A signature you can still prove, years from now.

SenseBeen Sign issues a timestamped, content-addressed receipt with every signature and records it on the Proof Ledger.

Shipping today

LIVE

Signing runs on DocuSeal; every completed document is fingerprinted, co-signed and filed back into your SenseBeen Cloud vault automatically.

Timestamped receipts

Every signature carries a precise, verifiable time of signing.

Metadata in the PDF

Verification metadata is embedded directly in the signed document.

A ledger entry per signature

Each signature writes a record to the Proof Ledger.

In testingIN TESTING

Signatures that outlast the math they rely on.

Hybrid signing pairs a classical signature with , the lattice-based signature scheme standardized as NIST FIPS 204. A document carries both, so it stays provable even after quantum computers break the classical scheme.

To be clear: hybrid signing is in internal testing ahead of general release. It is not yet the default, and we are validating it against real documents before we turn it on for everyone.

When a document requires it, the signer's ID is checked by Veriff through DocuSeal. The public ledger records only hashes and signatures, never signer identity details.

Classical and post-quantum signatures are applied together, never one in place of the other.

Sample receipt

Document: sample-agreement.pdf
Signer: signer@example.com
Timestamp: 2026-XX-XX 00:00:00 UTC
SHA-256: (sample)
Document signature: DocuSeal PDF signature
Ledger co-signature: IN TESTING

Why it matters

Sign now, forge later

Once a quantum-capable adversary can recover a classical private key, it can produce signatures that verify as genuine, and a classical-only signature can no longer prove who signed. A post-quantum co-signature keeps the original signature provable.

Signed today
Stored for years
Classical key broken
PQ signature still holds

Post-quantum public key

IN TESTING

algML-DSA-65

key_idc926b95f902d382b

public key (base64)

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

Also available as JSON at /api/ledger/pubkey. Retired keys stay published at /api/ledger/pubkeys.

Verify a signed document

Drop a signed PDF into the verifier. It is hashed with SHA-256 in your browser and checked against the Proof Ledger, so nothing is uploaded.

Open the verifier

Join the pilot

Help us validate hybrid signing against real documents ahead of general release.

Request a signature Join the pilot