What is Network Security?

Network security is a level of guarantee that all the machines in a network are working optimally and the users of these machines only possess the rights that were granted to them.

This can include:

• preventing unauthorized people from acting on the system maliciously
• preventing users from performing involuntary operations that are capable of harming the system
• securing data by anticipating failures
• guaranteeing that services are not interrupted

The Causes of Insecurity

Insecurities are generally broken down into two categories:

• An active state of insecurity, i.e. user ignorance of the system's functionalities, some of which can be harmful to the system (e.g. not deactivating network services that are not needed by user)
• a passive state of insecurity, i.e. when the administrator (or user) of a system is not familiar with the security mechanisms that are in place

The Goals of Attackers

Attackers (also called "pirates" or "hackers") can have many motives:

• the appeal of the forbidden
• a desire for money (e.g. by violating a bank system)
• reputation (impress their friends)
• a desire to do harm (destroy data, keep a system from functioning)

Attacker Behaviour

The goal of attackers is often to take control of a machine in order to be able to perform desired actions. There are different ways in which to do this:

• by obtaining information that can be used in attacks
• by exploiting system weaknesses
• by using force to crack a system

How can you protect yourself?

• stay informed
• know your operating system
• reduce network access (firewall)
• reduce the number of entry points (ports)
• define an internal security policy (passwords, activation of executables)
• deploy security utilities (logging)