FAQ

Last updated:July 8, 2026

Common questions about WPS Validate Signature usually involve signature status, post-signing document changes, and signer identity checks; this FAQ includes 3 common questions and a glossary.

FAQ

How to validate digital signature in PDF when the result shows "Unknown"?

  1. Click the signature area first and review the certificate information.
  2. Check whether the current device trusts the related certificate.
  3. Run Validate Signature again and review the result in the bottom status bar.
  4. If the status still shows unknown, contact the signature provider to confirm whether the certificate is complete and valid.

What happens if the document is changed after signing?

  1. Open the document and run Validate Signature.
  2. Review the validity status in the validation result.
  3. If the document was changed after signing, the signature may appear invalid or the result may indicate an integrity issue.
  4. It is recommended to request the original signed file again.

How do I confirm the signer identity?

  1. Click the signature area in the document.
  2. Review the signer information in the signature details panel.
  3. Check the certificate information and signing time at the same time.
  4. Use the validation result to decide whether the signer identity information is trustworthy.

Glossary

TermDefinition
Digital signatureAn electronic signing method used to confirm signer identity and protect document integrity.
Certificate informationThe digital certificate details attached to a signature, used to review signer identity and trust status.
ValidityWhether the signature is judged to be valid under the current verification conditions.
Document integrityWhether the document has remained unchanged after signing.