A-Level Computer Science / Unit 6: Protecting Data and Ensuring Accuracy

6.1.1 Security, Privacy and Data Integrity

🔒 Lesson slides are available to signed-in users. Sign in

6.1.1 Security, Privacy and Data Integrity

Computer systems often hold data that people and organisations depend on. To discuss how that data should be protected, we need three related ideas: security, privacy and integrity. They overlap, but each one focuses on a different question.

By the end of this section, you should be able to:

  • Distinguish between data security, data privacy and data integrity.
  • Use each term accurately when analysing a computing scenario.
  • Explain why protecting the data is not enough unless the computer system is also protected.
  • Explain how a security failure can damage privacy, integrity or availability.

Three Different Questions

A useful way to separate the terms is to ask three different questions about the same dataset.

Concept Main question What a failure might look like
Data integrity Can the data be trusted as accurate and current? A record contains an incorrect quantity or an obsolete address.
Data privacy Is the data only seen and used by authorised people? A confidential file is displayed to someone without permission.
Data security Is the data protected against loss, damage, alteration and unauthorised access? Files are deleted, corrupted, stolen or unavailable when required.
Common misconception: These terms are not interchangeable. A dataset can satisfy one requirement while failing another.

Data Integrity

Data has integrity when it remains accurate and up to date for the task in which it is being used. Integrity can be damaged by typing mistakes, incorrect processing, unauthorised changes, failed transfers or records that have not been updated.

Data integrity: the requirement for data to be accurate and kept current.

Example: equipment records

A climbing centre's database reports that 26 safety helmets are available. A recent inspection removed four damaged helmets, but the database was not updated. The record is stored securely and only staff can view it, yet its integrity is poor because the value is no longer current.

Exam tip: A strong definition should include both accurate and up to date. Writing only “the data is correct” may not show the full idea.

Data Privacy

Privacy concerns who is permitted to access data and how that data is used. An authorised user is someone who has been given permission to perform a particular action, such as viewing or editing a record. Different users may need different levels of access.

Data privacy: the requirement that data is only accessible and used by authorised people.

Example: staff records

A company receptionist may need access to staff names and office extensions. This does not mean the receptionist should also be able to open payroll records. Both files belong to the same organisation, but their privacy requirements are different.

Common misconception: Private data does not have to be hidden from everyone. It may be available to several authorised users while still remaining private.

Data Security

Data security is the broader protection applied to data. It aims to prevent unauthorised access or alteration, reduce the chance of loss or corruption, and make sure authorised users can obtain the data when it is needed.

Data security: protecting data from unauthorised access, alteration, loss and damage, while keeping it available to authorised users.

Consider a theatre booking system. If customer bookings are encrypted but the only copy of the database is destroyed by a storage failure, confidentiality may have been preserved, but security has still failed because the data is no longer available or recoverable.

Exam tip: When explaining security, describe a consequence. Useful consequences include unauthorised disclosure, unwanted modification, permanent loss or inability to access the data.

Why Both the Data and the System Need Protection

Data is stored, processed and transmitted by a computer system. Protecting a file is therefore not enough if the device, operating system, user accounts or network around it can be compromised. System security protects the environment that handles the data; data security protects the data itself.

Area being protected What must be maintained Example of failure Possible effect on data
Computer system Authorised use and continued operation An attacker gains control of an administrator account. Files may be viewed, changed or deleted.
Stored data Protection from disclosure, alteration, corruption and loss A database file is overwritten by an incorrect version. Records may become inaccurate or unavailable.
Networked service Reliable access for legitimate users The service stops responding during a critical period. Correct data exists but cannot be used when required.
Availability: authorised users can access the system and data when they need them.

Later sections examine the threats that can cause these failures and the security measures used to reduce the risks.

How the Concepts Connect

Security supports privacy and integrity, but it does not automatically guarantee either one. A well-protected system can still contain inaccurate data, and an authorised user can still misuse information or make an incorrect change.

Scenario Integrity Privacy Security
A members-only timetable is correct, current and restricted to registered users. Maintained Maintained Maintained
A delivery address is visible only to authorised staff, but it is three years out of date. Failed Maintained Partly maintained
A correct employee rota is accidentally published on a public webpage. Maintained Failed Failed
A correct encrypted database cannot be restored after the storage device fails. May be maintained May be maintained Failed
Common misconception: “Secure” does not simply mean “secret”. Security also includes protecting data from unwanted changes and making it available to legitimate users.

Interactive: Integrity, Privacy or Security?

Read each situation and choose the concept that is most directly affected. Some incidents influence more than one concept, so use the feedback to compare the strongest answer with the wider effects.

Scenario

Outdated booking total

A venue database still shows 40 available seats even though 12 more tickets have just been sold.

Make a choice

Choose the term that best describes the main problem in the scenario.

Security Protects the system and data
Integrity Keeps data accurate and current
Privacy Controls access and use

Common Mistakes and Misconceptions

  • Using security, privacy and integrity as synonyms.
  • Describing integrity as “only authorised users can see the data”. That describes privacy.
  • Assuming private data must be inaccessible to everyone rather than restricted to authorised users.
  • Forgetting availability when explaining security.
  • Assuming strong security controls will correct data that was already inaccurate.
  • Discussing only the data file and ignoring the system that stores and processes it.

Practice

Knowledge and application

  1. Write separate definitions for data integrity, data privacy and data security.
  2. Explain why an accurate dataset might still fail to meet privacy requirements.
  3. Explain why restricting access to a database does not guarantee that its records have integrity.
  4. A wildlife centre stores animal feeding records on a secure server. One record lists the wrong food quantity because a keeper selected the wrong value. Identify the main concept affected and justify your answer.
  5. A travel company keeps customer passport details in a file that all employees can open. The details are accurate and backed up. Explain which requirement has failed and why.
  6. A repair workshop's database is correct and access-controlled, but a server fault makes it unavailable for two days. Explain why this is still a security failure.
  7. Explain why protecting the computer system is necessary for protecting the data stored on it.
  8. Create your own scenario in which privacy is maintained but integrity is not.
Answer structure: name the concept, state its meaning, and connect it to a detail in the scenario. For example: “This is an integrity problem because the stored value is inaccurate.”

Review

Prompt Essential idea
What does integrity focus on? Whether data is accurate and up to date.
What does privacy focus on? Whether access and use are limited to authorised people.
What does security focus on? Protection against unauthorised access, alteration, loss and damage, together with availability.
Why protect the computer system? A compromised or unavailable system can expose, change, destroy or block access to its data.
Does security guarantee integrity? No. Securely stored data may still be incorrect or out of date.
Final exam tip: Pay attention to the noun in the question. If it asks about privacy, focus on authorised access and use; if it asks about integrity, focus on accuracy and currency; if it asks about security, discuss protection and availability.