PHSafe: Disclosure Avoidance for the 2020 Census Supplemental Demographic and Housing Characteristics File (S-DHC)
This paper addresses privacy-preserving release of the 2020 U.S. Census Supplemental Demographic and Housing Characteristics (S-DHC) files. Method: It proposes the first zero-concentrated differential privacy (zCDP) framework designed for large-scale official statistics, introducing the discrete Gaussian mechanism for national-level statistical disclosure—rigorously proving its zCDP compliance—and implementing it via the Tumult Analytics platform to enable verifiable, production-grade privacy computation. Contribution/Results: (1) The first formally verified, production-deployed zCDP algorithm; (2) a demonstrable balance between strong privacy guarantees (zCDP) and high statistical utility on real-world census infrastructure; (3) a scalable, auditable privacy-enhancing paradigm for official statistics. The solution has been operationalized in the S-DHC data release system, marking a milestone in the U.S. Census Bureau’s privacy protection practice.