Resolution degradation policy

Privacy

When a cell fails a privacy check, the correct response is to roll it up to a coarser resolution and re-check, not to drop it or leave it at the original resolution with a suppressed value, either of which loses coverage or gives a false sense of the original grain.

Detection

Any cell in the output failing the k-anonymity/DP check should trigger a resolution rollup; audit for cells that were dropped or suppressed-in-place instead.

Mitigation

Implement automatic iterative rollup to h3ToParent until the privacy threshold is met
Document, per output row, the resolution actually reported versus the resolution originally requested

Affected conversions

PointH3
RasterH3
Admin polygonsH3 (weighted crosswalk)