MAC addresses linked to users

Identifies documents containing references to mac addresses linked to users in Australian contexts. This information type is classified as personally identifiable information under applicable data protection regulations.

Type

regex

Engine

boost_regex

Confidence

medium

Confidence justification

category-aware structural regex with anchor and context constraints replaces phrase-only detection. Added context gating and exclusion rules improve precision and reduce incidental matches.

Detection quality

Topic false positive

Jurisdictions

global

Regulations

SOCI Act 2018 (Cth), TIA Act 1979 (Cth), GDPR

Frameworks

CIS Controls, DISP, ISO 27001, NIST CSF, SOC 2

Data categories

pii

Scope

wide

Risk rating

7

Platform compatibility

Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Degraded, Netskope: Unsupported

Pattern

(?is)\b(?:MAC\s+addresses\s+linked\s+to\s+users|MAC\s+address|hardware\s+address|physical\s+address|network\s+interface|WiFi\s+address|Bluetooth\s+address|device\s+fingerprint|network\s+identifier|ethernet\s+address|wireless\s+adapter)\b

Corroborative evidence keywords

mac addresses linked to users, mac, addresses, linked, users, contact, location, data, address, age, birthday, citizenship, city, date of birth, [object Object], email, ethnicity, fax, first name, full name (+51 more)

Proximity: 300 characters

Should match

• MAC addresses linked to users — Primary topic phrase match
• mac address — Case-insensitive topic phrase match
• hardware address — Alternative topic phrase match
• physical address — Additional topic phrase match
• Access log: MAC address assigned to employee Priya Rao. — Device-address concept with explicit user-linkage relation (reaches the enforcing tiers)

Should not match

• unrelated generic text without domain phrases — No relevant topic phrases present
• placeholder value 12345 — Random text should not match topic-specific regex
• address mac — Generic word pair from old broad template should not match
• Router physical address configuration guide. — Hardware documentation without any user-linkage relation must not reach the enforcing tiers
• Security training shows how a MAC address can be linked to users. — Explanatory prose — linked to users is not an authored relational linkage phrase, so enforcement must not fire

Known false positives

• Common words and phrases related to mac addresses linked to users appearing in policy documents, training materials, HR templates, or compliance guidelines without actual personal data. Mitigation: Require corroborative evidence keywords within the proximity window to confirm sensitive data context rather than general discussion.
• In Australian English, similar terminology used in formal or administrative contexts (education, professional documentation) that does not constitute sensitive data collection. Mitigation: Layer with additional contextual signals such as structured identifiers, form fields, or database column headers to distinguish sensitive records from general references.
• High-frequency pattern matches in large document corpora due to broad regex anchors. Expected match rate is significantly higher than specific identifier patterns. Mitigation: Tune confidence thresholds for bulk scanning. Consider using this pattern primarily as a pre-filter with secondary validation.

References

• https://www.oaic.gov.au/privacy/your-privacy-rights/your-personal-information/what-is-personal-information
• https://www.oaic.gov.au/privacy/your-privacy-rights/your-personal-information/what-is-sensitive-information
• https://www.oaic.gov.au/privacy/australian-privacy-principles-guidelines
• https://www.service.nsw.gov.au/transaction/check-a-vehicle-registration
• https://www.gsma.com/get-involved/working-groups/terminal-steering-group/imei-database/
• https://www.itu.int/rec/T-REC-E.118.1/en