The CIA triad – confidentiality, integrity and availability – remains the foundational model for information security in 2025.

It’s embedded into virtually every modern security framework, from ISO 27001 to the GDPR. Article 32 of the GDPR explicitly refers to these principles when defining the necessary security measures for protecting personal data.

Understanding and applying the CIA triad correctly helps organisations manage risk, implement robust security controls and build operational resilience.

What Is the CIA triad?

The CIA triad refers to three core principles:

  • Confidentiality: Ensuring that sensitive data is accessed only by authorised parties.

  • Integrity: Protecting data from unauthorised modification to ensure accuracy and trustworthiness.

  • Availability: Making sure data and systems are accessible when needed by authorised users.

Watch our explainer video: What is the CIA triad and why is it important?

CIA step by step

Confidentiality

Confidentiality involves protecting personal and sensitive information from unauthorised access. This is commonly achieved through:

  • Encryption

  • Access controls and role-based permissions

  • Secure authentication (e.g. MFA/2FA)

Sensitive data might include customer records, employee information or intellectual property. Data should be siloed when possible, with critical assets (e.g. passwords, credit card numbers) stored separately from general user data.

Integrity

Integrity ensures that data is reliable, consistent and protected from unauthorised changes. This principle is especially important in:

  • Healthcare (e.g. ensuring patient records are accurate)

  • Financial services (e.g. preventing invoice tampering)

  • E-commerce (e.g. displaying the correct pricing to customers)

Controls like checksums, version control and audit trails help maintain integrity throughout the data lifecycle.

Availability

Availability ensures that authorised users can access information and systems as needed. Downtime can occur from:

  • Power outages

  • Hardware/software failures

  • Ransomware attacks or DDoS attacks

High availability is achieved by duplicating critical systems, keeping regular backups, using automatic failover and monitoring performance to catch issues early.

How the CIA triad works in practice

Security controls rarely support only one of the CIA triad principles. Often, strengthening one may impact another. For example:

  • Enabling MFA protects confidentiality, but may hinder availability if users lose access to their authentication method.

  • Encrypting data protects confidentiality and sometimes integrity, but if the keys are lost or corrupted, availability is at risk.

The triad encourages balance. Decisions must weigh risk and business impact — a core part of frameworks like ISO 27001 and the GDPR.

How the CIA triad supports compliance

Both ISO 27001 and the GDPR are rooted in risk-based thinking. Article 32 of the GDPR, for instance, mandates ‘a level of security appropriate to the risk’, referencing confidentiality, integrity, and availability explicitly.

Risk assessments are the entry point for aligning with the CIA triad. They allow organisations to:

  • Identify and prioritise risks

  • Assign controls based on likelihood and impact

  • Measure the effectiveness of those controls over time

Learn more about cyber security risk management

To gain a more in-depth understanding of how to manage risks to the confidentiality, integrity and availability of your information, take our Managing Cyber Security Risk Training Course.

It will help you:

  • Understand the geopolitical, legal and regulatory context of cyber risk;

  • Identify and assess threats and potential vulnerabilities and determine business impacts by conducting a risk assessment;

  • Appreciate how cyber governance structures help organisations protect their critical assets and meet regulatory compliance objectives;

  • Understand existing cyber security frameworks and standards to determine appropriate technical, procedural and personnel controls; and

  • Identify and respond to cyber security incidents.

See the course details

Frequently asked questions (FAQs)

What is the CIA Triad?

The CIA Triad is a core model in information security. It stands for Confidentiality, Integrity and Availability, the three principles that guide how organisations protect and manage data.

What does the CIA Triad stand for?

CIA stands for:

  • Confidentiality – ensuring only authorised people can access information.
  • Integrity – ensuring data is accurate, complete and trustworthy.
  • Availability – ensuring information and systems are accessible when needed.

What is confidentiality in the CIA Triad?

Confidentiality means protecting data from unauthorised access or disclosure. Common measures include encryption, access controls and data classification.

What is integrity in the CIA Triad?

Integrity ensures information remains accurate, consistent and unaltered except by authorised users. Hashing, checksums and version control help maintain integrity.

What is availability in the CIA Triad?

Availability means data and systems must be accessible to authorised users when required. This is supported by redundancy, disaster recovery and uptime monitoring.

Why is the CIA Triad important?

The CIA Triad is important because it provides a simple but effective framework for building and assessing security strategies. It ensures that organisations balance protecting data, maintaining trust and keeping systems usable.

What are the three principles of the CIA Triad?

The three principles are confidentiality, integrity, and availability. Together, they represent the goals every security control should achieve.

A version of this blog was first published in February 2023.