C2PA Provenance Audit

Audit required C2PA provenance assertions.

Description

C2PA provenance records can be inventoried by named assertions.

C2PA provenance records can be inventoried by named assertions. Label coverage indicates which required assertions have been recorded.^[1]

Audit required C2PA provenance assertions.

When to use C2PA Provenance Audit

Use this tool to audit required C2PA provenance assertions.

Prepare the text, recorded observations, aligned figures or editorial criteria requested. Confirm what each label, count, timestamp or supplied flag represents before interpreting the result.

How to use C2PA Provenance Audit and understand its results

Prepare the text, recorded observations, aligned figures or editorial criteria requested. Confirm what each label, count, timestamp or supplied flag represents before interpreting the result.
Enter requiredAssertions, presentAssertions using the field table and calculation rules, then run the tool.
Read coveragePercent, matched, missing, unexpected. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
requiredAssertions	Required C2PA assertions	list of string	Required
presentAssertions	Present C2PA assertions	list of string	Required

Supply required and observed assertion labels. Enter a nonempty required list and an observed list, which may be empty. Trim and lowercase entries for comparison; blank entries are errors. Deduplicate by normalized key. Return matched/missing required labels, unexpected observed labels, and coverage. Required order is preserved; the last trimmed spelling wins for duplicate keys.

coverage%=100×matchedUnique/requiredUnique

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
coveragePercent	Coverage (%)	number; minimum: 0; maximum: 100
matched	Matched items	list of string
missing	Missing items	list of string
unexpected	Unexpected items	list of string

json

{
  "input": {
    "requiredAssertions": [
      "alpha",
      "beta",
      "gamma"
    ],
    "presentAssertions": [
      "beta",
      "alpha",
      "extra"
    ]
  },
  "output": {
    "coveragePercent": 66.66666666666666,
    "matched": [
      "alpha",
      "beta"
    ],
    "missing": [
      "gamma"
    ],
    "unexpected": [
      "extra"
    ]
  }
}

Limitations and assumptions

No manifest, cryptographic signature, trust chain, media binding or assertion truth is verified.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Video Provenance Check: Compare caller-supplied expected and observed records for video provenance check. For a complementary task, use Photo Metadata Coverage: Compare caller-supplied requirements and observations for photo metadata coverage.

References

C2PA Provenance Audit — tool.io

Similar or alternative tools

Video Provenance Check
Compare caller-supplied expected and observed records for video provenance check.
Photo Metadata Coverage
Compare caller-supplied requirements and observations for photo metadata coverage.