Sign with a certificate and check signatures

Sign

1. Choose Fill & Sign › Certificate signature and drag where the visible signature goes.
2. Choose a digital ID file and enter the Digital ID password, or Create a self-signed ID with your Name on the ID.
3. Optionally add a Reason and Location.
4. To lock the document, tick Certify (lock the document against later changes) and choose what's Allowed after certifying.
5. Save the PDF to keep the signature.

Check signatures

Open Signatures in the side panel and select Validate all. Each signature shows Valid, Invalid or Validity unknown, who signed it, when, whether the document was Changed after signing, and whether the certificate was revoked.

Validity unknown usually means the signature is intact but its certificate is self-signed or from an issuer Waraq doesn't know.