Category: Privacy and Security

Security Control

Also known as: Safeguard, Countermeasure

Simply put

A security control is a safeguard or countermeasure put in place to protect information, systems, or physical property from security threats. Controls may work by avoiding, detecting, counteracting, or reducing the impact of a security risk. Examples range from technical measures to physical and administrative practices.

Formal definition

A security control is a safeguard or countermeasure prescribed for an information system or an organization to protect the confidentiality, integrity, and availability of the system and its information. Controls are commonly classified by function, including preventive, detective, and corrective types; for example, a corrective control operates after an event has been detected and may reverse or limit its impact. In practice, controls are selected to avoid, detect, counteract, or minimize security risks and are typically drawn from established control catalogs and baselines. This entry addresses the concept of security controls generally and does not cover specific implementation, tooling, or the selection of a particular control framework.

Why it matters

Security controls are the practical mechanisms through which an organization translates its risk decisions into protection for information, systems, and physical property. Without controls, risk assessment remains theoretical; controls are the means by which identified risks are avoided, detected, counteracted, or reduced in impact. In governance and risk terms, they represent the treatment applied to threats against the confidentiality, integrity, and availability of information and systems.

The way controls are classified matters for how an organization designs its overall defenses. Preventive controls aim to stop an event before it occurs, detective controls identify that an event is taking place or has taken place, and corrective controls operate after an event has been detected and may reverse or limit its impact. Relying on any single type tends to leave gaps, so organizations commonly combine control functions so that a failure or bypass of one is caught or remediated by another.

Controls also provide the evidentiary basis for demonstrating that risk is being managed. Established catalogs and baselines, such as those maintained by NIST and the CIS Controls published by the Center for Internet Security, give organizations a structured starting point for selecting and describing safeguards. It should be noted that a control's presence does not by itself guarantee a risk is fully addressed; its effectiveness depends on correct selection, implementation, and operation, none of which this entry evaluates.

Who it's relevant to

Risk Managers

Risk managers rely on security controls as the treatment applied to identified risks. Understanding how preventive, detective, and corrective controls differ helps them assess whether the controls selected are proportionate to the risks they are meant to address and where residual exposure may remain.

Compliance Officers

Compliance officers use documented controls to demonstrate adherence to applicable security requirements and internal policies. Control catalogs and baselines provide a reference against which the presence and description of safeguards can be evidenced, though effectiveness must be assessed separately.

Internal Auditors

Internal auditors examine whether controls are designed appropriately and operating as intended. The distinction between a control and the risk it addresses is central to their work, and their assurance role remains independent of the management activity of implementing and operating those controls.

Information Security and IT Professionals

Security and IT practitioners select, configure, and operate controls across technical, physical, and administrative domains. They commonly draw from established frameworks such as the CIS Controls to achieve foundational security hygiene, combining control functions so that gaps in one are addressed by others.

Inside Security Control

Control Objective

The intended outcome a security control is designed to achieve, such as protecting the confidentiality, integrity, or availability of information assets. The control itself is the mechanism; the objective is the risk-reducing purpose it serves. These are distinct concepts and should not be conflated.

Control Type by Function

Security controls are commonly categorized by function, including preventive (aiming to stop an event before it occurs), detective (aiming to identify an event that has occurred), and corrective (aiming to restore or remediate after an event). A single control may serve more than one function.

Control Nature

Controls are often grouped as administrative (policies, procedures, and organizational measures), technical or logical (implemented through technology such as access controls or encryption), and physical (measures protecting facilities and hardware). The appropriate mix typically depends on the risks being addressed.

Control Design and Operating Effectiveness

Design effectiveness concerns whether a control, if operating as intended, would address its objective; operating effectiveness concerns whether it actually functions as designed over a period. Assurance functions commonly assess both, and a well-designed control may still fail operationally.

Relationship to Risk

Security controls treat risk, and their effect is often described in terms of the difference between inherent risk (before controls) and residual risk (the risk remaining after controls are applied). Controls typically reduce, but do not eliminate, risk.

