Article
CIA triad: Confidentiality, integrity, and availability
What is the CIA triad?
The CIA triad is an information security model that is based on three pillars—confidentiality, integrity, and availability. This model provides organizations with a guide for establishing security procedures and policies that address these three critical areas. Despite being broad and high-level, the CIA triad is a proven model for directing planning efforts as well as identifying cybersecurity threats and implementing security and risk mitigation solutions to stop or minimize them.
The three elements of the CIA triad, while important aspects of an effective security posture, are sometimes in conflict.
For instance, data access solutions for confidentiality can be cumbersome and interfere with data availability. The right balance between the CIA triad components is dictated by organizations’ unique requirements.
Not all cybersecurity threats are from cyber attacks launched from outside of the enterprise. Because of this, CIA triad controls for confidentiality need to take into account external cyber criminals as well as accidental and malicious insiders.
Examples of security controls used across the CIA triad include:
- Confidentiality policies
- Data classification
- Data governance programs
- Data retention policies
- Digital access control methods, such as multi-factor authentication and passwordless sign-on
- Encryption for data at rest and data in motion
- Enterprise security systems
- Non-disclosure agreements
- Physical access controls
- Strong passwords
- Anti-virus software
- Endpoint protections
- Data loss prevention solutions
- Endpoint detection and response (EDR)
- Firewalls
- Identity and access management (IAM)
- Intrusion detection and protection systems (IDS/IPS)
- Role-based access control (RBAC) systems
Confidentiality
Confidentiality refers to protecting information from unauthorized access by implementing systems and processes to enforce restrictions on information access, use, and sharing. To uphold the highest standards for data protection and ensure the security of sensitive information, the CIA triad confidentiality implementation should have access limited to least privilege. This means users are only granted access to information that they explicitly need for only as long as it is needed.
Requiring multi-factor authentication when a user accesses an account is an example of confidentiality. In this case, a user logs into a website and is prompted to input a code that has been sent to their mobile device. This can be followed up by answering a security question.
Integrity
Integrity means that data is protected from unauthorized modification or deletion. This component of the CIA triad ensures that data is trustworthy and complete.
Hashing, encryption, digital certificates, and digital signatures are examples of the integrity component of the CIA triad. These methods verify integrity and ensure that authenticity cannot be repudiated or denied.
Availability
Availability means that users have timely and reliable access to data when they need it. This means that systems must be protected from tampering.
The availability of element of the CIA triad is often the proverbial canary in the coal mine; if systems have been compromised, availability is usually one of the first indicators of trouble.
Because of this, it is commonly given priority over the other two elements of the CIA triad—confidentiality and integrity.
Examples of availability disruptions that the CIA triad seeks to avoid and mitigate are DDoS (distributed denial of service) attacks and ransomware. These, along with other availability-related attack vectors, are the focus of security efforts related to availability. Even if data is kept confidential and its integrity maintained, it is of no value to anyone if it is inaccessible.
Why enterprises use the CIA triad
The simple yet powerful CIA triad is widely used by enterprises of all types. Among the many reasons why are that the CIA triad:
- Assists in coordinating incident response plans
- Can be used as a framework for security training programs
- Facilitates assessments of what went right and wrong in the wake of a cybersecurity incident
- Helps disrupt cyber kill chains
- Identifies gaps and high-performing areas to help replicate effective policies and solutions
- Protects critical and sensitive assets from unauthorized access
- Provides a simple yet comprehensive high-level checklist for selecting, implementing, and maintaining security procedures and tools
CIA triad FAQ
What does CIA stand for in the CIA triad?
Contrary to widely held assumptions, CIA in the CIA triad does not stand for Central Intelligence Agency. It stands for confidentiality, integrity, and availability.
How does the CIA triad protect organizations from cybersecurity threats?
The CIA triad elements provide protection against cybersecurity threats by leveraging the best practices, solutions, and models used for enterprise security and those that are included in IT general controls.
What is the importance of the CIA triad in cybersecurity?
The CIA triad provides an overarching guide to information security. It helps organizations assess their environments, identify gaps, find solutions, and optimize existing implementations. By considering all three pillars of the CIA triad, organizations are forced to consider and weigh the importance of each area to find the right balance and take a holistic approach to security.
What standards reference the CIA triad?
As a lynchpin of the information security ecosystem, the CIA triad is referenced in a number of standards, including the ISO 27001 global standard for managing information security and the European Union’s General Data Protection Regulation (GDPR), one of the toughest privacy and security laws in the world, which mentions the CIA triad in Article 32 (i.e., “ensure the ongoing confidentiality, integrity, availability, and resilience of processing systems and services.”
What Center for Internet Security, Inc. (CIS®) controls apply to the CIA triad?
Formerly the SANS Critical Security Controls or the SANS Top 20, the CIS Critical Security Controls (CIS Controls) include three that cover the CIA triad.
- Confidentiality
CIS Control 6–Access Control Management
Use processes and tools to create, assign, manage, and revoke access credentials and privileges for user, administrator, and service accounts for enterprise assets and software. - Integrity
CIS Control 3–Data Protection
Develop processes and technical controls to identify, classify, securely handle, retain, and dispose of data. - Availability
CIS Control 11–Data Recovery
Establish and maintain data recovery practices sufficient to restore in-scope enterprise assets to a pre-incident and trusted state.
What are CIA triad tradeoffs?
With the CIA triad, prioritizing one or more elements usually results in a tradeoff of others. For example, an organization that needs extremely high availability for a set of data could see a reduction in confidentiality as access controls are loosened.
What is the history of the CIA triad?
While the concept of the CIA triad cannot be claimed to be the creation of a single individual or organization, it is widely connected to the U.S. military and government. In 1976, confidentiality appeared in a U.S. Air Force study. Subsequently, the concept of integrity was introduced in a 1987 dissertation titled A Comparison of Commercial and Military Computer Security Policies, which was written by David Clark and David Wilson. The first reference to the CIA triad was in 1989 by the Joint Service Committee on Military Justice (JSC).
The CIA triad: Fundamentals that are simple, but not easy
At its most basic level, the core of information security is built around the CIA triad. This tried-and-true guideline can support the enterprise in developing and maintaining the security posture needed to protect its assets.
The efficacy of the CIA triad is reinforced by its representation in most of the world’s information security guides, best practices, and standards. The CIA triad is even included in security and privacy regulations.
Do not be fooled by the ostensible simplicity of the CIA triad. It should be included in every security practitioner’s toolbox.
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