The Data Passport

The evidence document delivered with every run. It records what is in the data, what is not, and what nobody tested, and it keeps saying so when the answer is unflattering.

Eleven sections, always in this order

Pick a section to see what it holds. Facts shown are from the run of 27 Sep 2026.

§ 1 of 11RUN-745029d75136

Identity and intended use

Which generator, specification, seed and population size produced the data, and what it is meant to test.

- Generator: hde.compose.Composer/0.2-construct-fill-repair EVAL-0.1
- Run: RUN-745029d75136
- Specification: medication_safety v1
- Seed: 7
- Population: 3000 patients

Three sentences every Passport carries

Word for word, in every run. They show how we write about what the data does and does not establish.

This assessment measures coverage of a declared specification and the properties listed. It does not establish that the data is anonymous, that its use is lawful, or that any system tested against it is clinically safe.

This rule set is incomplete and covers only the named domain. A dataset can satisfy every rule applied here and still be clinically wrong in ways these rules do not check.

Not tested: attacks using auxiliary external datasets; attacks with access to generator parameters; disclosure through attributes not declared as quasi-identifiers; longitudinal structure beyond the tested columns; any risk arising after the data leaves the environment where it was assessed.

A real excerpt

Sections 1 and 9 from the 3,000-patient run of 27 Sep 2026, unedited.

We report what we did not measure, instead of returning a reassuring zero or a combined score.

“NaN here means NOT MEASURED, not zero risk and not a low value.” That line is in the Passport itself.

Data Passport excerpt, run of 27 Sep 2026
# Data Passport

## 1. Identity and intended use
- Generator: hde.compose.Composer/0.2-construct-fill-repair EVAL-0.1
- Run: RUN-745029d75136
- Specification: medication_safety v1
- Seed: 7
- Population: 3000 patients

## 9. Privacy measurements
- privacy.singling_out_rate = 0.0267 proportion of records unique on the stated quasi-identifiers
  - assumptions: those three fields are what an adversary would know in advance.
    That choice is a judgement and a different choice gives a different number
- privacy.exact_match_rate = NOT MEASURED
  - NaN here means NOT MEASURED, not zero risk and not a low value.

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