δ-Presence without Complete World Knowledge

Advances in information technology, and its use in research, are increasing both the need for anonymized data and the risks of poor anonymization. In [CHECK END OF SENTENCE], we presented a new privacy metric, \delta-presence, that clearly links the quality of anonymization to the risk posed by inadequate anonymization. It was shown that existing anonymization techniques are inappropriate for situations where \delta--presence is a good metric (specifically, where knowing an individual is in the database poses a privacy risk). This article addresses a practical problem with [CHECK END OF SENTENCE], extending to situations where the data anonymizer is not assumed to have complete world knowledge. The algorithms are evaluated in the context of a real-world scenario, demonstrating practical applicability of the approach.