How to Understand Acrobat Messages About Valid Digital Signatures
Question details
The user wants to understand the meaning of Adobe Acrobat messages that confirm a digital signature is valid while also noting that the document was updated or changed after signing.
- Product
- Device & OS
- not provided
- Scenario
- Reviewing a digitally signed PDF document to verify its integrity and authenticity.
- Observed behavior
- The PDF viewer displays a message confirming the signatures are valid alongside a notice indicating that changes or updates were detected after the signature was applied.
Ensure you have the signed document open in a reliable PDF viewer, and avoid making any unintentional edits or form inputs before reviewing the signature details.
Review Post-Signing Changes via the Signature Panel
Inspect the document version and change history in the Signature panel to determine if post-signing modifications were authorized.
A message stating a signature is valid simply means the cryptographic signature can be validated by the software. However, a notice that the document was updated requires you to review what exactly was changed. Some changes, like filling out subsequent form fields, are typically permitted, while unauthorized text edits may invalidate the document's intent.
Locate the Signature panel on the left side of your PDF viewer (such as Adobe Acrobat or Acrobat Reader). If the panel is not visible, right-click the left-hand icon area and select 'Signature panel' from the context menu.
Expand the signature details within the panel to view the document's version history and the specific changes recorded since the signature was applied.
Review the listed changes to determine whether they were permitted actions (such as standard form completion) or unauthorized edits. Verify these changes against your organization's approval requirements.
Validate and Review PDF Signatures Easily in WPS Office
WPS Office provides a comprehensive, lightweight PDF toolkit that allows you to effortlessly view, validate, and manage digital signatures, ensuring your document's security and integrity.
- 1. Open Your PDF: Launch WPS Office and open the digitally signed PDF document.
- 2. Access the Protect Tab: Navigate to the 'Protect' tab on the top ribbon to access the suite of PDF security features.
- 3. Verify Signatures: Click on 'Manage Signatures' or view the signature details to validate the cryptographic signature and review the document's integrity.
Frequently Asked Questions
Why does it say my document was updated after signing?
This message appears if any changes were made to the PDF after the digital signature was applied. This can include harmless actions like filling out form fields, adding comments, or signing additional signature fields, as well as unauthorized text or layout edits.
Does an 'updated after signing' message mean the signature is invalid?
Not necessarily. If the signature has a green checkmark, the cryptographic signature is still valid for the version of the document as it existed when signed. However, you should review the Signature panel to ensure the subsequent changes were authorized and do not alter the document's intent.
How can I prevent a PDF from being changed after I sign it?
When signing a PDF, you can usually select an option to 'Lock document after signing' in your PDF software. This restricts any further edits, annotations, or form filling, preserving the document's exact state and preventing 'updated after signing' warnings for future viewers.
