Lecture (5) Computer Crime PDF

Computer Crime Computer terms Algorithm – a structured set of rules or operations defining a logical solution to a prob- lem or a methodology to achieve some end result. An algorithm may be expressed in a flow chart. Chip – sometimes referred to as ‘silicon chip’ or, more correctly, integrated circ...

Computer Crime Computer terms Algorithm – a structured set of rules or operations defining a logical solution to a prob- lem or a methodology to achieve some end result. An algorithm may be expressed in a flow chart. Chip – sometimes referred to as ‘silicon chip’ or, more correctly, integrated circuit. A small piece of semiconducting material, such as silicon, which, with layers of conduct- ing and insulating materials, makes up a micro-electronic circuit incorporating numer- ous semiconductor devices (such as transistors, resistors and diodes). The contents of some chips are permanently fixed (called ROM chips – Read Only Memory) while the contents of others are volatile and can be changed (called RAM chips – Random Access Memory). Another form of chip is the EPROM – erasable programmable memory. The central processing unit (CPU) of a computer is contained on an integrated circuit; this chip is the ‘brains’ of the computer and carries out the machine language instructions derived from computer programs. Compiler – a program which converts a computer program written in a high-level lan- guage (source code) into machine language code (object code). The operation is known as compiling and the reverse operation, converting machine language code into a higher level language code, is known as decompiling. Computer – a programmable machine which can store, retrieve or process data automati- cally, usually electronically. Section 5(6) of the Civil Evidence Act 1968, now repealed, gave a statutory definition of a computer as ‘any device for storing or processing information’. Computer program – a series of instructions which control or condition the operation of a computer. Programs may be contained permanently in the computer, on integrated circuits, or stored on magnetic disks or tapes, or punched cards, etc. and are loaded into the computer’s memory as and when required. A legal definition of ‘computer program’ is given in the Export of Goods (Control) Order (S.I. 1989 No. 2376) as ‘a sequence of instructions to carry out a process in, or convertible into, a form executable by an elec- tronic computer and includes a microprogramme’. However, this definition should not be taken to be of general application. Most statutes having a direct bearing on com- puter law, such as the Computer Misuse Act 1990, the Copyright, Designs and Patents Act 1988 and the Data Protection Act 1998, do not attempt to define ‘computer pro- gram’. The United States Copyright Act 1976, as amended, in §101 (the definitions sec- tion) defines a computer program as ‘a set of statement or instructions to be used directly or indirectly in a computer in order to bring about a certain result’. Data and database – data comprises information, which may be stored in a computer or on computer storage media such as magnetic disks or CD-ROM. A database is a structured set of data – for example, a list of clients’ names and addresses, or a list of employees and their details – typically stored in a computer file. A database is usually associated with computer programs used to store, access, manipulate or retrieve the data contained in it. In terms of copyright and data protection, databases may also include manual systems such as a card index or set of structured paper files. A data warehouse is a massive collection of data, often obtained from various sources and pooled together to form a rich repository of information. Domain name – the name of a website, being a unique identifier of that website, for example, www.booksites.net. An e-mail address is a personal identifier placed before a website address, for example, [email protected]. Expert system – a computer system designed to provide advice at, or approaching, the level of an expert. These systems (and other similar systems known as KBS – knowl- edge-based systems or decision-support systems) usually contain knowledge in a data- base of rules and facts and details of the internal structure of the knowledge, an inference engine which manipulates and resolves an enquiry from a user, together with a user interface to control interaction with the user including the ability to provide jus- tifications for any advice suggested by the system. The thought of developing expert systems looked very exciting some years ago but, generally, they failed to meet the expectations of researchers in the field. Decision-support and automated decision- taking systems are commonly used though lacking the refinement and sophistication of expert systems. Hacker – a computer hacker now means a person who gains access to a computer system without permission, usually by guessing or surreptitiously discovering which passwords will allow him access. A hacker may simply inspect the contents of the system he has ‘broken into’ or may go on to alter or erase information stored in the system or place a computer virus on the system. ‘Computer hacker’ used to mean a person who was very enthusiastic about computers and who would spend most of his waking hours at a computer terminal. Hardware – the physical pieces of equipment in a computer system; for example, a computer, printer, monitor and disk drive. Hardware devices usually incorporate soft- ware. High-level language – a programming language which is relatively remote from the computer’s machine language. A high-level language statement is equivalent to several machine language instructions. High-level languages often resemble a mixture of writ- ten English and conventional mathematical notation and are easier to use for writing and developing computer programs than are low-level languages or machine language. A program in a high-level language is often referred to as a source code program. Examples of high-level languages are BASIC, COBOL, FORTRAN, PASCAL and C. Low-level language – a programming language which is very close to the computer’s machine language. Each instruction in a low-level language has a direct equivalent in machine language. Machine language – the set of instructions and statements which control the computer directly. Many computer programs are written in high-level languages and have to be converted into machine language code by the use of an interpreter or compiler pro- gram. Operating system – a