BLENDER: Enabling Local Search with a Hybrid Differential Privacy Model

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Brendan Avent
Aleksandra Korolova
David Zeber
Torgeir Hovden
Benjamin Livshits


We propose a hybrid model of differential privacy that considers a combination of regular and opt-in users who desire the differential privacy guarantees of the local privacy model and the trusted curator model, respectively. We demonstrate that within this model, it is possible to design a new type of blended algorithm that improves the utility of obtained data, while providing users with their desired privacy guarantees.
We apply this algorithm to the task of privately computing the head of the search log and show that the blended approach provides significant improvements in the utility of the data compared to related work.
Specifically, on two large search click data sets, comprising 1.75 and 16 GB, respectively, our approach attains NDCG values exceeding 95% across a range of privacy budget values.

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How to Cite
Avent, Brendan, Aleksandra Korolova, David Zeber, Torgeir Hovden, and Benjamin Livshits. 2019. “BLENDER: Enabling Local Search With a Hybrid Differential Privacy Model”. Journal of Privacy and Confidentiality 9 (2).
TPDP 2017

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