Table 1 shows the CIA categories for computer security (as per lecture). Once you read through this you will then be asked to complete table 2 which contains some devices or software that are either specifically used for security or may be used in order to help secure computer systems.

Computer security has many aspects. In order to keep things relatively simple, we have briefly considered the main tenets of computer security CIA (Confidentiality, Integrity and Availability). This is also often called the CIA Triangle.

As is evident CIA stands for Confidentiality, Integrity, and Availability. These are the three tenets or cornerstones of information security objectives. Virtually all practices within the umbrella called Information Security are designed to provide these objectives. They are relatively simple to understand and common-sense notions, yet very often misunderstood, leading to systems that do not protect information as they should. To become a good computer scientist you should understand CIA very well in order to understand the reasoning behind later practices as well as helping you to consider security during your personal use of computer systems.

Table 1 CIA Categories.

Category	Description
Confidentiality	Prevention of unauthorised disclosure of information (keep it secret or private). Only those authorised should see it.
Integrity	Prevention of unauthorised modification of information (dont allow it to be changed). Only those authorised should be allowed to change it.
Availability	Prevention of unauthorised withholding of information or resources. Information or resources should be available to authorised users whom wish to use them in a timely fashion.

Task 1

1. Complete the entries in table 2 and add two of your own devices or software. Dont worry too much about the category; just try to see if you can identify which one the element looks like it may help with. The first entry has been completed for you

Table 2 Security Devices - How they work and their CIA category.

Security or Infrastructure Element	Description [What type of device is it and what does it do? If network device, which layer does it operate at?]	HW or SW	CIA Category
Firewall	A firewall is a dedicated security mechanism. It can be hardware, software or a combination of both. Its job is to filter traffic as it enters or leaves a network. Firewalls can be stateful or stateless, meaning that they can either inspect the actual content of packets in transit (stateful) in order to detect malicious messages, or simply monitor where packets are coming from and going to (stateless).	HW, SW & Combination	C & A The firewall is trying to prevent the network being compromised or flooded. If it is compromised, confidentiality may be affected. If the network suffers a DoS availability will be affected.
Access Control List
Routers
Encryption
Switch
Group Policy
Intrusion Detection System