14: Privacy and Firewalls

Question 1

What are sources of online privacy risks ?

Answer 1

• HTTP cookies which store history data
• Any kind of log files
• Search engine trackers
• Social network trackers
• ISP, government, employers surveillance

Question 2

Give 8 principles of the Data Protection Act (1998) ?

Answer 2

• Accurate
• Secure
• Fairly and lawfully processed
• Processed for limited purposes
• Adequate, relevant and not excessive
• Not kept longer than necessary
• Data subject’s right are respected
• Not transferred to countries without adequate protection.

Question 3

What is the gist of the Data Protection Act ?

Answer 3

People have a right to see their data and can insist on removing irrelevant data if they want.

Furthermore, companies need your PERMISSION if they want to use the data they collected on your for some purpose other than the original intention.

They cannot sell your data without ASKING.

Question 4

What is the security practice like in Britain ?

Answer 4

• Mass government surveillance.

- ISPs keep copies of everything.

Question 5

How to increase security ?

Answer 5

• Disable cookies
• Use ad-blockers, VPN, anonymous emails
• OpenPGP

Question 6

How does a proxy or VPN work ?

Answer 6

It prevents one’s IP address from being forwarded to the website in use.

Question 7

What is a firewall ?

Answer 7

A network security system which monitors and controls the incoming and outgoing network traffic based on predetermined rules.

Question 8

Give 4 types of firewall controls ?

Answer 8

• Service control: which types of internet services are available
• Direction control: flow through firewall
• User control: local users
• Behaviour control: eliminates spam

Question 9

What does the first generation: packet filters do ?

Answer 9

It looks at the network addresses and ports of a packet and determines if the filter

allows, drops or rejects

the packet.

Question 10

What does the second generation: stateful filters do ?

Answer 10

Circuit level gateaways.

• Operate up to transport layer of OSI model
• Retain packets until enough information to make judgement about its state

Filter determines whether a packet is the:

• Start of a new connection
• Part of an existing connection
• Not part of any connection

Question 11

Is the connection state a filter criteria ?

Answer 11

Yes

Question 12

What does the third generation: application layer ?

Answer 12

Firewall ‘understands’ applications and protocols such as

HTTP, DNS, FTP,

and it can detect if an unwanted application is trying to bypass the firewall using an allowed port.