Network security — Edexcel GCSE Computer Science
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Network security explained
Network security matters because a network carries valuable data and shared services, so a single weakness can expose many users at once.
Read the full explanation
Learners should be able to explain why protection is important, for example a school network holding pupil records, and then match each threat to a suitable defence. Vulnerabilities are identified by penetration testing, where an authorised tester probes a system with the owner's permission to find weaknesses before criminals do, and by ethical hacking, which uses the same techniques under a legal agreement. Protection methods include access control, such as usernames, strong passwords and permission levels that limit what each user can open; physical security, such as locked server rooms, CCTV and key-card entry, which stops direct tampering or theft; and firewalls, which filter incoming and outgoing traffic against rules.
Your focus
- State why network security is important for data, hardware and shared services.
- Describe how penetration testing and ethical hacking identify vulnerabilities.
- Identify access control, physical security and firewalls as methods of protecting a network.
Network security exam tips
Marking Points
- Network security protects data, hardware and services shared across a network, so one weakness can affect many users.
- Penetration testing is authorised probing of a system to find vulnerabilities before attackers exploit them.
- Ethical hacking uses the same techniques as malicious hacking but with permission and within legal and contractual limits.
- Access control restricts who may use a system or which resources they may open, using logins, passwords and permission levels.
- Physical security protects equipment directly, for example locked rooms, CCTV and key-card entry to server areas.
- A firewall filters network traffic against a set of rules to block unwanted or suspicious connections.
Examiner Tips
- 💡Underline the key noun in the question, such as firewall, access control or penetration testing, before reading the options.
- 💡Eliminate options that describe a different category of protection from the one named in the question.
- 💡Check whether the question asks why security matters or how a method works, because the correct option must match that purpose.
Common Mistakes
- Thinking ethical hacking is the same as criminal hacking: the correction is that ethical hacking is authorised, agreed in advance and bounded by law and contract.
- Believing a firewall stops all malware: the correction is that a firewall filters traffic by rules and cannot remove malware already installed or opened by a user.
- Confusing access control with physical security: the correction is that access control governs logical use of accounts and resources, while physical security protects the equipment itself.