Glossary
K-Anonymity
K-anonymity requires that every record in a released dataset be indistinguishable, on the fields that could identify someone, from at least a specified number of other records in the same dataset — meaning a value like age or zip code is generalized or suppressed until every combination of those fields covers a big enough group. Anyone examining the data can narrow a person down to that group, but not to a single individual within it.
This is a specific, measurable standard rather than a vague assurance of anonymity — but it has known limits: if most of a group happens to share the same sensitive value on some other field, k-anonymity alone doesn't stop that value from being inferred for everyone in the group, even without pinning down which specific individual it belongs to.