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arXiv · 1504.00065

Optimality of the Laplace Mechanism in Differential Privacy

Fragkiskos Koufogiannis·Shuo Han·George J. Pappas
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Abstract

In the highly interconnected realm of Internet of Things, exchange of sensitive information raises severe privacy concerns. The Laplace mechanism -- adding Laplace-distributed artificial noise to sensitive data -- is one of the widely used methods of providing privacy guarantees within the framework of differential privacy. In this work, we present Lipschitz privacy, a slightly tighter version of differential privacy. We prove that the Laplace mechanism is optimal in the sense that it minimizes the mean-squared error for identity queries which provide privacy with respect to the $\ell_{1}$-norm. In addition to the $\ell_{1}$-norm which respects individuals' participation, we focus on the use of the $\ell_{2}$-norm which provides privacy of high-dimensional data. A variation of the Laplace mechanism is proven to have the optimal mean-squared error from the identity query. Finally, the optimal mechanism for the scenario in which individuals submit their high-dimensional sensitive data is derived.

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Fragkiskos Koufogiannis, Shuo Han, George J. Pappas. 2015-03-31. Optimality of the Laplace Mechanism in Differential Privacy. https://arxiv.org/abs/1504.00065

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