program or set of programs which control and organise the oper- ation of applications programs in addition to managing memory and providing certain facilities such as loading, saving, deleting files, etc. An operating system sets up the computer so that applications programs, such as word processing and spreadsheet pro- grams, can be used. Examples are UNIX and Microsoft Windows. Software – software includes computer programs and data stored in a computer, preparatory design materials and also associated documentation such as user guides and manuals. Software may be obtained ‘off-the-shelf’, as in the case of popular word processing and spreadsheet packages, or it may be specially written or adapted for a client (‘bespoke’ software). Applications software is software designed to perform a particular applied function required by the user such as word processing, the prep- aration of accounts, the design and use of a database or the preparation of a drawing. In contrast, operating system software provides the basic platform upon which appli- cations software can operate. Spam – unsolicited e-mails, often described as junk e-mails. It is thought that the name derives from the famous Monty Python sketch about Spam (a tinned meat product con- taining mainly ham, originally an abbreviation of ‘spiced ham’). Virus – a program that attaches to other programs and files and is self-replicating and causes damage to computer programs and files. Easily transmitted from computer to computer, often as an e-mail attachment. The damage caused can be considerable with files and programs deleted or modifications made to operating system programs causing a computer to continually crash. Some viruses are specially written to take advantage of weaknesses in operating systems to spread themselves. Some have been spread by auto- matically forwarding themselves to all the addresses in a person’s e-mail address book. Lecture (3) LOW (3): Computer Informatics Basics Data is information such as facts and numbers used to analyze something or make decisions. Computer data is information in a form that can be processed by a computer. Information is knowledge that you get about someone or something : details about a subject Input: any information or data that is sent to a computer for processing. It is often sent to the computer from a device such as a keyboard, mouse, or another device Output: Any information processed by and sent from a computer or electronic device is considered output.  Systems Analysis and Design What is it? A system is a collection or arrangement of different components which not only work in combination and are interrelated in one way or the other, but also collectively perform a function. Systems analysis Process of studying an existing system to determine how it works and how it meets user needs Systems design Process of developing a plan for an improved system, based upon the results of the systems analysis 3  Systems Specialist Professional computer employee who performs analysis and design Typical career path – Programmer – Designer – Systems Analyst 4  Systems Analyst Functions Coordination Schedules and system-related tasks Personnel Communication – Oral presentations – Written documentation Planning and design – Plans and designs new system – Involved from beginning of project through final implementation of the system 5  Project Phases Planning (Why build the system? How should the team go about building it?) Analysis (Who uses system, what will it do, where and when will the system be used?) Design (How will the system work?) Implementation (System delivery) 6  Planning Identifying business value Analyze feasibility Develop work plan Staff the project Control and direct project 7  Analysis Analysis strategy Gathering business requirements Requirements definition use cases Process modeling Data modeling 8  Design Design selection Architecture design Interface design Data storage design Program design 9  Implementation Construction – Program building – Program and system testing Installation – Conversion marketing strategy: focuses on increasing the percentage of site visitors who perform a specific action , called a conversion. – Training plan – Support plan 10  SDLC Systems Development Life Cycle Preliminary investigation Analysis Design Development Implementation 11  SDLC : Preliminary Investigation Feasibility study / System survey Determine the problem Describe the problem Understand management decisions – Organizational chart – Informal hierarchy Produces rough plan and what to do Report  What you have found  Recommendations  Financially feasible 12  Goal of Preliminary Investigation Problem Definition Nature of the problem Separate problem from symptoms of problem Scope of the project Budget and schedule Objectives of the project What user thinks system should do 13 SDLC : Analysis Understand the existing system – Gather data – Analyze data Establish system requirements 14  Analysis – Data Gathering Written documents Interviews – Structured – Unstructured Questionnaires Observation – Visits by appointment – Participant observation Sampling 15  Analysis – Analyze Data How the current system works Determine system requirements Tools – Data flow diagram (DFD) – Decision tables 16  SDLC Analysis – Data Flow Diagram 17  SDLC Analysis –Decision Tables CIL Test Study material 18  Analysis – System Requirements Detailed list of things the system must be able to do Design is based upon system requirements Agreement upon requirements is needed before proceeding 19  Analysis – Report to Management Summarize problems Describe requirements Cost analysis Recommendations for next step Obtain authorization to proceed 20 SDLC : Design Planning the new system Two phases – Preliminary design – Detail design 21  Preliminary Design Create an overall plan Offer alternatives that meet requirements Explain differences Evaluate costs 22  Preliminary Design Build a prototype – Limited working system of subset – Output looks like anticipated system output Prototype: working model that can be modified and fine-tuned, Uses high-level software tools – CASE (Computer-Aided Software Engineering). It supports specific analysis and design tasks 23  Detail design Presentation All alternatives Selected plan Prototype of the system Obtain authorization to proceed 24 Lecture (2) LOW (2): Software Component Operating systems software The operating system is a special type of program that loads automatically when you start your computer. The operating system allows you to use the advanced features of a modern