Principled Approaches for Private Adaptation from a Public Source
Raef Bassily, Mehryar Mohri, Ananda Theertha Suresh
Abstract
A key problem in a variety of applications is that of domain adaptation from a public source domain, for which a relatively large amount of labeled data with no privacy constraints is at one’s disposal, to a private target domain, for which a private sample is available with very few or no labeled data. In regression problems, where there are no privacy constraints on the source or target data, a discrepancy minimization approach was shown to outperform a number of other adaptation algorithm baselines. Building on that approach, we initiate a principled study of differentially private adaptation from a source domain with public labeled data to a target domain with unlabeled private data. We design differentially private discrepancy-based adaptation algorithms for this problem. The design and analysis of our private algorithms critically hinge upon several key properties we prove for a smooth approximation of the weighted discrepancy, such as its smoothness with respect to the $\ell_1$-norm and the sensitivity of its gradient. We formally show that our adaptation algorithms benefit from strong generalization and privacy guarantees.
BibTeX
@InProceedings{pmlr-v206-bassily23a,
title = {Principled Approaches for Private Adaptation from a Public Source},
author = {Bassily, Raef and Mohri, Mehryar and Suresh, Ananda Theertha},
booktitle = {Proceedings of The 26th International Conference on Artificial Intelligence and Statistics},
pages = {8405--8432},
year = {2023},
editor = {Ruiz, Francisco and Dy, Jennifer and van de Meent, Jan-Willem},
volume = {206},
series = {Proceedings of Machine Learning Research},
month = {25--27 Apr},
publisher = {PMLR},
pdf = {https://proceedings.mlr.press/v206/bassily23a/bassily23a.pdf},
url = {https://proceedings.mlr.press/v206/bassily23a.html},
abstract = {A key problem in a variety of applications is that of domain adaptation from a public source domain, for which a relatively large amount of labeled data with no privacy constraints is at one’s disposal, to a private target domain, for which a private sample is available with very few or no labeled data. In regression problems, where there are no privacy constraints on the source or target data, a discrepancy minimization approach was shown to outperform a number of other adaptation algorithm baselines. Building on that approach, we initiate a principled study of differentially private adaptation from a source domain with public labeled data to a target domain with unlabeled private data. We design differentially private discrepancy-based adaptation algorithms for this problem. The design and analysis of our private algorithms critically hinge upon several key properties we prove for a smooth approximation of the weighted discrepancy, such as its smoothness with respect to the $\ell_1$-norm and the sensitivity of its gradient. We formally show that our adaptation algorithms benefit from strong generalization and privacy guarantees.}
}