Week 8 - Security

Question 1

What are the 5 approaches to security

Answer 1

• No Security
• Security through obscurity (only recommend security for a known weakness in the organisation)
• Host Security
• Network Security
• Combination of Host & Network Security (most common)

Also…
Physical Security: access card
Logical Security: PIN number

Question 2

What security threats does an e-commerce site face?

Answer 2

• Defacing your website (obvious)
• Altering your website, e.g., change selling prices? (not always obvious)
• Stealing customer data

Question 3

What two factors need to be considered in security?

Answer 3

Cost & performance

Question 4

What are the 7 characteristics requiring protection?

Answer 4

1. Confidentiality
2. Integrity (can you trust data is not altered)
3. Availability (is it up & running)
4. Authentication (are you who you say you are)
5. Non-repudiation (evidence that transaction was performed)
6. Privacy (who else can see my details)
7. Access control (who has access to what?)

Question 5

What are the two things we are trying to protect?

Answer 5

Our Resources (anything flowing or sitting in org)
o Hardware
o Software
o Storage (Backup & Recovery)
o Bandwidth (Cables/Flow of Data)

Our Reputation
o Corruption of Web Pages
o Forged E-Mail
o Phishing

Question 6

What type of attacks are there?

Answer 6

1. Intrusion
2. Denial of Service (DOS or DDOS)
3. Information Theft
4. Stupidity

Question 7

Intrusion Detection Systems

Answer 7

When an unauthorised person enters the network.
Network based: monitors traffic on the cables
Host based: software implemented in each host & monitors individual computers.

Question 8

Denial of Service or DDOS

Answer 8

Objective: to make target systems unavailable to the real users.
o Send excessive pings to a server (flooding) which must be responded to. Server slows and crashes & the real users cannot access it.
Distributed DOS: having multiple people in different locations pinging the server.

Question 9

Information Theft

Answer 9

The attacker can passively record data communications to gather sensitive information that may be passing between two hosts.
Happneing unknowingly to users.

Question 10

Stupidity

Answer 10

Unknowingly giving access & information without realising its contents.

Question 11

What is the goal of security?

Answer 11

To build in layers of security/protection to make it difficult for a hacker to penetrate your network.

Question 12

Explain the role of a firewall

Answer 12

(1) Allow acceptable traffic to enter (2) Prevent any suspicious external data packets attempting to enter the internal network.
it is a software that needs to be updated & maintained.

Question 13

Why do firewalls need a security policy?

Answer 13

Firewall rules are dependent on the security policy.
Security Policy will inform the firewall what data to allow & deny. E.g., school servers do not allow YouTube to be accessed.

Question 14

Where must the firewall be situated?

Answer 14

Must be placed at the boundary between the internal & external network.
All traffic coming from the Internet and going out from the internal network passes through the firewall

Question 15

What is the most common firewall & what does it do?

Answer 15

screening router/packet filtering router…
The firewall only reads the header as that is where the information about whether to deny or allow the packet is contained.
- Determines if ‘destination address’ is within its network
- Screens the packet based on firewall rules

Question 16

What can’t a firewall do & what must you implement instead?

Answer 16

Prevent viruses or anything that does not go THROUGH the firewall.
Need an anti-virus software.

Question 17

A security plan: mgmt policies

Answer 17

• Risk assessment – security cost vs potential loss risk matrix
• Security audit: penetration testing (consultants hack network to find problems within the network)
• Security (tradeoff): (greater security = slower, vice versa)
• Vulnerability, threat, likelihood of attack, loss