Pseudonymisation
The process of replacing directly identifying data with pseudonyms, so the data can no longer be attributed to a specific individual without additional information.
Full Definition
Pseudonymisation is a data protection technique in which directly identifying information is replaced with a pseudonym (a key or token) and the linking information is kept separately and securely. Unlike anonymisation, pseudonymisation is reversible — the data can be re-identified using the separately stored key. GDPR explicitly recognises pseudonymisation as a way to reduce privacy risks and incentivises its use, but pseudonymised data is still considered personal data and remains subject to GDPR. Common pseudonymisation approaches include tokenisation, encryption, and hashing. It is a key tool for privacy-preserving analytics.
Related terms
Anonymisation
The irreversible process of altering data so that individuals can no longer be identified, directly or indirectly.
Data Minimisation
The principle that only personal data that is adequate, relevant, and limited to what is necessary should be collected and processed.
Personal Data
Any information that relates to an identified or identifiable natural person.
Relevant regulations
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