Private Mean Estimation of Heavy-Tailed Distributions

Gautam Kamath, Vikrant Singhal, Jonathan Ullman
Proceedings of Thirty Third Conference on Learning Theory, PMLR 125:2204-2235, 2020.

Abstract

We give new upper and lower bounds on the minimax sample complexity of differentially private mean estimation of distributions with bounded k-th moments. Roughly speaking, in the univariate case, we show that n=Θ(1α2+1αkk1ε) samples are necessary and sufficient to estimate the mean to α-accuracy under ε-differential privacy, or any of its common relaxations. This result demonstrates a qualitatively different behavior compared to estimation absent privacy constraints, for which the sample complexity is identical for all k2. We also give algorithms for the multivariate setting whose sample complexity is a factor of O(d) larger than the univariate case.

Cite this Paper


BibTeX
@InProceedings{pmlr-v125-kamath20a, title = {Private Mean Estimation of Heavy-Tailed Distributions}, author = {Kamath, Gautam and Singhal, Vikrant and Ullman, Jonathan}, booktitle = {Proceedings of Thirty Third Conference on Learning Theory}, pages = {2204--2235}, year = {2020}, editor = {Abernethy, Jacob and Agarwal, Shivani}, volume = {125}, series = {Proceedings of Machine Learning Research}, month = {09--12 Jul}, publisher = {PMLR}, pdf = {http://proceedings.mlr.press/v125/kamath20a/kamath20a.pdf}, url = {https://proceedings.mlr.press/v125/kamath20a.html}, abstract = { We give new upper and lower bounds on the minimax sample complexity of differentially private mean estimation of distributions with bounded $k$-th moments. Roughly speaking, in the univariate case, we show that $$n = \Theta\left(\frac{1}{\alpha^2} + \frac{1}{\alpha^{\frac{k}{k-1}}\varepsilon}\right)$$ samples are necessary and sufficient to estimate the mean to $\alpha$-accuracy under $\varepsilon$-differential privacy, or any of its common relaxations. This result demonstrates a qualitatively different behavior compared to estimation absent privacy constraints, for which the sample complexity is identical for all $k \geq 2$. We also give algorithms for the multivariate setting whose sample complexity is a factor of $O(d)$ larger than the univariate case.} }
Endnote
%0 Conference Paper %T Private Mean Estimation of Heavy-Tailed Distributions %A Gautam Kamath %A Vikrant Singhal %A Jonathan Ullman %B Proceedings of Thirty Third Conference on Learning Theory %C Proceedings of Machine Learning Research %D 2020 %E Jacob Abernethy %E Shivani Agarwal %F pmlr-v125-kamath20a %I PMLR %P 2204--2235 %U https://proceedings.mlr.press/v125/kamath20a.html %V 125 %X We give new upper and lower bounds on the minimax sample complexity of differentially private mean estimation of distributions with bounded $k$-th moments. Roughly speaking, in the univariate case, we show that $$n = \Theta\left(\frac{1}{\alpha^2} + \frac{1}{\alpha^{\frac{k}{k-1}}\varepsilon}\right)$$ samples are necessary and sufficient to estimate the mean to $\alpha$-accuracy under $\varepsilon$-differential privacy, or any of its common relaxations. This result demonstrates a qualitatively different behavior compared to estimation absent privacy constraints, for which the sample complexity is identical for all $k \geq 2$. We also give algorithms for the multivariate setting whose sample complexity is a factor of $O(d)$ larger than the univariate case.
APA
Kamath, G., Singhal, V. & Ullman, J.. (2020). Private Mean Estimation of Heavy-Tailed Distributions. Proceedings of Thirty Third Conference on Learning Theory, in Proceedings of Machine Learning Research 125:2204-2235 Available from https://proceedings.mlr.press/v125/kamath20a.html.

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