Why does my PDF show 'Signature Not Verified'?

It usually means your PDF reader does not trust the Indian CCA root certificate that issued the signing certificate. The document is typically genuine; the reader simply cannot build a trusted chain. Importing the CCA root, or using an online verifier that already trusts CCA roots, resolves it.

Does 'validity unknown' mean the document is fake?

No. 'Validity unknown' is a trust message, not an integrity failure. A tampered file shows a stronger red error saying the document was altered. Unknown simply means the root certificate is not trusted yet.

How do I fix it in Adobe Reader?

Open Signature Properties, click Show Signer's Certificate, go to the Trust tab, Add to Trusted Certificates and enable 'Use this certificate as a trusted root', then Validate Signature again.

Fix "Signature Not Verified" in a PDF

Updated August 2026 · ~4 min read

If Adobe Reader shows "Signature Not Verified", "At least one signature has problems", or "Signature validity is unknown" on your Aadhaar, PAN, GST, ITR or DSC-signed PDF — don't panic. In the vast majority of cases the document is completely genuine. Here's exactly what the message means and how to fix it.

Why this happens

Every Indian digital signature chains up to a root certificate published by the Controller of Certifying Authorities (CCA). Adobe Reader ships trusting a global list (AATL) but does not trust the Indian CCA roots by default. So when it can't connect your document's signer to a root it already trusts, it honestly reports "validity unknown". This is a trust gap, not proof of tampering.

Key distinction: "Validity unknown / not verified" = the root isn't trusted yet.
"Document has been altered or corrupted" = the file was actually changed. These are very different — only the second is a real red flag.

The 30-second fix: verify online

The fastest fix is to check the file with a validator that already trusts every CCA India root:

Open our PDF verifier.
Upload the signed PDF (enter the password if it's an e-Aadhaar).
Read the verdict. A Green result confirms the signature is valid and trusted — even though Adobe showed "unknown".

This proves the document is genuine without changing any settings on your computer.

The permanent fix in Adobe Acrobat Reader

To make Adobe itself show the green tick from now on, trust the signer's root:

Open the PDF in Adobe Acrobat Reader.
Click the Signature Panel, right-click the signature, choose Show Signature Properties.
Click Show Signer's Certificate….
Go to the Trust tab → Add to Trusted Certificates….
Tick "Use this certificate as a trusted root" and confirm.
Back in the document, right-click the signature → Validate Signature. It should now show valid.

Even better: import the official CCA India root once so all government PDFs validate. Download the root from the CCA repository at cca.gov.in and add it via Edit → Preferences → Signatures → Identities & Trusted Certificates → Trusted Certificates → Import.

Common causes checklist

CCA root not trusted — the #1 cause; fixed by the steps above.
Opened in a browser or basic viewer — only full readers evaluate signatures; open in Acrobat.
Old Acrobat version — update to the latest Reader.
Certificate expired or revoked — legitimately shows a warning; our verifier will tell you which.
File genuinely edited/re-saved — if any tool re-saved the PDF after signing, the signature breaks. This is a true red result.

Not sure if it's a trust issue or real tampering?

Upload it — we tell you plainly, in seconds, for free.

Check my PDF