We've had two near-misses where redacted PDFs still exposed metadata. Diagnose where our redaction process fails (visu…
Open the PDF file that contains digital signatures.
Review the document to identify any sensitive or hidden data that needs to be removed.
Do not use the Sanitize Document feature, as it will invalidate all digital signatures.
CautionUsing the Sanitize Document tool removes signatures because it alters the file structure.
Instead, use the Remove Hidden Information tool: go to Tools, then select Protect, and choose Remove Hidden Information.
NoteThe Remove Hidden Information tool lets you selectively remove metadata, hidden text, and other elements without affecting digital signatures.
In the Remove Hidden Information panel, review the list of detected items and uncheck any items you do not want to remove.
Click Remove to delete the selected hidden data.
Best practiceBLOGS recommend saving a backup copy before removing hidden information, in case you need to revert changes.
Save the PDF with a new name to preserve the original signed version as a backup.
Verify that the digital signatures remain valid by checking the signature panel.
NoteRemoving hidden information using this method does not alter signed content, so signatures should remain valid.
To preserve signatures, always use Remove Hidden Information instead of Sanitize Document when cleaning hidden data.
This runs in the Acrobat app - there is no separate API for this task.
In Adobe Acrobat, you can use the 'Remove Hidden Information' tool to sanitize your PDF. However, be careful—some changes may break the digital signature. Always check the signature status after sanitizing. If you must keep the signature valid, only remove information that does not affect signed content.
A digital signature in a PDF proves that the document is from a trusted source and has not been changed since it was signed. It helps others trust that the document is real and safe to use.
You can only remove information that was not part of what was signed. If you change or delete anything that was included in the signature, the digital signature will become invalid. Always check which parts are safe to sanitize.
Sanitizing removes hidden data and metadata, like comments or past edits, while redacting covers up visible information, like names or numbers. Both help protect privacy, but they work in different ways.
A digital signature checks if any part of the signed content has changed. If sanitizing removes or changes something that was signed, the signature will no longer match and will show as invalid.