Methods of Protecting Networks (Edexcel GCSE Computer Science)

Access Control

What are access controls?

• Access controls ensure users of a network can access what they need to access and do not have access to information/resources they shouldn't

• Users can have designated roles on a network

• Some examples of different levels of access to a school network include

  • Administrators: Unrestricted - Can access all areas of the network

  • Teaching Staff: Partially restricted - Can access all student data but cannot access other staff members' data

  • Students: Restricted - Can only access their own data and files

• Users and groups of users can be given specific file permissions

What are file permissions?

• File permissions can be set to determine different levels of access to specific files/folders

• Examples of file permissions include:

  • Read - can read the contents of a file only

  • Write - can make changes to file contents and/or create new files

  • Delete - can delete files

  • Execute - can run applications/launch software

What is authentication?

• Authentication is the process of ensuring that a system is secure by asking the user to complete tasks to prove they are an authorised user of the system

• Authentication is done because bots can submit data in online forms

• Authentication can be done in several ways, these include

  • Usernames and passwords

  • Multi-factor authentication

  • CAPTCHA - see example below

Physical Security

What is physical security?

• Physical security is a method of physically preventing access to any part of a network

• There are a range of physical security measures that can be implemented on a network

  • Locked doors: Preventing access to server rooms and cabinets of switches

  • Biometrics: Fingerprint scanners, facial recognition and retinal scans 

  • Surveillance Cameras: Monitoring the activity around the site where crucial networking hardware is located

What form of attack would this prevent?

• Data interception and theft

• Social engineering

Firewalls

What is a firewall?

• A firewall monitors incoming and outgoing network traffic and uses a set of rules to determine which traffic to allow

• A firewall prevents unwanted traffic from entering a network by filtering requests to ensure they are legitimate

• It can be both hardware and software and they are often used together to provide stronger security to a network

  • Hardware firewalls will protect the whole network and prevent unauthorised traffic

  • Software firewalls will protect the individual devices on the network, monitoring the data going to and from each computer

What form of attack would this prevent?

• Hackers

• Malware

• Unauthorised Access to a Network