Network Security Exam Practice (OCR J277 Paper 1 Style)

This lesson brings together everything you have learned about network security in OCR J277 Section 1.4. We will review the key topics, practise exam-style questions, and develop effective techniques for answering security questions in the OCR GCSE Computer Science Paper 1 exam.

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Key Topics Checklist

Before the exam, make sure you can confidently explain each of the following:

Topic	Key Points to Remember
Malware types	Virus (needs host), worm (self-replicating), trojan (disguised), ransomware (encrypts files), spyware (monitors), adware (adverts)
Social engineering	Phishing (fake emails), pharming (DNS redirect), shouldering (observation), blagging (false identity)
SQL injection	Malicious SQL in input fields; prevent with input validation and parameterised queries
Penetration testing	Authorised testing; black/white/grey box; find vulnerabilities before attackers
Firewalls	Monitor and control traffic based on rules; cannot stop all threats
Proxy servers	Intermediary; hides IP, filters content, caches pages
Encryption	Symmetric (one key, fast), asymmetric (two keys, solves key distribution)
Authentication	Passwords, biometrics, 2FA; three factors: know, have, are
Network policies	AUP, password policy, backup policy, disaster recovery
Physical security	Locked rooms, CCTV, biometric access, cable locks

The map below organises J277 1.4 threats into one mental model that you can draw quickly in revision.

mindmap
  root((Network Threats))
    Malware
      Virus
      Worm
      Trojan
      Ransomware
      Spyware
    Social Engineering
      Phishing
      Pharming
      Blagging
      Shouldering
    Technical Attacks
      SQL Injection
      Brute Force
      DDoS
    Insider
      Weak Passwords
      Lost Devices

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How Security Questions Appear in OCR J277 Paper 1

Network security questions in OCR J277 Paper 1 typically appear as:

Short-answer questions (1-3 marks)

• "Define the term malware." (1 mark)
• "Give two examples of social engineering." (2 marks)
• "State one advantage of asymmetric over symmetric encryption." (1 mark)

Description questions (2-4 marks)

• "Describe how a phishing attack works." (3 marks)
• "Describe the purpose of penetration testing." (2 marks)
• "Explain how a firewall protects a network." (3 marks)

Extended-response questions (6-8 marks)

• "Discuss the security threats facing a company's network and recommend measures to protect against them." (8 marks)
• "A school wants to improve its network security. Evaluate the measures it could take." (6 marks)

OCR Exam Tip: For extended-response questions, structure your answer with clear paragraphs. Discuss multiple threats and multiple prevention methods. Use specific terminology (e.g. "two-factor authentication" not "extra security"). Link each threat to a specific prevention method.

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Worked Example: Short Answer

Question: State what is meant by the term 'social engineering' in the context of network security. (2 marks)

Model answer: Social engineering is the manipulation of people (1) into revealing confidential information or performing actions that compromise security (1).

Marking guidance:

• 1 mark for the idea of manipulating/deceiving people.
• 1 mark for the purpose (revealing information / gaining access / compromising security).

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Worked Example: Description

Question: Describe how SQL injection can be used to gain unauthorised access to a database. (3 marks)

Model answer: The attacker enters malicious SQL code into an input field on a website (1), such as a login form. If the input is not validated/sanitised, the SQL code is executed by the database server (1). This can allow the attacker to bypass authentication, read sensitive data, or modify/delete records (1).

Marking guidance:

• 1 mark for entering SQL code into an input field.
• 1 mark for lack of input validation allowing execution.
• 1 mark for the impact (bypass login / read data / modify data).

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Worked Example: Extended Response

Question: A small business stores customer data on a network. Discuss the threats to this data and recommend measures to protect against them. (8 marks)

Model answer structure:

Paragraph 1 — Malware threat: The business is vulnerable to malware such as ransomware, which could encrypt customer data and demand payment. To protect against this, the company should install and regularly update anti-malware software and ensure all operating systems and software are patched with the latest security updates.

Paragraph 2 — Phishing and social engineering: Employees could be targeted by phishing emails attempting to steal login credentials. Staff training should be provided so employees can recognise suspicious emails. Two-factor authentication should be implemented so that stolen passwords alone are not sufficient for access.

Paragraph 3 — Unauthorised access: Attackers may attempt brute force attacks or SQL injection to access the database. The business should use strong password policies, implement firewalls to control incoming traffic, and ensure all web applications use input validation and parameterised queries to prevent SQL injection.

Paragraph 4 — Physical and policy measures: Servers should be kept in locked rooms with restricted access. Regular backups should be stored off-site so data can be recovered if compromised. A disaster recovery plan should define how the business will respond to a security incident.

OCR Exam Tip: In extended response questions, aim for at least 3-4 well-developed paragraphs. Each paragraph should name a specific threat, explain how it works, and recommend a specific prevention method. Use technical terminology throughout.

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Common Exam Mistakes to Avoid

Mistake	Correction
Describing what malware does without naming specific types	Always name specific malware types (virus, worm, trojan, etc.)
Saying "use antivirus" as the only prevention method	Mention multiple layers: firewall, encryption, authentication, policies
Confusing phishing with pharming	Phishing uses fake emails; pharming redirects via DNS
Saying encryption "prevents hacking"	Encryption protects data confidentiality if intercepted — it does not prevent access to systems
Ignoring physical security	Always consider physical measures alongside technical ones
Writing vague answers	Use specific terminology and detailed explanations

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Quick Revision: Key Definitions