Prove the existence and integrity of any document at a precise moment in time. Cryptographic hashes anchored on Polygon and Bitcoin. Admissible under eIDAS 2.0, Art. 2712 of the Italian Civil Code, and US FRE 901(b)(9).
Drop a file here — or browse
Your file never leaves this browser
Your file never leaves your browser. We compute SHA-256 client-side and transmit only the 64-character fingerprint.
Hashes are aggregated into a merkle tree. Each user gets a cryptographic proof binding their hash to the batch root.
The merkle root is written to a smart contract on Polygon (primary) and submitted to Bitcoin via OpenTimestamps (secondary).
Anyone can verify independently: recompute the hash, supply the proof, query timestamps(root) on-chain. No intermediary.
Blockchain timestamps are recognized as atypical proof in most legal systems. The burden of contestation falls on the opposing party.
| Jurisdiction | Reference | Evidentiary status |
|---|---|---|
| European Union | eIDAS 2.0 Art. 41 | Non-qualified electronic timestamp — admissible as free proof |
| Italy | Art. 2712 Codice Civile | Atypical proof — burden of contestation on opposing party |
| United States | FRE 901(b)(9) | Admissible upon demonstration of the technical process |
| Switzerland | ZPO — Free evaluation of evidence | Admissible with demonstration of method |
| United Kingdom | Electronic Communications Act 2000 | Admissible as electronic evidence |
| Singapore | Evidence Act, s. 36 | Admissible upon demonstrating reliability |
BA | Stamp is not a qualified trust service provider under eIDAS. We provide non-qualified electronic timestamps, which are explicitly recognized and admissible across the jurisdictions above.
File contents never leave the client. Only the SHA-256 hash is transmitted. Suitable for confidential material.
Polygon for fast finality and cost, Bitcoin via OpenTimestamps for long-term gravitas. Two independent attestations.
Public /verify pages let any third party confirm the anchor directly against the smart contract, with no account required.
Every stamp generates a jurisdiction-aware certificate with citations, merkle proof, and tx hashes.
Integrate stamping directly into your document flow. Available on Professional and Enterprise plans.
Drop a stamp-on-submit button into any form. White-label option for regulated firms.
Pay per stamp or subscribe for volume discounts.
Volume discounts available above 500 stamps / month. Fund Origin Analysis reports (in-depth investigations) quoted separately — $2,500–$8,000.
Built specifically for legal-grade timestamping — not a sidecar feature.
| Capability | BA | Stamp | OpenTimestamps | OriginStamp / OriginVault |
|---|---|---|---|
| Legal focus | ✓ Primary | General-purpose | Shifted toward AI archiving |
| Jurisdiction-aware certificates | ✓ 6+ legal systems | ✗ | Partial |
| Polygon anchor | ✓ Smart contract storage | ✗ | ✗ |
| Bitcoin anchor | ✓ Via OpenTimestamps | ✓ Primary | ✓ |
| Trustless on-chain verification | ✓ timestamps(root) | Requires archive node | Hosted verify only |
| Client-side hashing | ✓ Mandatory | ✓ | Optional |
| REST API + webhook | ✓ Pro & Enterprise | Partial | ✓ |
| Legal consulting layer | ✓ In-house | ✗ | ✗ |
We are working with a small group of law firms, notaries, and compliance teams to shape the platform. If that's you, we'd like to talk.
A blockchain timestamp is an atypical proof. In most jurisdictions, it is admissible evidence and shifts the burden of contestation onto the opposing party — they must demonstrate the anchor was tampered with, which is computationally infeasible. It is not the same as a qualified electronic signature, but for proving existence and integrity of a document at a point in time, it is robust and court-tested.
No. We compute the SHA-256 hash entirely in your browser and transmit only the 64-character fingerprint. The hash is a one-way function — your original file cannot be reconstructed from it.
The merkle root is also anchored on Bitcoin via OpenTimestamps. As long as one of the two chains survives — which is essentially guaranteed for Bitcoin — your proof remains verifiable. The verification logic is open and documented.
Yes. Every stamp has a public /verify/[hash] page. Upload the original file, and the system recomputes the hash, fetches the merkle proof, and queries the on-chain root. Any third party — including a court expert — can reproduce this verification.
No, never. We store only the hash, metadata you provide (filename, size, mime type — optional), and the merkle proof. You keep your document.
A notary-issued timestamp in the EU typically runs €50–€200 per document. BA | Stamp starts at $5 with equivalent evidentiary weight in civil matters, and is instantly reproducible across all recipients.
No credit card for the first stamp. Cryptographic certificate ready before you finish your coffee.
