Propose-filter-release: privately drop the outliers, then your noise can scale to typical data instead of the worst case
AspireAI community · arXiv
Differentially private mechanisms usually scale their noise to the worst-case influence of a single record, which lets a handful of outliers dictate how much noise everyone pays. This paper introduces propose-filter-release, which privately filters its input first, converting a mechanism that only protects a typical record into one that is differentially private in the standard sense on every input. The construction needs only a concave friendliness score measuring how well a record fits the dataset, and a release mechanism that is friendly-DP, meaning private when the changed record fits the rest of the data, so it works as a general privacy primitive alongside propose-test-release, with FriendlyCore recoverable as one instantiation. The guarantee holds under public conditions on the number of records, which is the main limitation: the privacy statement is conditional rather than unbounded.
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