Sunday, February 22, 2009

Form 4: 1.3.1.1 - Define computer security

COMPUTER SECURITY

DEFINITION OF COMPUTER SECURITY
Computer security means protecting our computer systems and the information they contain against unwanted access, damage, destruction or modification.

We need to protect our computer from any intruders such as hackers, crackers and script kiddie.
We do not want strangers to read our e-mail, use our computer to
attack other systems, send forged e-mail from our computer, or examine personal information stored on our computer such as financial statements.

  • TYPES OF COMPUTER SECURITY
    Three types of computer security are:

    a) hardware security
    b) software security/data security
    c) network security


    a) HARDWARE SECURITY
    Hardware security refers to security measures used to protect the hardware specifically the computer and its related documents.

    The examples of security measures used to protect the hardware include PC-locks, keyboard-locks, smart cards and biometric devices.

    b) SOFTWARE AND DATA SECURITY
    Software and data security refers to the security measures used to protect the software and the loss of data files.

    Examples of security measures used to protect the software are activation code and serial number.

    An example of security measure used to protect the loss of data files is the disaster recovery plan method. The idea of this plan is to store data, program and other important documents in a safe place that will not be affected by any major destruction.

    c) NETWORK SECURITY
    The transfer of data through network has become a common practice and the need to implement network security has become significant.

    Network security refers to security measures used to protect the network system. One example of network security measures is firewall. With firewall, network resources can be protected from the outsiders.

    PERSONAL COMPUTER SECURITY CHECKLIST
    In order to make sure our computers are secured, here are the computer
    security checklist to follow.

    ü Do not eat, drink or smoke near the computer
    ü Do not place the computer near open windows or doors
    ü Do not subject the computer to extreme temperatures
    ü Clean the equipment regularly
    ü Place a cable lock on the computer
    ü Use a surge protector
    ü Store disks properly in a locked container
    ü Maintain backup copies of all files
    ü Stores copies of critical files off sites
    ü Scan a floppy disk before you open it
    ü Do not open any unknown email received

    1.3.2.1 - Explain briefly the different threats to computer
    security :
    Malicious code
    Hacking
    Nature/environment
    Theft


    INTRODUCTION COMPUTER THREATS

    The computer is a great tool to store important information. In certain cases, the information is very vital that losing it will harm the computer system.

    Computer threats can come from many ways either from human or natural disasters. For example, when someone is stealing your account information from a trusted bank, this threat is considered as a human threat. However, when your computer is soaked in heavy rain, then that is a natural disaster threat.

    MALICIOUS CODE
    Malicious code is also known as a rogue program. It is a threat to computing assets by causing undesired effects in the programmer’s part. The effect is caused by an agent, with the intention to cause damage.

    The agent for malicious code is the writer of the code, or any person who causes its distribution. There are various kinds of malicious code. They include virus, Trojan horse, logic door, trapdoor and backdoor, worm and many others.


    a) VIRUS
    · a program that can pass on the malicious code to other programs by modifying them

    · attaches itself to the program, usually files with .doc, .xls and .exe extensions

    · destroys or co-exists with the program

    · can overtake the entire computing system and spread to other systems

    b) TROJAN HORSE
    · a program which can perform useful and unexpected action

    · must be installed by users or intruders before it can affect the system’s assets

    · an example of a Trojan horse is the login script that requests for users’ login ID and password

    · the information is then used for malicious purposes

    c) LOGIC BOMB
    · logic bomb is a malicious code that goes off when a specific condition occurs.

    · an example of a logic bomb is the time bomb

    · it goes off and causes threats at a specified time or date

    e) TRAPDOOR OR BACKDOOR
    · a feature in a program that allows someone to access the program with special privileges

    f) WORM
    · a program that copies and spreads itself through a network


    HACKER
    Hacking is a source of threat to security in computer. It is defined as unauthorised access to the computer system by a hacker.

    Hackers are persons who learn about the computer system in detail. They write program referred to as hacks. Hackers may use a modem or cable to hack the targeted computers.

    NATURAL AND ENVIRONMENTAL THREATS
    Computers are also threatened by natural or environmental disaster. Be it at home, stores, offices and also automobiles.Examples of natural and environmental disasters:
    Flood
    Fire
    Earthquakes, storms and tornados
    Excessive Heat
    Inadequate Power Supply

Primary Differences Between Worms And viruses


Worm
Operates through the network
Spreads copies of itself as a standalone program


Virus
Spreads through any medium
Spreads copies of itself as a program that attaches to other
programs

THEFT
Two types of computer theft:

1) Computer is used to steal money, goods, information and resources.
2) Stealing of computer, especially notebook and PDAs.

Three approaches to prevent theft:

1) prevent access by using locks, smart-card or password
2) prevent portability by restricting the hardware from being moved
3) detect and guard all exits and record any hardware transported






















THEFT
Two types of computer theft:

1) Computer is used to steal money, goods, information and resources.
2) Stealing of computer, especially notebook and PDAs.

Three approaches to prevent theft:

1) prevent access by using locks, smart-card or password
2) prevent portability by restricting the hardware from being moved
3) detect and guard all exits and record any hardware transported