Signed Documents

Check a Sealed Document

When a document is signed in ProcessPlan, we seal the PDF. If anyone changes the file after that, the seal shows it. You can check the seal yourself in a few minutes with the free Adobe Acrobat Reader.

What the Seal Proves

The seal is a digital signature that ProcessPlan adds to the whole PDF when the document is signed. It covers every page, including the Certificate of Completion that follows the document. That certificate records who signed, when, and from which internet address.

  • The file has not changed. Acrobat checks the file against the seal. If the file was changed after it was sealed, Acrobat says so.
  • The time can be trusted. The seal carries a timestamp from an independent timestamp service, so nobody can change the time it was sealed, including us.

The seal belongs to ProcessPlan, not to any one signer. Each person's signature is recorded on the Certificate of Completion.

Check It in Adobe Acrobat Reader

Web browsers and most preview apps show the pages but don't check the seal. Use Adobe Acrobat Reader on a computer. It's free from adobe.com.

  1. Save the PDF to your computer and open it in Acrobat Reader.
  2. Near the top of the document, Acrobat shows a colored bar about signatures. Click Signature Panel at the right end of that bar. If there's no bar, click the pen-shaped Signatures icon in the side panel instead.
  3. Find Signed by ProcessPlan Document Seal and click the small arrow next to it to show its details.
  4. Look for “Document has not been modified since this signature was applied.” That line means the file is exactly as it was sealed.
  5. You should also see “The signature includes an embedded timestamp.”

If Acrobat says the signature has not been checked yet, right-click Signed by ProcessPlan Document Seal and choose Validate Signature.

Why Acrobat Says the Identity Is Unknown

Acrobat comes with a list of organizations it trusts. ProcessPlan's seal certificate is not on that list, so Acrobat shows a yellow warning that the signer's identity, or the signature's validity, is unknown.

That warning is about who vouches for the certificate. It does not mean the document changed. The line “Document has not been modified” answers that question on its own.

Anyone can make a certificate and call it “ProcessPlan Document Seal”, so the name alone does not prove the seal is ours. The certificate's fingerprint does.

Confirm the Seal Is Ours

A fingerprint is a long code worked out from the certificate itself. Every certificate has a different one, and nobody can make a certificate that matches ours.

  1. In the seal's details in the Signature Panel, open Signature Details and click Certificate Details.
  2. In the window that opens, click ProcessPlan Document Seal, the lower of the two entries in the list on the left. The one above it, ending in Root CA, is a different certificate.
  3. Open the Details tab and click the row named SHA1 digest. Its full value appears in the box below the list. Skip the row named SHA1 digest of public key, which is a different code.
  4. Compare it with the table below. Spaces don't matter.

If the fingerprint doesn't match, the seal is not ProcessPlan's. Don't rely on the document, and let us know.

If Something Was Added After Sealing

People sometimes add a comment, a highlight or typed text to a sealed PDF, for example with Acrobat's Fill & Sign. The sealed version is still inside the file, and Acrobat tells you what happened.

  • “This revision of the document has not been altered” means the part we sealed is unchanged.
  • “There have been subsequent changes to the document” means something was added after sealing. Acrobat lists what was added, such as a typed comment.
  • “Click to view this version” opens the document exactly as it was sealed, without the additions.

If Acrobat instead says the document has been altered or corrupted since it was signed, the sealed content itself was changed. Don't rely on that copy. Ask whoever sent it to you for the original.

Questions About a Document

Every sealed document has a document ID. It's at the top of the Certificate of Completion and in the seal stamp beside it, for example ID 7K3Q9-MXA2B.

If something on this page doesn't match what you see, contact our support team and include the document ID. For a copy of the original document, ask the person or company that sent it to you.