DEALING WITH WHITE COLLAR CRIME

COMPUTER CRIME & THE USE OF COMPUTERS IN CRIME

Generic overview of a computer system

The generic overview describes some of the terms that are used in computing and shows how they all relate to each other. Understanding these terms and their relationships is important because many of the risks and controls discussed later on arise from the items that are found on a computer and the way that it is structured.

General concepts

A computer system comprises 'hardware', 'software' and 'data'.

'Hardware' refers to the physical components of the computer such as the keyboard, disks and a processor.

'Software, refers to the programmes that run on hardware and generally comprises two classes:

• 'Operating system software', which controls the way that the hardware operates and communicates with other computers.
• 'Application software' which is the software that will be operated by the users of the system, typically this would be accounting packages, spreadsheets, word processing, databases, stock control and, in the case of financial organisations, loans and savings accounts.

'Data' is an expression that refers to the information used by application software. Taking the recording of a cash receipt into a cash book system as an example; the application software records a receipt of cash into a file containing all the receipts. The collective name for all those files and their contents is the 'data' held by the computer.

All that has been said previously could be represented in a simple diagram

Naturally, users operate the system through keyboards and screens but they actually use the application software to achieve their business objectives.

Internal Structures

Internally, a computer is structured around a number of components each of which are designed to achieve specific tasks:

Hard disk - this is the area where application software, data and the operating system is stored;

Processor - the device that carries out all the instructions issued by the software, often referred to as the CPU (Central Processor Unit).

Memory - a number of microchips that contain information used by the processor (the processor does not operate on information held on the hard disk but calls in the information from disk to memory before using it).

Once again, this could be shown diagrammatically as follows:

From the diagram you'll note that all of the information relating to the computer system, and much of the information concerning your business, is stored on the hard disk. Given this, it is easy to see why access to the disk and the information it contains should be controlled. Much of what is discussed later on will build on this need to control access to the disk.

Before progressing further, it is important to realise that the information stored on a disk is not simply randomly stored, rather it is organised into groups known as directories. There are special directories for storing the programmes forming the operating system, the application software and the data used by the application software.

Networks

Frequently a business will require that more than one computer be used, possibly because of large numbers of users or high volumes of transactions going through the system. Because the business will want to be able to gain access to all it's data, it will frequently connect the computers together using cables or telephone lines. This arrangement is known as networking.

Networks can be small (three computers linked together on one floor of a building) or large (where computers around the world are linked together).

Organisation and staff

In simple computer systems, such as the one you might have on your desktop, you look after the applications, the operating system and the data. In bigger systems this is not possible because the applications, the operating system and the data used are much more complex. Consequently, specialists are employed to manage these aspects of a larger computer system. Groups of specialists deal with the operating system, the application software and manage the storage of data. You are probably familiar with some of these specialists:

Programmers are skilled in writing and modifying programs that access and change the data stored on the computer systems.

Systems software specialists assume responsibility for ensuring that the operating system works as efficiently as possible.

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