PDF problem
Signature invalid after editing a PDF
SymptomA PDF reader shows the signature as invalid, or warns the document changed after it was signed.
Why it happens
- •The PDF was edited after a certificate based digital signature was applied.
- •The file was re saved in a way that rewrote signed bytes.
How to fix it
Edit before signing
Make all changes first, then sign. Signatures are meant to detect changes.
Ask for a new signature
If the document must change, the signer needs to sign the new version.
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Open Sign PDFQuestions people ask
+Do electronic signature images have this problem?
Image signatures don't cryptographically seal the file, so they aren't invalidated, but they also don't prove the document is unchanged.
+Can I remove an invalid signature?
Better to go back to the unsigned version and sign again.
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