# Anonymization

URL: https://sellmydatatoai.net/glossary/anonymization

Anonymization is a process that removes the association between a dataset and the people it describes, so that no one can be identified from it.

Anonymization is a process that removes the association between an identifying dataset and the data subject, in the definition [NIST](https://csrc.nist.gov/glossary/term/anonymization) takes from ISO/TS 25237. US statutes rarely use the word. HIPAA and the CCPA set [de-identification](https://sellmydatatoai.net/glossary/de-identification) standards instead.

## When does the FTC treat data as anonymous?

The FTC treats data as anonymous only when it can never be associated back to a person. FTC staff said so in a [July 2024 post](https://www.ftc.gov/policy/advocacy-research/tech-at-ftc/2024/07/no-hashing-still-doesnt-make-your-data-anonymous) warning that hashed identifiers are not anonymous and that companies should not claim hashing makes personal information anonymized. A persistent ID that tracks a person or device over time does not meet the test.

## Is an AI model trained on personal data anonymous?

An AI model trained on personal data is not automatically anonymous. In the EU, the EDPB's [Opinion 28/2024](https://www.edpb.europa.eu/our-work-tools/our-documents/opinion-board-art-64/opinion-282024-certain-data-protection-aspects_en), adopted in December 2024, says such a model is anonymous only if the likelihood of extracting personal data from it, or obtaining it through queries, is insignificant.

## If you hold UK data

Under UK GDPR, anonymous information falls outside the law when identifying anyone from it is not reasonably likely, the test set out in the [ICO's anonymization guidance](https://ico.org.uk/for-organisations/uk-gdpr-guidance-and-resources/data-sharing/anonymisation/how-do-we-ensure-anonymisation-is-effective/).

Read our guide to [UK GDPR, EU GDPR and CCPA when selling data for AI training](https://sellmydatatoai.net/guides/gdpr-and-selling-data-for-ai-training) and [de-identification for AI training data](https://sellmydatatoai.net/guides/de-identification-for-ai-training-data).