# Update Signing Verification Evidence

Status: Complete

## Goal

Prove signed update/manifest verification behavior for Phase IV release hardening.

## Evidence

1. Signed-manifest verification tests and output:
   - `docs/phase4/artifacts/update-signing-tests-2026-02-11.log`
2. Signature tamper rejection test (fails closed):
   - `model_manager::tests::invalid_manifest_signature_rejects_and_quarantines_partial`
   - result: `ok`
3. Artifact tamper rejection and quarantine test:
   - `model_manager::tests::tampered_model_is_rejected_and_quarantined`
   - result: `ok`
4. Runtime verification path:
   - `src-tauri/src/model_manager/mod.rs` (`validate_manifest_signature`, `install_model_resumable`)
   - signature check occurs before install flow continues.
   - tampered/invalid artifacts are rejected and quarantined.

## Notes

1. During Phase IV hardening, an orphan-partial edge case was fixed so invalid-signature paths quarantine partial artifacts even without checkpoint metadata.