anonymisoitu

Anonymisoitu is a Finnish term meaning “anonymized.” It describes information that has been processed to prevent the identification of the individuals it concerns. An anonymized data set has had identifying features removed or obscured, or has been sufficiently aggregated to prevent recognition of individuals.

Etymology: The word comes from anonymisoida, to anonymize, with the -tu ending forming a past participle. In Finnish technical usage, anonymisoitu data is contrasted with non-anonymized data and with pseudonymized data.

Usage: In data protection, research, and information security, anonymisoitu data is used to share or analyze information while reducing privacy risks. True anonymization implies that individuals are no longer identifiable by any reasonable means, even when combined with other data. It is distinct from pseudonymisoitu data, where direct identifiers are replaced with substitutes but re-identification remains possible with additional information.

Techniques: Common methods include removing direct identifiers (names, personal numbers), suppressing or aggregating variables (age bands, geographic levels), and applying masking or generalization. More advanced approaches involve statistical techniques such as k-anonymity, l-diversity, and differential privacy to balance privacy protection with data utility.

Legal context: Under the European Union framework, data that is truly anonymized is generally not subject to GDPR. The assessment is context-specific, and data that can be re-identified is not considered anonymized. Practitioners seek to demonstrate that re-identification risk is negligible.

Limitations: Anonymization is not risk-free; de-anonymization can occur through data linkage or external datasets. Ongoing risk assessment and appropriate technical safeguards are essential.