Verdicts and the Risk Score
How signals combine into a score and a verdict.
How the score is computed
Every signal has a weight from 0 to 100 and a confidence from 0 to 1. The score combines them so several medium signals add up, while one weak signal cannot dominate:
Scoring
risk_score = 100 * (1 - product of (1 - weight * confidence / 100))A valid digital signature with no changes after signing subtracts a fixed amount.
Score bands
| Score | Verdict |
|---|---|
| 0 to 34 | No issues found |
| 35 to 69 | Needs review |
| 70 to 100 | Likely tampered |
Overrides
- A critical provenance signal, such as Content Credentials naming an image generator, sets the verdict to AI generated.
- Two confident high-severity signals from different layers set at least Likely tampered.
Tip. Every result records the engine and ruleset version that produced it, so old results stay explainable after rules change.