和网络化的硬盘阵列为主的视频服务器系统等等,存储媒介也从胶片和磁带,向多媒体记录方式的文件化、高清化、网络化转变.从现代科技的视角阐述了对电视台未来视频记录存储设备发展策略的思考.     

Content fragile watermarking for H.264/AVC video authentication

Discrete cosine transform is exploited in this work to generate the authentication data that are treated as a fragile watermark. This watermark is embedded in the motion vectors. The advances in multimedia technologies and digital processing tools have brought with them new challenges for the source and content authentication. To ensure the integrity of the H.264/AVC video stream, we introduce an approach based on a content fragile video watermarking method using an independent authentication of each group of pictures (GOPs) within the video. This technique uses robust visual features extracted from the video pertaining to the set of selected macroblocs (MBs) which hold the best partition mode in a tree-structured motion compensation process. An additional security degree is offered by the proposed method through using a more secured keyed function HMAC-SHA-256 and randomly choosing candidates from already selected MBs. In here, the watermark detection and verification processes are blind, whereas the tampered frames detection is not since it needs the original frames within the tampered GOPs. The proposed scheme achieves an accurate authentication technique with a high fragility and fidelity whilst maintaining the original bitrate and the perceptual quality. Furthermore, its ability to detect the tampered frames in case of spatial, temporal and colour manipulations is confirmed.     

A source authentication scheme based on message recovery digital signature for multicast

The source authentication is an important issue for the multicast applications because it can let the receiver know whether the multicast message is sent from a legal source or not. However, the previously related schemes did not provide the confidentiality for data packets. In addition, the communication costs of these schemes are still high for real‐time applications in the multicast environments. To solve the aforementioned problems, we propose a new source authentication scheme based on message recovery signature for multicast in this paper. In the proposed scheme, the encrypted data can be embedded in the digital signature, so the communication loads can be greatly reduced. In addition, the digital signature contains the encrypted data, and thus the confidentiality of data packets can be well protected. According to the aforementioned advantages, the proposed scheme is securer and more efficient than the related works for the real‐time applications. Copyright © 2013 John Wiley & Sons, Ltd.