Questioned Documents: Secret Writing

Secret Writing: Cryptography, Encrypt- Decrypt, Steganography

All the way through history, military had used secure communications through encryption of the data. It was in 1980’s that the need for secure commercial and private communications had grown under the name of the Information Age. Internet and the World Wide Web is a platform that allows community to correspond information, mail and commerce in a digital medium. This has caused in an augment in the need for information security.

Historical Cryptography

• Ancient Egypt
• Greece
• Rome
• Alberti- Vigenere Cipher
• Jefferson Wheel Cipher

War Driven Cryptography- WWI

• Zimmerman Telegram
• Choctaw Codetalkers

War Driven Cryptography- WWII

• Enigma Encryption Machine
• Purple

 Modern Encryption- Part 1

•  One-time Pad
• Pseudo-Random Number Generator
• Symmetric Key Encryption (Private-Key)

Modern Encryption- Part 2

• Asymmetric key Encryption (Public-Key)
• Diffie-Hellman Key Exchange
• RSA Encryption

Steganography

Let us learn about all this in detail through this video lecture.

Criminology 4: Social, Political and Organized Crimes

A crime can be well-defined as any act that is against laws or the legal justice system. There are various kinds of crimes, from crimes towards individuals to victimless crimes and violent crimes to white collar crimes. With every form of offence there also originates different sociological phenomena and demographic profiles.

Crimes against Persons: Crimes towards persons, also known as private crimes, comprise homicide, serious assault, sexual assault, and burglary. Personal crimes are disproportionately spread in the United States, with young, urban, poor, and racial sections doing these offenses more often than others.

Crimes against Property:  Property crimes comprise robbery of property deprived of bodily harm, such as burglary, larceny, auto theft, and arson. Like personal offenses, young, urban, poor, and racial minorities usually commit these offenses more than others.

Crimes against Morality: Crimes against ethics are also known victimless crimes because there is no petitioner, or victim. Prostitution, illegal gambling, and prohibited drug intake are all examples of victimless crimes.

White-Collar Crimes: White-collar crimes are offences that are done by individuals of good social position who commit offences in the relation to their profession. This comprises cheating (robbery of money from one’s employer), insider trading, and tax evasion and other abuses of income tax laws. White-collar crimes generally produce less anxiety in the public mind than other kinds of crime, though in relations of full dollars, white-collar crimes are even more significant for society. Nevertheless, these offenses are usually the least inspected and less accused.

For more details go through the given video lecture.

Digital Forensics : Operating Systems

An Operating System is a program which performances as an interface between the computer system users and the computer hardware components. It displays for a comprehensible setting in which a user may effortlessly develop and execute programs. Else, hardware knowledge would be compulsory for computer programming. Operating Systems obscures the complexity of hardware from apathetic users. The Operating Systems accomplishes resources and distributes them to specific programs and users. With the management of the Operating Systems, a programmer is cleared of difficult hardware deliberations. Operating Systems affords services for:

• Processor Management 
• Memory Management 
• File Management 
• Device Management 
• Concurrency Control  

A running program does one very simple thing, i.e., it executes instructions. Billions of times every second, the processor procures instructions from memory, decodes it, and executes it. After it is finished with this instruction, the processor moves on to the next instruction, and so on, until the program finally concludes. There is a body of software, in actual fact that is in control for making it easy to run programs, allowing programs to share memory, facilitating programs to interact with devices. That body of software is known as the Operating System (OS), as it is in charge of making sure the system operates appropriately and proficiently in an easy-to-use manner.

Drugs of Abuse: Designer Drugs

Over ages, humans fortunately discovered that certain ingested plants were a source of unique satisfying feelings, beyond satiety. Some were mildly affecting (e.g. nicotine, caffeine), others enhanced mood or altered perception, reduced pain, intoxicated, or produced euphoria (e.g. alcohol, marijuana, hallucinogens, opiates, cocaine). In the past two centuries, consumption of these psychoactive substances expanded rapidly. Decontamination of the active chemicals, distribution by manoeuvres for maximum effect and global marketing contributed to this expansion. Modern chemistry has produced a huge range of variations of these plant products, paralleled by an unprecedented level of adverse biological, behavioral, medical and social consequences. Following this phenomenon, Designer drugs are produced to be similar to, but not identical with Psychoactive Drugs that are illegal to possess or sell for human consumption, unless for medical purposes. A recurring threat to public health, the Designer Drug sub-culture has burst out over the past decade. The rapid expansion can be attributed to a convergence of crucial technological advances combined with deceitful, aggressive marketing schemes.

