Proof of “what & when” for your digital files — fast, verifiable, and shareable.
What is WrittenInStone?
WrittenInStone is a lightweight way to prove that a specific digital file existed at a specific time
and hasn’t changed since. We generate a cryptographic fingerprint (hash), bind it to a timestamp,
and provide a public verification page you can share (optionally as a QR code).
How does it work (in 3 steps)?
- Stamp — Upload a file (or call the API). We compute its hash and create a proof record with a timestamp.
- Share — Get a verification link and optional QR code.
- Verify — Anyone can re-check any file copy against your proof record at any time.
Open the Verification Checker
What does the proof confirm (and what doesn’t it confirm)?
- Confirms: file integrity (match/mismatch vs. the recorded fingerprint), existence of that fingerprint at the timestamp, and your audit trail (if enabled).
- Does not confirm: legal authorship or copyright ownership, or a qualified electronic signature/notarization by itself.
Is this a legal signature or a notarial act?
No. It’s technical proof of integrity and time. In practice, it often settles questions like “which file is original?”
or “was it edited after delivery?”. For formal signatures or notarization, use the methods your jurisdiction requires —
and attach a WrittenInStone proof to show the signed file wasn’t altered.
When is a notary usually not needed?
- Demonstrating creation time and integrity for creative works, drafts, datasets, or lab notes.
- Internal approvals where policy accepts technical proofs and audit logs.
- Handovers (team ↔ vendor) where both sides accept a verification link.
Where does WrittenInStone help most?
- Creators & studios: lock deliverables and end “silent edit” debates.
- Journalists & investigators: preserve originals and prove no hidden edits.
- Finance & compliance: anchor exports/reports and speed up audits.
- R&D & labs: timestamp datasets, notebooks, and models for later validation.
- Legal handovers: attach integrity proof to signed docs; simplify evidence chains.
What does a verification page show?
- Match result (does this file’s hash match the proof record?).
- Proof record ID and timestamp.
- “Stamped by” label (account/org), depending on what you choose to display.
- Optional audit events and basic metadata (plan/config dependent).
How do you handle privacy?
By default we store hash-only (fingerprints), not your file. That’s enough to verify later without exposing contents.
If you enable a premium vault, encrypted originals can be stored for redundancy and audit workflows. Tip: keep sensitive details out of any public metadata.
What’s available today vs. coming soon?
Available today Hash-based proof records + timestamps • Public verification pages • QR codes • Basic audit logs • API access.
Coming soon Similarity / duplicate detection • Extended provenance manifests • C2PA / Content Credentials export.
Pricing & accounts
- Free: core proofs and public verification links (within limits).
- Paid: higher limits, automation features, stronger audit/export options, and optional vault storage (depending on plan).
API & automation
Yes. Use the API to stamp files during export/publishing or CI/CD. Best practice: include your job/run IDs as metadata
so you can align internal logs with proof records.
What if I lose the original file?
Without the original (or an identical copy), you can’t prove a new file matches the proof record.
Keep your own backups — or use vault storage if you need redundancy.
Can I prove authorship?
WrittenInStone proves time + integrity. Authorship typically relies on context (account identity, workflow history, witnesses)
and/or a separate signing step.
Troubleshooting
- Hash mismatch: verify the exact file output; re-export from the source system and re-check.
- “Link not found”: use the checker above or regenerate a share link from your dashboard.
- Can’t upload: check size/type limits and your network; for large/batch workflows, use the API.
Where can I verify a file right now?
Open the Verification Checker
