Fundamentals of cyber security — AQA GCSE Computer Science

Fundamentals of cyber security covers the spectrum of threats that compromise computer systems and the layered countermeasures used to defend them. In the AQA GCSE specification, this encompasses cyber threats like malware, social engineering techniques, and structural network vulnerabilities, alongside technical and organisational mitigation strategies.

Understanding cyber security links closely to computer networks, data representation, and ethical or legal impacts. Mastering this topic allows students to analyse real-world vulnerability scenarios, evaluate system protection measures, and secure full marks across both short-answer definitions and extended-response exam questions.

• →Social engineering vectors: Phishing, shouldering (shoulder surfing), and blagging (pretexting) exploit human psychology rather than software vulnerabilities.
• →Malware classifications: Viruses, worms, trojans, ransomware, spyware, and adware differ in how they replicate, spread, and execute payloads.
• →Network-level attacks: Denial of Service (DoS/DDoS), brute force attacks, and SQL injection exploit protocol limits and unvalidated input fields.
• →Defence in depth: A robust security posture combines technical tools (firewalls, anti-malware, encryption, MAC filtering) and procedural policies (acceptable use policies, regular user training, strong authentication).

• Identifies that cyber security consists of processes, practices and technologies.
• Recognises that these are designed to protect networks, computers, programs and data.
• States that protection is against attack, damage or unauthorised access.
• Distinguishes processes and practices from technologies rather than treating cyber security as a single tool.
• Applies the definition to a scenario by identifying which asset and which threat an option addresses.

• 💡Underline the three elements, four assets and three threats in the question before choosing an option.
• 💡Reject any option that names a single tool as the whole of cyber security.
• 💡For scenario questions, ask which asset is being protected and which threat is being guarded against.
• 💡Use precise technical vocabulary: state 'packet inspection', 'brute force attack', 'salted hash', and 'social engineering' instead of conversational equivalents like 'checking data', 'guessing passwords', or 'tricking users'.
• 💡When answering 4-mark or 6-mark questions on system vulnerabilities, explicitly state the cause, the mechanism of exploit, and the specific mitigation technique.

• Selecting an option that lists only technologies such as firewalls and ignoring processes and practices; the correction is to require all three elements.
• Assuming cyber security protects only data and forgetting networks, computers and programs; the correction is to check every listed asset.
• Treating 'damage' as only deliberate harm when it also covers accidental harm; the correction is to keep all three threats in view.
• Believing anti-malware software stops incoming hackers: Anti-malware detects, quarantines, and removes malicious executable files; network firewalls control traffic and block unauthorized remote access.
• Assuming a worm requires human interaction: A virus requires an executable host file and human trigger to propagate, whereas a worm is standalone and self-replicates across networks automatically.
• Confusing penetration testing with passive vulnerability scanning: Penetration testing involves actively exploiting discovered vulnerabilities to evaluate damage potential, rather than simply listing known security patches.

1. 1Day 1-2: Review and create comparison tables for social engineering types (phishing, pharming, blagging, shouldering).
2. 2Day 3-4: Categorise malicious software (viruses, worms, trojans, ransomware, spyware) focusing on self-replication vs host reliance.
3. 3Day 5-6: Master technical prevention measures (firewalls, encryption, MAC address filtering, anti-malware, automated updates).
4. 4Day 7: Practise AQA past-paper questions focusing on 4-mark scenarios, penetration testing, and SQL injection.

• 📋Definition and differentiation questions (1-2 marks): E.g. 'State what is meant by a trojan' or 'State two differences between a virus and a worm'.
• 📋Scenario-based mitigation questions (4 marks): Explaining two distinct prevention methods to protect a named company from data theft.
• 📋Evaluation / Extended-response questions (6-9 marks): Evaluating the technical vs human factors in securing an enterprise network.