Security

Question 1

Computer security

Answer 1

The protection of computers form unauthorised access and the protection from data loss.

Question 2

How to prevent unintentional loss of data

Answer 2

• Backup of data help to retrieve data when it is lost

- Verification helps to prevent data loss occurring

Question 3

Backups

Answer 3

Is a copy of data being used that we can keep in case of data loss. The data is copied on separate storage medium.

Question 4

Where to back up data?

Answer 4

• magnetic media-external hard disk drive or magnetic tapes
• optical media-CD, DVD, Blue-ray disks
• cloud storage-online back up facilities

Question 5

Verification

Answer 5

Is a check that asks the user to confirm whether or not he wishes to go ahead with the instruction.

Question 6

When the verification is used?

Answer 6

• when attempting to save a file with a filename that already exists in that location
• when deleting a record or file

Question 7

Types of attacks

Answer 7

• malware
• phishing
• pharming
• denial of device (DoS) attack

Question 8

Types of malware

Answer 8

• viruses
• worms
• trojan horses
• spyware

Question 9

Worms

Answer 9

They replicate themselves over and over, filling the computer’s storage. This can cause a computer to run slowly or stop running.

Question 10

Trojan

Answer 10

Programs that disguise themselves as other programs. When run, they act like any other virus, deleting and corrupting files.

Question 11

Phishing

Answer 11

Attack usually comes in the form of email. The email will look person or organisation that is known and trusted by the user. It is designed to trick user into giving data such as passwords.

Question 12

Pharming

Answer 12

Attempts to trick the user into giving their personal data by using fake websites. When a user tries to visit a genuine website, they instead re-direct to a fake website that looks almost same.

Question 13

How does pharming work?

Answer 13

Malware installed on the user’s computer look for domain names of reputable sites and translates them into different IP addresses those of fake websites.

Question 14

DoS attacks

Answer 14

Denial of Service. These attacks are not designed to gain access to data but instead they prevent access to data.

Question 15

How does DoS attack work?

Answer 15

It attempts to prevent access to a server by sending it more requests than it can handle. The request queue becomes so large that the server cannot respond to all requests within a reasonable time.

Question 16

Physical security

Answer 16

Security that prevents a physical access to a computer.
E.g.
Locks-computers can be kept in locked room
CCTV-cameras can be used to monitor who physically accesses a computer.
Security guards-extra level of security to help deter unauthorised people.

Question 17

Authentication

Answer 17

Is designed to stop a user from being able to access the system once they have physically got to it. Also, when hacker is trying to get access trough internet.

Question 18

Biometrics

Answer 18

As physical characteristics are unique, they provide a way to identify a user to a computer. It uses scanners or sensors to record input.

Question 19

Proxy servers

Answer 19

One way to protect a network server from attacks is to prevent direct access to the server itself. This is done by directing traffic to an intermediary server. The proxy server sits between the network server and the internet.

Question 20

Benefits of proxy servers

Answer 20

• if the data are lost on proxy server, the original data are still held on server network
• as a proxy server can handle requests and transfer data, the network server is free and faster
• can hold copies of frequently visited webpages. This speeds up access to those pages, since the webpages do not have to be downloaded again
• can be used to prevent users on a network from accessing external websites

Question 21

Encryption

Answer 21

A way of modifying data to make it difficult to understand by unauthorised person.

Question 22

Key

Answer 22

Information that describes how a massage is encrypted or decrypted.

Question 23

SSL

Answer 23

Secure Socket Layer. It uses asymmetric encryption to create a secure links between computers, so data can be transferred safely.

Question 24

TSL

Answer 24

Transport layer security. More recent, updated version of SSL. It works the same way as SSL.