EVE ProofEvidence
EVE ProofEvidence
Signature verification proves a record was not altered. Replay verification proves something stronger: that the recorded verdict is exactly what the engine would decide again. Feed the certificate's deterministic inputs back into the same policy version, and the same verdict and reason code reproduce — every time.
They answer different questions an examiner asks. EVE Proof gives you both.
| Question | Answered by | How |
|---|---|---|
| "Was this record altered?" | Signature verification | Ed25519 over the canonical payload — any change breaks it. |
| "Is this the verdict the engine would give?" | Replay verification | Re-evaluate the inputs against the same policy version; the verdict reproduces. |
| "Did the inputs match the record?" | Digest check | The retained inputs hash to the certificate's request_digest. |
import hashlib, json, requests # 1. the inputs you retained hash to the digest in the certificate canon = json.dumps(saved_inputs, sort_keys=True, separators=(",", ":")).encode() assert "sha256:" + hashlib.sha256(canon).hexdigest() == cert["request_digest"] # 2. re-evaluate under the SAME policy version r = requests.post("https://eveaicore.com/v1/decisions/evaluate", headers={"Authorization": "Bearer eve_…"}, json={**saved_inputs, "policy_set": cert["policy_set"]}).json() # 3. the verdict reproduces, deterministically assert r["decision"]["status"] == cert["decision"] print("✓ same inputs, same policy → same verdict")
A probabilistic guardrail returns a likelihood that drifts between runs and model updates — it cannot be reproduced for an examiner. Deterministic governance can. Because the policy is decoupled from the model and versioned independently, the verdict in the certificate is not a snapshot of a moment; it is a function you can re-evaluate.
This is what lets a model-risk team confirm what a control did, when, and under which policy version — without relying on the first line's attestations. Read the governance argument on EVE Governance.
Verify a live decision certificate in your browser — then hand the evidence to your own auditor and watch them verify it without us.