System security

User Access Levels 

In a large company or school, many people will be using computers on the same network. A network manager will normally control the level of access people have to the network. General users will not have the ability to download software or they want or to make changes to any part of the system, as that could affect other users.

The more people have access to sensitive parts of the network, the more likely it is that a hacker or a virus might be able to cause damage.

You can set user access levels on your home computer. For example, a parent may prevent a child from being able to install software.

Encryption

Any message sent over a network can be intercepted. encryptionis a method of changing the original numbers and characters so that they are hidden or disguised. This is important if you are sending sensitive information.

One method of encryption is the Caesar Cipher algorthims. In this method, each letter of the alphabet is simply replaced by another letter in the alphabet that might be one or more letter positions away.

For example, encrypting using letters which are +5 positions away would change the original text ‘computing into cipher text ‘Gnyjxbedt".

The prefix for some web addresses is https instead of http. The ‘s’ indicates that it is a secure website and any payment or personal details that are inputted into the site will be encrypted.

Network policies

Network policies provide rules and guidelines on what network users can and cannot do. Most networks in large organisations will have network policies in place.

Acceptable Use Policy (AUP)

An AUP states how the network may be used – what is and is not acceptable. If you are going to let people use your network, then you should have an agreement in place which states the rules and guidelines for users.

Archiving

Networks often have to store a lot of data. A good archiving strategy takes old, non-essential data and puts it somewhere safe. An archiving policy will help decide when to move data, where it should be kept, and how to get it back if needed.

There are more details about how to make a network reliable in