computer without having to learn all the details of how the hardware works The link between the hardware and you, the user Makes the computer easy to use without having to understand bits and bytes! each character can be 16 bits (2 bytes) or 32 bits (4 bytes). All UTFs include the full Unicode character repertoire , or set of characters Software Component Applications software An application program is the type of program that you use once the operating system has been loaded. Examples include word-processing programs, spreadsheets and databases Software Component Application Software Word processing applications Microsoft Word Lotus Word Pro WordPerfect Spreadsheets Microsoft Excel Lotus 123 Database Microsoft Access Lotus Approach Software Component Application Software Payroll Sage software Presentation tools Microsoft PowerPoint Lotus Freelance Desktop publishing Abode Photoshop Multimedia applications Microsoft's Encarta CD-ROM based encyclopaedias Information Network LAN A LAN (Local Area Network) is a system whereby individual PCs are connected together within a company or organization WA N A WAN (Wide Area Network) as the name implies allows you to connect to other computers over a wider area (i.e. the whole world). Information Network Uses of Network If ten people are working together within an office it makes sense for them all to be connected. In this way the office can have a single printer and all ten people can print to it. In a similar way other devices such as modems or scanners can be shared. Even more useful is the ability to share information when connected to a network. Computer Accessories Modem Short for “MODulate/DEModulate”. The modem sends information from your computer across the telephone system. The modem at the other end of the phone line, converts the signal back into a format that can be used by the receiving computer. Uses of Computer PC at Home Common uses for the computer within the home Computer games Working from Home Banking from Home Connecting to the Web Uses of Computer Computers in Education CBT (Computer Based Training) Computer Based Training (CBT) offers a low cost solution to training needs where you need to train a large amount of people on a single subject. These programs are normally supplied on CD-ROM and combine text, graphics and sound. Packages range from general encyclopaedias right through to learning a foreign language. Uses of Computer Office Applications Automated Production Systems Many car factories are almost completely automated and the cars are assembled by computer-controlled robots. This automation is becoming increasingly common throughout industry. Design Systems Many products are designed using CAD (Computer Aided Design) programs to produce exact specifications and detailed drawings on the computer before producing models of new products. Uses of Computer Office Applications Stock Control Stock control is ideal for automation and in many companies it is now completely computerized. The stock control system keeps track of the number of items in stock and can automatically order replacement items when required. Accounts / Payroll In most large organizations the accounts are maintained by a computerized system. Due to the repetitive nature of accounts a computer system is ideally suited to this task and accuracy is guaranteed. Uses of Computer Computers in Daily Life Accounts Games Educational On-line banking Smart ID cards Supermarkets Working from home (Tele-working) Internet Create a Good Working Environment Frequent breaks away from the computer Appropriate positioning of screens, chairs and keyboards Provision of adequate lighting and ventilation. Health & Safety Precautions Make sure that cables are safely secured Make sure that power points are not overloaded Also be aware of: Repetitive Strain Injury (RSI) Glare from screens Bad posture Value of Backup The most important thing that you store on your computer is information. Often the contents of a hard disk can represent years of work. If the hard disk stops working one day you could lose all those years of work. For this reason it is VITAL that you take regular backups of the information that is stored on the computer. Value of Backup Organize your computer for more efficient backups Complete vs. incremental backups Use 'off-site' storage Value of Backup Use passwords Understand the Importance of shutting down your computer properly Use a UPS (Un-interruptible Power Supply) Likes & Dislikes of Computer Things computer like: Good ventilation Clean environment Stable, vibration free surface Things computer don’t like: Dust Drinking and eating over the keyboard Heat, Cold or Moisture Don’t place objects on top of monitors. Don’t place floppy disks near monitors. Computer Virus What are computer viruses? Viruses are small programs that hide themselves on your disks (both diskettes and your hard disk). Unless you use virus detection software the first time that you know that you have a virus is when it activates. Different viruses are activated in different ways. Computer Virus H o w do viruses infect PCs? Viruses hide on a disk and when you access the disk (either a diskette or another hard disk over a network) the virus program will start and infect your computer. The worst thing about a computer virus is that they can spread from one computer to another, either via use of infected floppy disk, or over a computer network, including the Internet. Computer Virus H o w to prevent virus damage There are a number of third party anti- virus products available. Most of these are better than the rather rudimentary/traditional products available within DOS and Windows, but of course you do have to pay for them! The main thing about your virus checker is that it should be kept up to date. Many companies supply updated disks on a regular basis or allow you to receive updates through an electronic, on-line bulletin board. Software Copyright What about software that you find on the Internet? Be aware on software copyright issues 1. Freeware 2. Shareware Freeware software is provided to its users free of cost. Shareware software is provided to its users free for a limited period of time after which software needs to be paid. 3. Software with licenses Software Copyright If your computer system holds information about individuals then you have a moral and legal duty to treat that information with respect. In a free society you have a right to ensure that information held about you is not abused. In many countries this right is enshrined under data protection laws Thank you