Why verify at all
A digital signature is only useful if the person relying on it can check it. Verifying a signed document tells you three things with confidence: who signed it, whether their certificate was genuine and valid at the time, and whether the file has been touched since.
What a valid signature confirms
- **Who signed** – the name on the signer's certificate.
- **A trusted issuer** – the certificate traces back to a Certifying Authority licensed by the CCA.
- **Still valid then** – the certificate was not expired or revoked when the document was signed.
- **Unchanged** – the content has not been modified after signing.
How to check in a PDF reader
Most readers show a signature panel. Open it to see the signer, the certificate chain and the validity status. Indian certificates chain up to the root of the Controller of Certifying Authorities (CCA), so once that root is trusted, a genuine signature shows as valid.
Reading the warnings
- **"Validity unknown" / not verified:** the issuer is not trusted on your machine yet — not proof of a fake.
- **"Document has been modified":** the file changed after it was signed.
- **Expired or revoked:** the certificate was not in good standing at signing time.
Validating online
A quick online check can confirm a certificate's status and the signature's integrity without installing anything. We are building a tool where you upload a signed document and get a plain-language report: valid, who signed, and whether anything changed.
For businesses
If you receive many signed documents — contracts, invoices, filings — verifying them consistently protects you from forged or tampered paperwork.