Computer Science Theory

What's phishing?

Email, with a hyperlink to a fake website

Why do some websites ask to accept 'cookies'?

Enable login information to be stored so it's 'remembered', so that the website distinguishes between new and repeated visitors

How does HTTP provide security?

By using some form of encryption so that the data cannot be accessed by anybody other than the user and the web server

Danger of phishing?

Can gain personal data like bank account numbers, fraud or identity theft

Description of address bus?

Carries signals relating to addresses between the processor and memory

Description of control bus?

Carries signals relating to the control and coordination of all activities within the computer

Dangers of viruses?

Causes the computer to crash, malfunction or become unresponsive. Can delete and corrupt files

Check type: range?

Check whether data is within a given and acceptable range of values

Check type: format (picture)?

Checks data is in a specified format or template

Check type: consistency?

Checks if linked fields correspond with each other and there are no data conflicts taking place

Check type: character (type)?

Checks the input data does not contain any incorrect characters

Check type: presence?

Checks to see whether any data has in fact been entered

Check type: length?

Checks whether input data contains the required number of characters

What happens in an ARQ if the sender does not receive an acknowledgement before the timeout?

Data is usually re transmitted automatically until it is acknowledged

Danger of pharming?

Fraud, identity theft. Gain personal data like bank account numbers.

The 3 sections that make up the URL?

Protocol (http), web server's name (www.google.com) and file name (/search3892

Application of OMR?

Reading pencil marks on a questionnaire

Give an example of software interrupt

Program tries to divide by 0

1 KB in bytes?

2^10 bytes

1MB in bytes?

2^20 bytes

1GB in bytes?

2^30 bytes

1TB in bytes?

2^40 bytes

1PB in bytes?

2^50 bytes

What is HTML?

A markup language, allowing the display of a document on a website. This can be identified if the URL at the end shows .htm .html

What exactly are cookies?

A packet of information sent by a web server to a web browser.

What does ISP do?

A portal that a company provides so that the user gains access to the Internet

What is a protocol?

A set of rules for doing something

What is a buffer?

A short term memory storage usually composed of RAM chips

What is an interrupt?

A signal sent from a device/running program to the processor, which causes it to stop what it was doing and service the interrupt signal

What is a MAC address?

A unique address that is given to every piece of hardware. It's embedded in the hardware when the product is made in a factory.

What is a virus?

Program or program code that can replicate itself with bad intentions

Name the three buses in computer architecture?

Address bus, data bus and control bus

What is IP address?

An address that uniquely identifies every computer connected to an IP based network. This includes a 32 bit number, 4, 3-digit numbers deprecated by dot.

Check type: check?

An extra digit is added to a number which is calculated from the other digits; the computer recalculated the check digit after the number has been input

What is ADC?

Analogue to digital converter

How to guard against pharming?

Anti-spyware software which removes the code from hard drive. User should be alert and look out for clues that they are being redirected to another website.

What does ARQ stand for and what is it?

Automatic Repeat reQuest. An error-control method that uses acknowledgements and timeouts

Application of data logger?

Automatic recording of data monitoring conditions in a river

Application of MICR?

Bank system reading and processing cheques

How to guard against phishing?

Be cautious in opening emails, most ISPs filter out phishing emails as spam

Data/signal direction of data bus?

Bi-directional

Definition of hacking?

Gaining illegal access to a computer system without the user's consent

Dangers of spyware/key-logging software?

Gives access to all data entered. The software is able to install other spyware, read cookie data and change a user's default browser

Dangers of wardriving?

Gives the possibility to hack into the wireless network and steal a user's password and other personal details. User's Internet time/allocation stolen

What does HTML stand for?

HyperText Markup Language

What does HTTP stand for?

HyperText transfer protocol

Danger of hacking?

Identity theft, stealing personal information. Data can be changed, deleted, corrupted.

How to guard against viruses?

Install anti-virus software, don't use software from unknown resources, be careful when opening emails/attachments from unknown senders

What does IP stand for?

Internet Protocol Address

What does ISP stand for?

Internet Service Provider

How is a MAC address usually written?

It's a 48 bit number, usually written as 12 hexadecimal characters

MICR

Magnetic Ink Character Reader

What is pharming?

Malicious code installed on a user's hard drive or on the web server, automatic redirect to a fake website without user's knowledge

What does MAC address stand for?

Media Access Control

OMR

Optical Mark Readers

Name three error checking methods

Parity check, checksum and ARQ

What happens once the interrupt signal is received?

Professors carries on with what it was doing or stops to service the device/program that generated the interrupt

Description of data bus?

Sends data between processor, memory unit and input/output devises

What is HTTP?

Set of rules for transferring files over the web, can be used to allow more secure transactions like bank transfers.

Check type: limit?

Similar to range check except only one of the boundaries is checked

What is a web browser?

Software that allows the user to display and interact with web pages and files from the internet

What is spyware/key-logging software?

Software that gathers information by monitoring key presses on user's keyboard

What does a printer buffer do?

Store data temporarily until the device is able to process the data

What do buffers allow?

The professor to perform other tasks simultaneously

Data/signal direction of address bus?

Unidirectional

Data/signal direction of control bus?

Unidirectional

What does URL stand for?

Uniform Resource Locator

How to guard against wardriving?

Use of Wired Equivalent Privacy (WEP) encryption, having complex passwords, use of firewalls

How to guard against hacking?

Use of anti-hacking software, firewall, use of strong passwords and user ID

How to guard against spyware/key-logging software?

Use of anti-spyware software. User should lookout for clues. Using a mouse to select characters from passwords rather than typing

Application of biometrics?

Use of finger printing in a security system

Give an example of user interrupt

User presses the <break> key

What is wardriving?

Using wireless internet connections illegally