Interactive privacy via the median mechanism

13 years 4 months ago
Interactive privacy via the median mechanism
We define a new interactive differentially private mechanism — the median mechanism — for answering arbitrary predicate queries that arrive online. Given fixed accuracy and privacy constraints, this mechanism can answer exponentially more queries than the previously best known interactive privacy mechanism (the Laplace mechanism, which independently perturbs each query result). With respect to the number of queries, our guarantee is close to the best possible, even for non-interactive privacy mechanisms. Conceptually, the median mechanism is the first privacy mechanism capable of identifying and exploiting correlations among queries in an interactive setting. We also give an efficient implementation of the median mechanism, with running time polynomial in the number of queries, the database size, and the domain size. This efficient implementation guarantees privacy for all input databases, and accurate query results for almost all input distributions. The dependence of the pri...
Aaron Roth, Tim Roughgarden
Added 18 Jul 2010
Updated 18 Jul 2010
Type Conference
Year 2010
Where STOC
Authors Aaron Roth, Tim Roughgarden
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