Data Masking for Sensitive Information
Use data masking to hide sensitive info based on policy requirements and legal obligations.
Plain language
Data masking is a technique to hide sensitive information, like personal details, from those who shouldn’t see it. It’s important because if sensitive data like credit card numbers or private health details are exposed, they can lead to financial fraud or privacy breaches.
Framework
ISO/IEC 27001:2022
Control effect
Preventative
ISO 27001 domain
Technological controls
Classifications
N/A
Official last update
24 Oct 2022
Control Stack last updated
12 Apr 2026
Maturity levels
N/A
Official control statement
Data masking shall be used in accordance with the organization’s topic-specific policy on access control and other related topic-specific policies, and business requirements, taking applicable legislation into consideration.
Why it matters
Without data masking, PII and other sensitive data may be exposed in logs, reports, and test environments, causing privacy breaches and legal non-compliance.
Operational notes
Review masking rules per dataset and use case (test, analytics, logging); validate formats remain usable while identifiers are obscured, and update for new fields and laws.
Implementation tips
- The IT manager should implement data masking by identifying which types of data are considered sensitive, such as personal identification numbers or financial information. This involves collaborating with data owners to understand what data needs protection and using software tools that hide this data during processing or storage, in line with ISO 27002:2022 guidance.
- The Policy Team should work with the IT department to develop and update data masking policies. This includes defining criteria for when and how data masking is to be employed, considering requirements like the Privacy Act 1988 and other relevant regulations.
- Data Protection Officers should regularly review and assess the data masking techniques being used to ensure they are effective. They can achieve this by keeping up-to-date with best practices and consulting the latest standards, such as ISO 27002:2022.
- HR should train employees on the importance of data masking and how to handle sensitive data securely. This training should be part of the induction process and regularly refreshed, combining real-world examples with compliance obligations like those under the Australian Privacy Principles.
- The Governance Board should oversee the compliance of data masking practices with legal and organisational standards. They should regularly receive reports showing data usage and incidents to ensure that the implementation of data masking aligns with the declared policies and the organisation's risk management framework.
Audit / evidence tips
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Askthe data masking policy document
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Askexamples of masked data outputs
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Askdata protection incident reports that include details on data handling breaches
Goodsystem would show fewer incidents and rapid response and resolution procedures
Cross-framework mappings
How Annex A 8.11 relates to controls across ISO/IEC 27001, Essential Eight, and ASD ISM.
ASD ISM
| Control | Notes | Details |
|---|---|---|
| sync_alt Partially overlaps (1) expand_less | ||
| ISM-1268 | Annex A 8.11 requires organisations to apply data masking for sensitive information in line with access control policy, business needs, a... | |
These mappings show relationships between controls across frameworks. They do not imply full equivalence or certification.