PHSafe: Disclosure Avoidance for the 2020 Census Supplemental Demographic and Housing Characteristics File (S-DHC)

This article describes the disclosure avoidance algorithm that the U.S. Census Bureau used to protect the 2020 Census Supplemental Demographic and Housing Characteristics File (S-DHC). The tabulations contain statistics of counts of U.S. persons living in certain types of households, including averages. The article describes the PHSafe algorithm, which is based on adding noise drawn from a discrete Gaussian distribution to the statistics of interest. We prove that the algorithm satisfies a well-studied variant of differential privacy, called zero-concentrated differential privacy. We then describe how the algorithm was implemented on Tumult Analytics and briefly outline the parameterization and tuning of the algorithm.

@article{sexton2025_2505.01254,
  title={ PHSafe: Disclosure Avoidance for the 2020 Census Supplemental Demographic and Housing Characteristics File (S-DHC) },
  author={ William Sexton and Skye Berghel and Bayard Carlson and Sam Haney and Luke Hartman and Michael Hay and Ashwin Machanavajjhala and Gerome Miklau and Amritha Pai and Simran Rajpal and David Pujol and Ruchit Shrestha and Daniel Simmons-Marengo },
  journal={arXiv preprint arXiv:2505.01254},
  year={ 2025 }
}