AI Governance Engineer
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Pseudonymisation

By Updated

Processing personal data so it can no longer be attributed to a person without additional information kept separately and protected 1. Pseudonymised data stays personal data for whoever can re-attribute it; it is a security measure, not anonymisation.

Developed in
ch. 19, Anonymisation versus pseudonymisation
Chapters
ch. 19, Privacy & AI
Contrast with
Anonymous data
Source
1 numbered reference, listed below

Commonly confused

  • Pseudonymisation versus Anonymous data

    Pseudonymisation
    Processing personal data so it can no longer be attributed to a person without additional information kept separately and protected.
    Anonymous data
    Information that does not relate to an identifiable person, judged against all the means reasonably likely to be used by anyone to identify them.

    The differenceRe-attributable with separately kept information, so still personal data, against not relating to an identifiable person at all.

    Why it mattersPseudonymised data keeps every GDPR duty; an anonymity claim needs a dated assessment.

Where it is used

6 chapters of the Body of Knowledge use the term. Each link opens the first section that does.

Sources

  1. [1] Regulation (EU) 2016/679 (General Data Protection Regulation) (Arts. 4(1), 4(5), 4(7), 4(8), 4(12), 4(14), 5, 6, 9, 12(3), 22, 25, 28(2) and 28(4), 30, 33, 35; Recital 26). Publications Office of the EU (EUR-Lex). 2016-04-27. https://eur-lex.europa.eu/eli/reg/2016/679/oj/eng (verified: primary)

Definitions of legal terms paraphrase the cited text, which governs. Dated statements are as of .

Cite this term

García Aibar, J. (2026). Pseudonymisation. In AI Governance Engineering: The Thesis & Body of Knowledge (v0.5.0), Glossary. https://doi.org/10.5281/zenodo.22956197. https://aigovernanceengineer.com/glossary/pseudonymisation. CC BY 4.0

BibTeX

@misc{aige2026pseudonymisation,
  author  = {Jorge García Aibar},
  title   = {{Pseudonymisation}},
  note    = {Glossary, AI Governance Engineering: The Thesis \& Body of Knowledge, version 0.5.0},
  year    = {2026},
  doi     = {10.5281/zenodo.22956197},
  url     = {https://aigovernanceengineer.com/glossary/pseudonymisation}
}