Matching the PUMF against a population registry. This figure shows the process that would be used in by an attacker. The ID field is only included here to make it easier to see which records are included in each data set. In reality there would be no consistent ID field available across the data sets.
Emam et al. BMC Medical Informatics and Decision Making 2011 11:53 doi:10.1186/1472-6947-11-53