Data representation and security · GCSE Computer Science

Privacy and cyber security

GCSE Computer Science privacy and security: threats, encryption, authentication, and the human layer beyond firewalls.

UNDERSTAND→RETRIEVE→REMEMBER
THE MEMORY HOOK
Most breaches start with a person or a weak password — then malware walks through the open door.

The important bits

What you need to know

  1. 1

    Privacy: control over personal information; surveillance vs security debate.

  2. 2

    Threats: malware, phishing, social engineering, DDoS, SQL injection, weak passwords, insider threat.

  3. 3

    Prevention: firewalls, anti-malware, encryption (data at rest and in transit), 2FA, hashing passwords with salt, least privilege, patching.

  4. 4

    Encryption: ciphertext unreadable without key; HTTPS (TLS) for web; end-to-end messaging.

  5. 5

    Authentication factors: something you know (password), have (token), are (biometric).

  6. 6

    Penetration testing and security policies — proactive vs reactive.

  7. 7

    Human factor: training, phishing simulations, physical security.

  8. 8

    Links to networks topic: HTTPS, VPNs, secure protocols.

Quotations worth analysing

Short evidence. Real method.

“Two-factor authentication demands a second factor the thief probably lacks.”
Security control summary

Pair with hashed password storage — defence in depth, not one silver bullet.

Go deeper

Match defence to threat

Encryption does not stop DDoS. Firewalls do not fix SQL injection in sloppy code. Markers notice scattergun lists.

WORKED EXAMPLE

See the idea in action

Scenario: stolen password database. Explain hashing with salt, 2FA, forced reset, phishing training. Identify threat (credential theft) and layered controls.

Exam technique

Turn knowledge into marks

Define phishing as social engineering with a technical payload.

Common mistakes

Do not give these marks away

  1. 01

    Firewall “removes viruses”.

  2. 02

    Encryption as complete security.

  3. 03

    Ignoring human layer.

QUICK RETRIEVAL

Which best reduces damage of a stolen password?

ATwo-factor authentication and hashed password storage

BHigher screen resolution

CBus topology

DLarger RAM

Show the answer

Two-factor authentication and hashed password storage. 2FA adds a second barrier; hashing means stolen DB is not plaintext passwords.

Quick questions

If this is the bit you searched

What is phishing?

Tricking users into revealing credentials or installing malware, often via fake emails or sites.