How to
Prove a signed agreement has not been altered
Somebody outside your business — a client, an auditor, a lawyer — can confirm the file you handed them is exactly the one that was signed, and that it existed by a certain date.
- 1
Open the completed agreement and download two files: the signed PDF, and the attestation packet that goes with it.
Documents · agreements → open the document → download attestation packet
The packet emailed to signers the moment signing finished is the early copy, taken before the timestamp settles. Download a fresh packet from the document if you want the bitcoin anchor in it.
- 2
Send both files to whoever needs to check them. The completed-signing email also carries a one-click verification link you can forward instead.
Documents
The one-click link shows a redacted result — signer names, titles, and signing times, never their email addresses or IP addresses.
- 3
They open the public verify page, paste or upload the attestation packet, and add the signed PDF.
Documents · agreements → verify
Leaving the PDF out is the mistake worth avoiding. Without it the page can only say the packet itself is genuine — it never checks the file in their hands, and that is not a pass.
- 4
Read the three checks: the signature over the document, the document's own fingerprint, and the bitcoin anchor with the block it landed in.
The anchor is not instant. It settles on a daily sweep, so allow about a day after signing before a block number is there to show.
- 5
When somebody wants a check that trusts nothing of ours, point them at the open-source verifier named on the verify page. It runs the same checks on their own machine against our published signing key.
Documents · agreements → verify
Worth knowing
- What this proves is that this exact file, unchanged, existed no later than the anchored block — not who the signers were. It is evidence about the document, not identity verification.
- An agreement signed somewhere else and imported carries no signing certificate. What is recorded is the fingerprint of the file that was uploaded and who uploaded it: evidence of custody, not of a signing ceremony.
- The verify page keeps nothing. It checks what it is handed and stores no copy, which is why the person checking needs the files rather than an account.