Questioned Documents: Tools Used in Questioned Document Analysis

The most significant tool of a document examiner is his or her vision. In addition to this tool, the outer tools which facilitate the examiner to see, evaluate and record more than is evident to the unaided eye. The microscope is the instrument that makes it possible to see physical evidence on documents which would otherwise remain invisible and useless. The normal unaided human eye can differentiate only 250 separate lines to the inch. This means that the small details which involve proportions or separations of less than 1/250th of an inch are not seen by the eye, and sees them as a connected, solid mass. These tools can be grouped into six categories:

1. Basic measuring tools

2. Magnification (magnifiers/ microscopes)

3. Light Sources

4. Special Instruments

5. Photography

6. Computer

Let us learn about these tools in the given video lecture.

Digital Forensics: Imaging of hard disk and other media

Disk Imaging is a fundamental process in digital forensics. Storage devices are one of the many evidences we encounter at the crime scene. It is of prime significance that every evidence needs to be handled with care and there should not occur any alteration during the investigation of digital crime. During digital investigation, there are chances that the data collected may get intentionally or accidentally destroyed, at such times; the evidence cannot be present in the court. Investigator has to follow the proper chain of custody. To avoid changes in seized storage devices one instruction that is to be followed by investigator is “DO NOT TOUCH THE ORIGINAL EVIDENCE”, it means that we are not suppose to perform any operation related to analysis directly on original device.

In disk imaging, we make exact copies of storage devices or its partition and then store it in a larger storage or directly burn it on another device. It looks like a copy- paste operation but it is not. In copy paste operation, we just move data from one location to another location but there is no possibility that the source addressing is maintained. Also in copy-paste operation, data existing on target location is not overwritten because it is stored only in free location. Whereas in cloning or imaging data and its location is considered. In an image, file data is stored along with its source location and in cloning process data from source will be replicated as it is and old address scheme is considered.

Let us learn through the given video lecture.

Digital Forensics: Intellectual Property Crimes and Computer Security

Intellectual  property  rights  are  the  legal  rights  that  cover  the  privileges  given  to  individuals who are the owners and inventors of a work, and have created something with their intellectual creativity. Individuals related to areas such as literature, music, invention, etc., can be granted such rights, which can then be used in the trade practices by them. The originator or designer acquires exclusive privileges against any exploitation or use of work without his prior knowledge and permission. However, the rights are fixed for a limited period of time to sustain balance. Intellectual property can be pilfered (i.e., infringed or defrauded) in several ways. For example, copyrighted works,  such  as books,  music, movies,  business  software  or  games, may be dishonestly invaded by duplicating or  distributing unlicensed copies  of  such  works  either online   or   by   manufacturing   and   distributing   infringed CDs   or   DVDs   containing   the  unauthorized  content.  A trademark may be trespassed by marketing merchandises, brands or other packaging containing an imitation mark.  An exceedingly protected trade  secret  can  be underhandedly fiddled from  its  owner  either  by  a  company  insider  or  by somebody outside a company and used to profit an opponent.

Let us learn about all this in the given video lecture.

Digital Forensics: DOS and DDOS Attacks

The attacks on the computer systems are wide. It ranges from physical damaging to the system to remotely stealing the data. There are many types of attacks on computer system. Now a day’s every computer is connected to internet, and internet has no owner; it’s a kind of free resource but you have to pay for your service providers. Our software culture is also moving from standalone applications to web based/ distributed applications. The advantage of web based applications is that it is available remotely for a whole team of people to work simultaneously. So every system connected to the internet has a threat. Anyone who is connected to the internet can try to access any resource through the internet.

The basic intention behind  attacks on internet  is to make resource unavailable for the genuine users. Denial of Service (DoS) can be done by multiple ways. There are special tools available for DoS. The basic concept is that Computer Server plays vital role in distributed software’s.

Let us learn about DOS and DDOS attacks in the given video lecture.

Digital Forensics: Programme Manipulation

To get work finished by computer there are some logical/computational instructions in computer memory, this set of instructions is known as a program. There are special people known as 'Software Developers' or 'Programmers' who use available programming language to write program. After loading these programs in computer we can execute them. Basically these are instructions for CPU (Central Processing Unit) which governs the COMPUTER.

A program is developed for specific tasks, means we use ability of computer to perform a specific set of sequential actions. We can write a program to just display "Hello" or we can write a program to develop an Operating system. Size of the program is from few KB to few GB. It depends on how many functionalities we are implementing in a program.

Computer can understand only BINARY language so if we want to issue instructions to computer then they should be in BINARY language only. And binary language is a sequence of '1’s' and '0’s'. But for human it is very difficult to understand or write the program/instructions in binary. So there are options which include use of high level programming language. These languages are very close to 'English' so user can easily read or write the program. And there is another program /software which are known as Compiler or interpreter which converts the programs from higher level language to machine level language or binary language.

Let us learn in detail in the given video lecture.

Digital Forensics: Obscenity and Pornography

The concept of Obscenity is way too complicated. It is not that much easy to calculate the degrees of an obscene conduct or rather a conduct. An act which may be normal for a particular individual, community or area may not be deemed appropriate to another one. For one individual it may be a piece of art while for others it may be a nasty activity. For example, a commercial of a Condom in a national television channel may be supposed by some audience as an offensive (obscene) program while some audience may take it as the requirement of present time. A common understanding of the term ‘obscenity’ would indicate the violation of prevalent moral codes in words, representations or actions that are available to the public at large. It is basically associated with matters that contain sexually explicit material.

Pornography can be understood as sexually explicit representation which has the purpose or intention of sexually arousing its audience. Besides, paedophilic psychology has cursed the human society and modified the conventional pornography to the most displeasing disinclined involvement of children in form of Child Pornography. The term “child pornography” implies conventional pornography with child subjects. The term is retained because it is the expression most voluntarily recognized by the public on the whole. Pornographic sites open the syndicate to legal accountability by not preventing the access of such material because the technology exists.

To know more let us watch the given video.

Digital Forensics: Spamming

Spamming is the process of crowding the user’s mail inbox with unsolicited or junk mails. It is generally used to advertise about any product or services but the real problem arises for the user when the mails contain viruses and malicious software that can damage the user’s computer or data. It is often a source of scams, computer viruses and offensive content that takes up valuable time and increases costs for consumers, business and governments. Software companies offer their products for free but they need to make money in one way or another, so they use several methods to earn. One of those methods is selling ads. Many websites have banner ads or pop- up windows with advertisements in them that are visible when the software is used. Advertising companies pays the software manufacturer to place the ads in their product, allowing the software manufacturer to offer their product for free to the customer.

Let us learn more about spamming in this video lecture.