Cybersecurity principles and threats
Connect confidentiality, integrity, authenticity, availability and non-repudiation to the threats that can undermine them.
Section 4 · Data integrity and cybersecurity
Mapped to the Cambridge IGCSE Computer Science 0265 syllabus for exams in 2029. These original explanations and self-checks are independent study support, not Cambridge papers, official marks or grades. Practical programming is taught with worked code and trace tasks; an executable Python workspace and timed digital-exam simulation are not yet available.
Before you begin
- Use the 2029 syllabus for this course. Cambridge specifies Python 3.10 or higher for programming and digital exams for both components. The syllabus currently identifies this route for 2029 only; confirm later-year availability with Cambridge and your school.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
Before cybersecurity principles and threats, which statement is the safest starting point?
What you will learn
- State the five cybersecurity principles
- Describe the aims and processes of specified threats
- Connect threats to the principles they endanger
Security protects more than secrecy
Confidentiality limits information to authorised people; integrity protects data from improper change; authenticity helps establish that a person or message is genuine; availability keeps services usable; non-repudiation provides evidence that an action occurred and cannot easily be denied.
A threat can affect several principles. A DDoS attack targets availability, while data interception threatens confidentiality. Unauthorised changes threaten integrity; stolen credentials can undermine authenticity and confidentiality.
Recognise how attacks work
A brute-force attack tries many password combinations. A virus attaches to a file or program and spreads when it is run; a worm can replicate across networks without attaching to a host file; a Trojan disguises itself as legitimate software. Spyware secretly collects information, adware displays unwanted advertising, and ransomware blocks access or encrypts data to demand payment.
Phishing uses deceptive messages or sites; pharming redirects users to a fraudulent destination; social engineering manipulates people into unsafe actions. Data interception captures information in transit, and SQL injection uses crafted input to alter a database query. Hacking and unauthorised access exploit weaknesses to enter a system. Describe the mechanism and likely impact rather than only naming the threat.
Pause and explain
Which habit best checks your understanding of cybersecurity principles and threats?
Worked example
A website is flooded with requests until legitimate learners cannot access it. Identify the threat and principle affected.
Show the worked solution
- The service is overwhelmed by a large volume of traffic.
- A distributed denial-of-service attack uses many systems to flood a target.
- The main principle affected is availability.
Answer DDoS; availability
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
A message imitates a school's login portal and asks a learner to sign in urgently. Identify the threat and explain its purpose.
Give me a hint
Look for deception and the requested action.
Compare my reasoning
- The message impersonates a trusted organisation.
- It directs the learner to a login page to obtain credentials.
- This is phishing, a form of social engineering.
Phishing intended to steal login credentials.
Look for these in your work
- Threat identified
- Mechanism described
- Purpose stated
A database query is altered by input that changes the condition and returns records the user should not see. Name the attack and explain the weakness it exploits.
Give me a hint
Focus on untrusted input changing the meaning of a database query.
Compare my reasoning
- The input is treated as part of the query rather than only as data.
- The attacker changes the query condition to retrieve unauthorised records.
- This is SQL injection; input handling and query construction are weaknesses.
SQL injection exploits unsafe query construction so input changes a database command.
Look for these in your work
- Attack named
- Query effect stated
- Weakness explained
A ransomware attack encrypts files and demands payment. Identify two security principles at risk and justify each.
Give me a hint
Consider access to data and whether the stored data remains under authorised control.
Compare my reasoning
- Availability is at risk because users may be unable to access the files.
- Integrity or confidentiality may also be at risk if data is modified or exposed.
- State that the exact impact depends on what the malware did and whether backups exist.
Availability is directly threatened; integrity or confidentiality may also be affected depending on the attack.
Look for these in your work
- Principles named
- Impacts linked
- Scope qualified
Common mistakes
- Treating all malware as if it spreads in the same way.
- Saying phishing requires the attacker to break encryption.
- Explaining a threat without linking it to the affected principle.
What can you explain now?
Which principle is most directly affected when a service is unavailable?
Compare with the explanation
Availability
Availability concerns whether authorised users can access a system or data when needed.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
How do the five cybersecurity principles help you explain the impact of different attacks?
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.