With the innovations and development in sophisticated video editing technology, it is becoming increasingly significant to assure the trustworthiness of video information. Today digital videos are also increasingly transmitted over non-secure channels, such as the Internet. Therefore, in surveillance, medical, and various other fields, video content must be protected against attempts to manipulate them. Video authentication has gained much attention in recent years. However, many existing authentication techniques have their own advantages and obvious drawbacks; we propose a novel authentication technique that uses an intelligent approach for video authentication. This book chapter presents an intelligent video authentication algorithm using support vector machine, which is a non-linear classifier, and its applications. It covers both kinds of tampering attacks, spatial and temporal. It uses a database of more than 4000 tampered and non-tampered video frames and gives excellent results with 95% classification accuracy. The authors discuss a vast diversity of tampering attacks, which can be possible for video sequences. Their algorithm gives very good results for almost all kinds of tampering attacks.
Top1. Introduction
Visual information has always had a great role in our society, as well as in history as today. Its control is always being very significant for the individuals, organizations and for countries too. It can express from a very tiny moment of our life to the history of the universe. In contrast to early days of human society, today we can transmit the information thousands of kilometers within a couple of seconds. This makes a great impact on the development of our society. In today’s digital era, communication and compression techniques facilitate sharing of multimedia data such as image and video (Upadhyay, Singh, Vatsa, and Singh, 2007). With the wide-spread availability of sophisticated and low-cost digital video cameras and the pervasiveness of video sharing websites, digital videos are playing a more important role in our daily life. Since digital videos can be manipulated maliciously, their authenticity cannot be taken for granted. Although it is fact that tampering with a digital video is more complex and challenging task than tampering with a single image, but today’s elegant and sophisticated video editing technology makes it easier to tamper with videos. The increasing sophistication of computing devices and its equipment has made digital manipulation of video sequences very easy to perform. Ensuring the trustworthiness and integrity of a digital video has posed considerable challenges. This is because of one of the significant properties of digital data, i.e., a copy of digital multimedia data behaves the same as the original one.
1.1. Necessity of Video Authentication
In some of the video applications, the authenticity of video data is of much interest such as in video surveillance, forensic investigations of digital videos, law enforcement, and content ownership (Upadhyay, Singh, Vatsa, and Singh, 2007). For example, in court of law, it is significant to establish the trustworthiness of any video that is used as evidence. As in another scenario, for example, suppose a motionless video recorder for surveillance purpose, is positioned on the pillar of a railway platform to capture every activity on that platform along a side. It would be quite simple to remove a certain activity, people or even an event by simply removing a handful of frames from this type of video sequences. On the other hand it would also be feasible to insert, into this video, certain objects, people taken from different cameras and in different time. These are the instances where modifications are not tolerated. Thus video authentication is a process which ascertains that the content in a given video is authentic and exactly same as when captured. For verifying the credibility of received video content, and to detect malicious tampering attacks and preventing various types of forgeries, performed on video data, video authentication techniques are used.
In past few years, watermarking and digital signatures have been widely used for the purpose of video authentication. Different techniques have their own advantages and shortcomings. In fact, fragile watermarking and digital signatures are the two commonly used schemes for authentication (Peng & Hong, 2001). Fragile watermarking embeds the authentication data into the primary multimedia sources, while digital signature stores the authentication data separately, either in user defined field, as like, in the header of MPEG sequence, or in a separate file (Peng & Hong, 2001). Moreover there has also been worked on intelligent techniques for video authentication (Upadhyay, Singh, Vatsa, and Singh, 2007; Singh, Vatsa, Singh, and Upadhyay, 2008). Intelligent authentication techniques use learning based techniques for authentication purpose. Apart from these digital signature, fragile watermarking, and intelligent techniques, some other authentication techniques are also introduced by researchers, which are specifically designed for various cases of malicious attacks.
2. Video Tampering
A continuous video data 
is a scalar real valued function of two spatial dimensions 
and 
and time
, usually observed in a rectangular spatial window W over some time interval T. If 
is modification vector then the tampered video
would also be a scalar real valued function of spatial dimensions 
and 
and time 
as follows: