Advanced Verify mode
Forensic verification report
The audit-grade extension of Verify
Run a structured 10-step forensic verification on a file, a certificate PDF, a SHA-256 hash, or an attestation id. The pipeline produces a deterministic, byte-identical Verification Report (PDF + JSON) suitable for legal, audit, and forensic use.
Provide the input to verify
Drop the original file and a current copy. ExistBefore extracts metadata from each side locally and shows a semantic, severity-classified diff. Both files stay on your device.
Verification result
Forensic checklist
Comparison result
How Verify Pro differs from Verify
The public Verify page is built for one job: tell the user, in seconds, whether a file or a certificate is recognised by the ExistBefore registry. Verify Pro is built for a different audience — legal, audit, and forensic professionals who need a structured, reproducible verification record.
- Same cryptography, more transparency. Verify Pro runs the exact same offline ECDSA verification and registry cross-checks as the basic Verify flow, but exposes every intermediate step (10 entries, codes
VR01–VR10) with a per-step status, evidence, and reason code. - Deterministic Verification Report. The report is byte-identical across runs, browsers, and time zones for the same input + the same registry response. The PDF and JSON include a self-hash so any later edit to the file is detectable.
- Frozen catalog. The 10-step catalog is versioned (
existbefore-verifyreport-v1) and pinned by an inline-stability test. Adding, renaming, or reordering a step requires a version bump — the report stays mappable years later. - Privacy invariant preserved. Files never leave the browser. Only the SHA-256 transits via the proxy to the public registry, exactly as in the basic Verify flow.
What this report guarantees — and what it does not
Forensic verification is a chain of statements made under specific conditions. Verify Pro is explicit about which statements it can make and which it cannot.
What an Authentic verdict establishes
- The cryptographic signature embedded in the certificate validates against the public key the certificate also embeds.
- The fingerprint of the embedded key matches the fingerprint declared inside the certificate (no key swap).
- The public ExistBefore registry recognises the hash and returns the same attestation id and signing-key fingerprint embedded in the certificate.
- No tamper indicator was raised by any step of the pipeline.
What no Verify Pro report ever claims
- It does not claim the input was authored, owned, or controlled by any specific person or organisation. Cryptographic integrity is not attribution.
- It does not claim the input is unique, original, or first-of-its-kind. SHA-256 collisions are infeasible, but two parties may legitimately attest the same content.
- It does not grant any intellectual-property right. ExistBefore is a proof-of-existence layer, not a registry of rights.
How the 10-step pipeline runs
- VR01 — Input parsed. The input is recognised and routed to the correct path (file, certificate PDF, hash, or attestation id).
- VR02 — Hash computed. For files, the SHA-256 is computed locally with WebCrypto. For pre-supplied hashes and attestation ids, this step is not applicable.
- VR03 — Hash matches embedded. For certificate PDF input, the lookup hash is the same value embedded in the certificate. Internal divergence would already be a tamper indicator.
- VR04 — Embedded fingerprint matches embedded key. The SHA-256 of the embedded SPKI must equal the fingerprint declared in the certificate, otherwise the embedded key has been swapped.
- VR05 — Embedded signature is valid. The embedded ECDSA signature is verified against the embedded public key over the canonical signed payload.
- VR06 — Registry recognises the hash. The proxy forwards the hash to the public ExistBefore registry; an unrecognised hash means no attestation exists.
- VR07 — Registry attestation id matches embedded id. The certificate must not have been re-pointed at a different attestation.
- VR08 — Registry signing-key fingerprint matches embedded fingerprint. The same key must have signed the certificate and registered the attestation.
- VR09 — Current registry level vs generation level. The attestation may have been upgraded (T0 → T1 → T2) since the certificate was issued; this step reports the current level.
- VR10 — Embedded forensic findings. The producer-side forensic-findings snapshot embedded in the certificate is rendered verbatim and never re-computed at verification time.