Security
Electronic seal on a PDF
July 2, 2026 · 9 min read · Docshark team
A signature image on a PDF is easy to copy. What holds up later is the seal: a cryptographic binding between the file, the signers, and the audit trail. Docshark applies a PAdES seal and hosts a public verify page anyone can check without logging in.
Signature vs seal
| Element | What it proves |
|---|---|
| Visual signature | Someone placed ink on the page |
| Audit events | Who opened, verified, signed, when |
| PAdES seal | File hash matches signed state; tamper evident |
| Public verify | Third party confirms without your account |
Verify without an account
Upload the finished PDF to the public verify flow. The page confirms the seal and document hash match. Senders, recipients, and counsel can all use the same check months later.
MSA-2026.pdf
Sequential routingReads from before the ink stay on this same envelope.
When you need third-party proof
- Finance asks if the contract they filed is the signed original
- A partner disputes which version was executed
- Audit or compliance review samples one envelope
- You need to show read + sign timeline to counsel
How sealing fits the send flow
- Tracked link records reads
- OTP ties each signer to email
- Completion applies PAdES to the PDF
- Certificate email includes verify URL
Seal your next send end to end. Start free or read certificate explained.
Questions people ask
What is an electronic seal on a PDF?
A cryptographic seal binding the signed file to recorded events. Docshark uses PAdES with public verify.
How do I verify a signature?
Use the public verify page with the sealed PDF or certificate code from the completion email.
How do I seal a PDF electronically?
Applied automatically when all signers finish on Docshark. Download sealed export or verify online.
Can anyone verify?
Yes. Public verify does not require a Docshark login.
What if the file is edited after seal?
Verify fails or shows tamper. The hash no longer matches the sealed record.
Is seal included on free?
Yes. PAdES seal and public verify on completed envelopes at every plan tier.
Audit certificate vs sealed PDF?
Sealed PDF is the signed document. Certificate is the event log; both link to verify.
Gulf contracts?
Same seal flow for Arabic or English PDFs. Legality context on our country pages.