Section 10 Chapter 58 - Internet Security

Question 1

Firewall

Answer 1

A security checkpoint that prevents unauthorised access between two networks, often a local network and the internet

Question 2

The uses firewalls (3)

Answer 2

• Packet filtering
• Stateful inspection
• Proxy server

Question 3

Packet filtering

Answer 3

Controls network access by rejecting certain packets based on the contents of their header. It can look at the

Question 4

Stateful inspection

Answer 4

Controls network access by inspecting the payload of packets. It can apply temporary rules based on the passage of previous packets in a conversation

Question 5

Proxy server

Answer 5

Intercepts all packets entering and leaving a network and therefore hides the true network addresses from the recipient. It can also store a cache of recently viewed webpages to increase browsing speed

Question 6

Encryption

Answer 6

The process of scrambling data so that it can only be read with the correct key

Question 7

The type of key for symmetric encryption

Answer 7

private

Question 8

Symmetric encryption

Answer 8

The same key is used to encrypt and decrypt the data.

Question 9

Type of key for asymmetric encryption

Answer 9

public and private

Question 10

Asymmetric encryption

Answer 10

There are two keys: public and private. The public key is used to encrypt and the private key is used to decrypt. Anyone can encrypt a message with the public key but only you can read it using your private key

Question 11

How digital signatures work

Answer 11

A checksum is appended to the end of some data. This is then encrypted using the senders private key. When received, the checksum can be obtained by decryption through the use of the senders public key and then can be checked against the data. The signature may contain the time and date

Question 12

Digital certificate

Answer 12

Issued by the Certificate Authorities and verifies that the public key for a digital signature is formally registered.

Question 13

Worm

Answer 13

Standalone malware that can replicate itself and spread

Question 14

Virus

Answer 14

Malware that requires a host to spread and replicate itself

Question 15

Trojan

Answer 15

Malware that disguises itself as a legitimate program. Cannot replicate or spread

Question 16

How to protect against malware (2)

Answer 16

• Improved code quality

- Monitoring and protection

Question 17

Code quality

Answer 17

Malware often takes advantage of buffer overflows so avoid dat stuff

Question 18

Monitoring and protection

Answer 18

Regular scans for viruses