Digital Forensics: Computer Software

Computer cannot do anything on its own. It is the user who instructs computer; what to do, how to do and when to do. In order to perform any task, a set of instructions in a particular sequence is given to the computer. These sets of instructions are called Programs. Software refers to a set of programs that makes the hardware perform a particular set of tasks in particular order. Software not only gives directions  to the computer to manage its internal resources, but also facilitates the user to use a computer system to provide specific business value. The computer is able to do nothing until it is instructed by software. Although computer hardware is, by design, wide-ranging purpose, software allows the user to instruct a computer system to execute specific functions that deliver business value. The systems software existing on a computer system provides the competences and restrictions within which the application software can function. If a computer is to function, software is not optional. Everything that a computer does, from the time the power switch is turned on until the system is shut down, is under the control of software. Basically, Software is the set of instructions that operate the computer, execute particular functions or tasks, and manipulate the data. For software (the instructions) to perform various functions, it must be programmed. That is, the instructions need to be written in a programming language that the computer can understand. Without a program, a computer is useless. 

Software can be either ‘proprietary’ (also called ‘closed’) or ‘open’. Proprietary software is privately maintained and controlled. A proprietary software scheme or technique is one that is held by a company, which will generally not disclose specifications that would let other companies to replicate the product. Gradually, proprietary software is seen as a drawback in several institutes; users have a preference to use ‘open’ software, which is software designed exhausting specifications that are widely accessible. The benefit of open software is that any person can make add-on products for it as they can appreciate in what manner it was designed. People using open software can mix and match products from different manufacturers. By making software public, however, a manufacturer permits others to duplicate its product, which many manufacturers do not want.

To know more details about the Computer Software watch the given video lecture.

Drugs of Abuse: Natural Drugs

NATURAL DRUGS

For thousands of years, natural products have played a very significant role in health care and prevention of diseases. The prehistoric civilizations of the Indians, Chinese and North Africans provide inscribed evidence for the use of natural sources for curing many diseases. Conventional natural product chemistry approaches facilitated a vast selection of bio-active secondary metabolites from terrestrial and marine sources to be discovered. 

Natural products have been the most effective source of potential drug leads. Natural products once assisted humanity as the source of all drugs, and higher plants provided most of these therapeutic agents. 

However, it was not until the 19th century that scientists isolated active components from various medicinal plants. 

• Friedrich Serturner isolated morphine from Papaver somniferum in 1806, and since then natural products have been widely selected for their medicinal purposes. 
• Atropine obtained from Atropa belladonna, strychnine, a Central Nervous System stimulant,
• Ziconotide, identified from a cone snail, Conus magus, and Taxol are a few examples of active components taken out from natural sources. 

Drug detection from the usual sources mostly involves two methodologies, principal one is chemically determined which is discovery natural activities for disinfected complexes and second is the biologically driven in which bioassay‐guided approach starts with crude extracts or it can be combination of the both. Natural product chemistry is one of the oldest branches of the chemical sciences, its origin dating back to the first decades of the 19th century, or even before. 

Natural Products act as lead molecules for the synthesis of various potent drugs. Natural products entities depend not only on plants but also on other form of life like algae, fungus, sponges, molluscs, etc. Microorganisms have been widely screened for antibiotics since Fleming’s discovery of the antibacterial activity of Penicillium.

Let us learn about more Natural Drugs in the given video lecture

Criminology 3: Types of Crime

"Crime is an activity that breaks the law and enforcement”. Crime is not the problem of one home or one person; it is the problem of whole society. It costs not only in currency every year but also represents an  even  greater  loss  in  terms  of  human  values,  happiness and their morals. In recent years the crime graph is more appalling not only in India but all over the world.

According to the legal definition crime “implies any act done or committed in violation of   public   law,   and   for which the   person   is   liable to   punishment   by   indictment, presentment or impeachment”.  Crime is a universal   phenomenon.   Its   etiology   is extremely complex and the manifestations vary according to time, place and the individual. It also varies with historical periods, modes of life, economic conditions and social attitudes. 

Crime  has  been  with  mankind  since  the  beginning  of  recorded  history.  Ever  since  man has attempted to find the most effective deterrents against crime, society has framed the theories of punishment and established the prison system to control the criminal behavior but crime has continued unabated. The idea of a crime free society is utopian. Thus, the researchers suggest that we should place emphasis on prevention of crime.

Let us learn about the various types of crimes through this given video lecture.