This repository contains source code for the SafeTab-H disclosure avoidance application. SafeTab-H was used by the Census Bureau for the protection of individual 2020 Census responses in the tabulation and publication of the Detailed Demographic and Housing Characteristics File B (DDHC-B). Previously, the Census Bureau has released the source code for SafeTab-P, the application used to protect the Detailed Demographic and Housing Characteristics File A (DDHC-A).

Using the mathematical principles of formal privacy, SafeTab-H infused noise into Census survey results to create privacy-protected microdata which were used by Bureau subject matter experts to tabulate the 2020 DDHC-H product. SafeTab-H was built on Tumult's "Analytics" and "Core" platforms. both SafeTab-H and the underlying platforms are implemented in Python. The latest version of the platforms can be found at [[https://tmlt.dev/]].

In the interests of both transparency and scientific advancement, the Census Bureau committed to releasing any source code used in creation of products protected by formal privacy guarantees. In the case of the the Detailed Demographic & Housing Characteristics publications, this includes code developed under contract by Tumult Software (tmlt.io) and MITRE corporation. Tumult's underlying platform is evolving and the code in the repository is a snapshot of the code used for the production of the DDHC-B product.

The bureau has already separately released the internally developed software for the Top Down Algorithm (TDA) used in production of the 2020 Redistricting and the 2020 Demographic & Housing Characteristics products.

This software int this repository is divided across multiple sub-directories, including:

• configs contains the specific configuration files used for the production DDHC-B runs, including privacy loss budget (PLB) allocations and the rules for adaptive table generation. These configurations reflect decisions by the Bureau's DSEP (Data Stewardship Executive Policy) committee based on experiments conducted by Census Bureau staff.
• safetab-h/safetab_h contains the source code for the application itself as used to generate the protected microdata used in production.
• safetab-h/safetab_utils contains utilities common among the SafeTab products developed by Tumult for the Census Bureau.
• mitre/cef_readers contains code by MITRE to read the Census input files used by the SafeTab applications.
• tumult contains the Tumult Analytics platform. This is divided into common, analytics, and core directories. The core directory also includes a pre-packaged Python wheel for the core library.
• ctools contains Python utility libraries developed the the Census Bureau's DAS team and used by the MITRE CEF readers.