Verifying a signed PDF
Anyone can check that a PDF is exactly the file a completed AutomaDoc Sign request delivered, with
no account: a signer, a lawyer, an auditor, the office you sent a signed form to. Open the verify
page, www.automadoc.cc/en/verify (in any of the seven languages: /es/verify, /id/verify
and so on), and drop the PDF on it, or click to choose it.
How it works
Section titled “How it works”- Your browser reads the file and computes its SHA-256 fingerprint on your device (“Computing the fingerprint…”). The file itself is never uploaded.
- Only the fingerprint, 64 hexadecimal characters, is sent to AutomaDoc (
POST /api/verify). - AutomaDoc looks for a completed request that delivered a file with that exact fingerprint.
The page shows the file’s fingerprint under the answer, match or not, so you can keep it with your records.
What a match tells you
Section titled “What a match tells you”“This PDF matches a completed signature request.” The answer shows three things and nothing else:
- Request: the request’s ID, the one printed on its certificate;
- Completed: when the request was completed;
- Signers: how many people signed.
No title, no names, no email addresses and no document content are shown, so the page reveals nothing about a request to someone who does not already hold its file.
A match means the file is byte for byte the one AutomaDoc delivered when the request completed. The certificate of completion with the same request ID says who signed and when.
Which files match
Section titled “Which files match”The fingerprints checked are those of the files a completed request delivers:
- each signed document, as delivered: stamped with the signatures, with the certificate of completion at the end when the sender appended it;
- all documents in one PDF, for a request with two or more documents.
The original file and the document sent for signature are not delivered files, so they never match, and neither does a request that was declined, voided or expired. The certificate prints the fingerprint of the signed document before the certificate was added, because a file cannot contain its own fingerprint: when the certificate is appended, that printed value differs from the delivered file’s fingerprint, which is the one this page checks.
No match
Section titled “No match”“No completed signature request matches this file.” The usual reason is that the file changed. Any change gives a different fingerprint: one character, a filled form field, a comment, even opening the PDF and saving it again unchanged, since most programs rewrite the file when they save. Use the file exactly as it was delivered: the email attachment or the download, not a copy someone opened and saved.
A printed and scanned copy never matches.
Limits
Section titled “Limits”- The check is rate limited per IP address; past the limit the page says “Too many checks in a short time. Wait a minute and try again.”
- Files over 200 MB are refused before anything is computed: no file AutomaDoc Sign delivers is that large.
- A file you sign with Sign it myself is checked the same way.