Sign Officially
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Verify

Is this document genuine?

Drop a PDF signed with Sign Officially. We calculate its fingerprint on your device and check it against our sealed records. The file is never uploaded.

Drop the signed PDF here

Or choose it from your device.

How verification works

  1. Your browser calculates the SHA-256 fingerprint of the file.
  2. We look up that fingerprint, and return the sealed record if we have one.
  3. Your browser checks our Ed25519 signature on that record with our published public key.
  4. If even one byte of the PDF changed, the fingerprint will not match.

Questions

It says no record was found

The file is not the final copy we sealed. It may have been changed, printed and scanned, or re-saved by another program, or it was signed with another service.

Can I check without trusting Sign Officially?

Yes. The seal is a standard Ed25519 signature over a JSON record. Our public key is at /.well-known/signofficially-seal.json and any Ed25519 library can check it.