What a valid signature tells you
- Who signed: the name on the signer's certificate
- That the certificate was issued by a trusted, licensed Certifying Authority
- That the certificate was valid and not revoked when the document was signed
- That the document has not been changed since it was signed
Common warning signs
- "Validity unknown": the issuer is not trusted on your computer yet
- "Document has been modified": the content changed after signing
- Expired or revoked certificate at the time of signing
Checking in a PDF reader
Most PDF readers show a signature panel. Open it to see the signer, the certificate details and the validity status. Indian certificates chain up to the root certificate of the Controller of Certifying Authorities (CCA).
Coming soon
An online tool to upload a signed document and get a plain-language verification report.