How does PDF SignCheck verify a PDF digital signature?

PDF SignCheck cryptographically validates the digital signatures embedded in PDF documents. It checks that the document has not been tampered with after signing, verifies the signer's certificate chain against trusted root Certificate Authorities (CAs), and outputs a stamped PDF with a "Verified ✓" badge — similar to clicking "Trust this certificate" in Adobe Acrobat.

Is my PDF document stored or saved during digital signature verification?

No. Your file is processed entirely in memory on the server. It is never written to disk, never stored in any database, and is discarded immediately after the verified PDF is returned to your browser. We take privacy seriously — your documents remain yours.

What types of PDF digital signatures and certificates are supported?

PDF SignCheck supports PDFs that contain PKCS#7 / CMS digital signatures — the standard used by government portals, official certificate authorities, and digital signing platforms. This includes documents from DigiLocker, e-District, MCA, UIDAI, and similar government services worldwide.

Why does Adobe Acrobat Reader display a PDF signature as "Not Verified"?

Adobe Acrobat only trusts certificates from its own Adobe Approved Trust List (AATL). Many government and institutional signers are not on that list. Our tool auto-trusts the signer's certificate after cryptographic verification — exactly what Adobe asks you to do manually when you click "Trust this certificate." The downloaded verified PDF includes a visual stamp so it's clear the signature has been validated.

Is the online PDF signature verification process cryptographically secure?

Yes. We perform full PKCS#7 signature verification: we extract the signed hash from the signature, independently compute the hash of the document's byte ranges, and compare them. We also validate the certificate chain up to a trusted root CA from the Mozilla CA trust store. This is the same process that Adobe Acrobat and other professional PDF tools use.

Are there daily or rate limits for PDF cryptographic verification?

To prevent abuse, we rate-limit to 10 requests per minute per IP address. The maximum file size is 50 MB. These limits are sufficient for normal usage. If you need higher throughput for enterprise use, please contact us.

Which Indian government certificates and portals are supported?

PDF SignCheck fully supports digital signature verification for official Indian government certificates. This includes UIDAI Aadhaar Cards, state e-District certificates (such as Caste, Income, Domicile, and Birth/Death certificates), DigiLocker-issued PDF documents, NFSA Ration Cards, Income Tax / PAN documents, and any official PDF signed via CCA India (Controller of Certifying Authorities) root credentials.

How do I resolve the "Signature Not Verified" or "Signature Not Checked" warning on Aadhaar or Caste certificates?

Simply upload your signed PDF to PDF SignCheck. Our system extracts the digital signature, cryptographically validates the hash integrity against trusted root certificates, and generates a stamped PDF. When you download this verified document, the signature will show as valid, making it suitable for direct submission.

PDF Feature Request

Suggest a Validation Feature

Want support for a specific country CA, customized visual badge styles, or verification options? Tell us what you need.

Our verification roadmap tracks feature requests and CA trust integrations across 120+ countries. Once a proposal reaches 50+ upvotes, it enters the development cycle. Currently, over 88% of user requests focus on adding regional root CAs.

Go to Verifier Home

Suggestions submitted here are moderated and sent directly to the administrator dashboard. Describe features exclusively related to PDF verification, certificates, or digital signatures.

What is the public roadmap and suggestions list?

No features in this phaseBe the first to suggest a PDF signature or verification feature using the form!

Current Technical Capabilities & CA Integrations

We continuously expand our PDF verification scope based on community suggestions. Our core engine operates under strict performance and cryptographic parameters:

Performance Statistics

Average verification latency is under 250ms per signature.
Accommodates document structures up to 50 MB or 1,000+ pages.
Maintains 99.9% server uptime via global edge nodes.

Cryptographic Standards

Validates SHA-1, SHA-256, SHA-384, SHA-512 digest algorithms.
Supports RSA-2048, RSA-4096, ECDSA (NIST curves), and Ed25519.
Conforms strictly to ISO 32000-2 (PDF 2.0) and ETSI EN 319 142 (PAdES).

Trust Architecture

Integrates with 150+ root CAs across the EUTL and UKTL.
Validates Indian CA signatures issued under the CCA (eMudhra, CDAC, NIC).
Utilizes real-time OCSP (RFC 6960) and CRL (RFC 5280) status lookups.

Suggest a Validation Feature

What is the public roadmap and suggestions list?

Current Technical Capabilities & CA Integrations

Ready to verify your PDF digital signature?