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Small-cell re-identification risk
A cell with very few observed individuals (e.g. 1-3) can be cross-referenced with public or other data sources to re-identify a specific person, even without any single field being personally identifiable on its own.
Class
Case to account for
Affects
2 conversions
01
Detection
Per-cell unique-individual count below a defined re-identification risk threshold (commonly k=5 or higher depending on sensitivity).
02
Mitigation
01
Suppress or roll up any cell below the k-anonymity threshold to a coarser resolution
02
Apply the same suppression rule consistently across all output cuts (time, cell, segment) of the same underlying data
03
Affected conversions
PointH3
OPENRasterH3
OPENMore in Privacy
Consent-based precision reductionDeclared unit below the precise-location thresholdDevice trajectory exposureDifferential privacy noise calibrationHousehold-level targeting riskK-anonymity thresholdsMinimum aggregation windowRegional privacy restrictionsResolution degradation policySparse-audience suppressionTemporal leakage