Multimedia Forensic Techniques

Crime is becoming a main problem day by day of our society so it is necessary to take some steps to overcome the problem that’s why we introduce the term multimedia forensic. Multimedia forensic can be defined as a science by which analyzing of a digital asset for an assessment for some special purpose and to extract some important information and in some kind of investigation for some kind of digital documentary. Multimedia forensic provides the path to test the digital data from a source  that may be an authorized image, order or any other document to identify in the forensic. In the multimedia forensic images, video, audio, etc .contents covers. In multimedia forensic techniques, the main focus is that to identify the source of the digital device it may be a mobile phone, digital camera, etc. with the help of media, similarly, the forensic media detects the evidence by which it is obtained. For preventing the false detection lens are used with the characteristics of dust spots. All the result depends on the lens detection, even under heavy compression and down sampling. Investigation of a crime is a multifaceted and complicated procedure which commences at the crime scene, resumes in a forensic laboratory to conduct in-depth examination, and concludes in the court room wherein the conclusive verdict is passed. Investigators require assistance in each and every one of these stages for making their employment as efficient and competent as achievable. Now the question arise that why the multimedia forensic  is required then we have some answers.

 

Digital tampering: In this powerful techniques and methods are used to find out the solution in natural image. Firstly they find the reasons which make the result false and make a different sense of the result forensic technique is mainly focus in the main reason behind the image it try to remove the false image completely and gives the better result in a better and easy way  due to this it may be possible that other properties  which are not directly connected to that but according to forensic they are relate to each other they can disturb those images. All of these are used to investigate the true result and give the best result in a better way in a short period of time with full authenticity. This is called passive technology because there is no prior information about the content in this whole mechanism .

 

Digital source identification: It is the part of the digital image forensic  whose main purpose is establishing the relationship linking the digital device and the image, by exploitation in different steps with different procedures. In this a different type of voice is generated which is not audible with the human eye it is a unique pattern of voice which represent the unique fingerprint of a specific device. That voice is not visible by the human eye but it can be analyzed by some identifications.

 

Digital counter forensic:  It’s a new method of research in digital forensic science which aim is to identify the weakness by which they are trying to make the fool to the science or we can say to find the techniques by which they are trying to make the science fool. In this technique forensic try to take some tools  and countermeasures to find out the attacks. This category of attacks are generally intented for a solitary or division of forensic tools & attempt to obscure the evidence of a specific tempering.

 

Digital watermarking: In this type of technique according to the procedure some information attached with the image or with the content  ,video ,audio and this attachment is also known as watermarking it is used to degrade the quality of the content and to degrade the performance of the content. This attached information is identified at any level for dissimilar purpose involving possession evidence, copyright defense, admission control and tamper detection. This technology is far active rather than other because it uses the known information attach with the content at the time of recording.

 

Multimedia forensic: With the help of broadband all the people enjoying  to communicate with each and share things with each other at any time with any person in all over the world in a network. But with all of these benefits there are some drawbacks in this that any body can easily manipulate the voice and video and image and easily repacking the data, illegal alteration, unauthorized redistribution of multimedia. These are become  serious threats for government and commercial groups as well.

 

Cryptographic tools and other access tools are used to support the secure delivery of multimedia over the network which is used to protect and to transmit the best content at the receiver end and the receiver can easily decrypt the data according to its requirement.  For post delivery protection we use the various tools like digital tampering, digital source identification, digital watermarking, digital counter forensic, digital fingerprinting . All of these are mainly used for the better distribution of the data at the receiver end with the use of these multimedia technology.  Guaranting the suitable use of multimedia content, nevertheless, is not any longer a safety concern with a solitary opposition. A group of attackers with dissimilar fingerprinted versions of the identical content are capable of collectively mounting attacks and efficiently removing the traces of the fingerprints. Multimedia fingerprints should not only be vigorous in opposition to attacks by a solitary attacker, they should in addition oppose such multi-user collusion. This neccesiates the digital rights enforcer to have a insightful perceptive of multi-user collusion and design anti-collusion fingerprints for multimedia.