Framework Context

Security controls are frequently defined or catalogued within recognized frameworks and standards. NIST publications maintained by the U.S. National Institute of Standards and Technology, and the ISO/IEC 27000 series of information security management standards issued jointly by ISO and IEC, are commonly referenced sources; the specific catalog and terminology vary by framework and jurisdiction.

Common questions

Answers to the questions practitioners most commonly ask about Security Control.

Is a security control the same as a control objective?

No. A control objective states the outcome an organization seeks to achieve, such as protecting the confidentiality of certain data, whereas a security control is a specific safeguard or measure implemented to help achieve that objective. A single control objective is typically supported by multiple controls, and one control may contribute to more than one objective. Conflating the two obscures whether a stated objective is actually being met by the controls in place.

Does implementing a security control guarantee that the associated risk is eliminated?

No. A security control is intended to reduce the likelihood or impact of a risk, not to eliminate it. Controls can fail, be circumvented, or be improperly configured, and residual risk commonly remains after a control operates. Presenting a control as a guarantee of a secure outcome overstates its effect; controls are more accurately understood as measures that modify risk to a level that may fall within an organization's risk tolerance.

How do preventive, detective, and corrective security controls differ in practice?

These categories describe when and how a control acts relative to an event. Preventive controls aim to stop an undesirable event from occurring, detective controls aim to identify that an event has occurred or is occurring, and corrective controls aim to restore a state or limit damage after an event. Many organizations combine all three so that a gap in one category may be partially addressed by another; the categories are functional descriptions rather than mutually exclusive types.

Who is responsible for operating a security control versus assessing it?

In many organizations aligned to a three lines model, operational management typically owns and operates security controls as part of day-to-day activity, while a risk or compliance function may set expectations and monitor them, and internal audit may provide independent assurance over their design and effectiveness. Keeping the operation of a control separate from its independent assessment supports the objectivity of assurance activities; the same party should generally not both operate and independently assure the same control.

How is the effectiveness of a security control commonly evaluated?

Evaluation commonly distinguishes design effectiveness, meaning whether the control as designed would address the intended risk, from operating effectiveness, meaning whether it functioned as intended over a period. Assessment techniques may include inspection of evidence, observation, reperformance, and inquiry. The appropriate approach depends on the control's nature and the level of assurance sought; this entry does not cover specific testing methodologies or tooling.

How should security controls be documented so they remain useful over time?

Documentation commonly records the control's objective, owner, description of how it operates, frequency, and the evidence it produces, so that operation and later assessment are repeatable. Linking each control to the risks or requirements it addresses helps demonstrate coverage and identify redundancy or gaps. Because organizational context and obligations change, control documentation is typically reviewed periodically; specific formats and retention practices vary by jurisdiction, sector, and organization.

Common misconceptions

A security control is the same as its control objective.

The objective is the outcome sought, such as safeguarding confidentiality, while the control is the specific measure implemented to pursue that outcome. Multiple controls may support one objective, and one control may support several objectives.

Implementing a security control guarantees the associated risk is eliminated.

Controls typically reduce risk rather than remove it. Residual risk commonly remains after controls are applied, and controls can fail in design or operation. Effectiveness should be assessed rather than assumed.

Reviewing or auditing a security control is part of operating that control.

Independent assurance over a control is distinct from the management activity of designing and operating it. Blurring the two undermines the independence and objectivity that assurance functions are expected to maintain.

Best practices

Define the control objective explicitly before selecting or designing a control, so the measure can be evaluated against the risk it is intended to treat.

Assess both design effectiveness and operating effectiveness, recognizing that a well-designed control may still fail in operation over time.

Use a balanced mix of administrative, technical, and physical controls appropriate to the risks being addressed rather than relying on a single control type.

Distinguish inherent from residual risk when evaluating controls, and document the residual risk that remains after controls are applied.

Align control selection and terminology with a recognized framework or standard, such as relevant NIST publications or the ISO/IEC 27000 series, while confirming the applicable scope for your jurisdiction and sector.

Preserve the independence of any assurance review of controls by separating those who design and operate controls from those who evaluate them.