Deanonymisation Attack
A deanonymisation attack re-identifies people in data that was meant to be anonymous, by combining it with other information.
What is Deanonymisation Attack?
Forms include linkage attacks (matching anonymised records with other datasets), inference attacks (deducing hidden attributes from relationships), and structural attacks on network data such as social graphs. A "jigsaw" attack pieces together several innocuous items to identify someone. UK ICO guidance uses the "motivated intruder" test: whether a reasonably competent person, without specialist skills, could re-identify individuals.