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.

Trust & Transparency

Editorial & Security Policy

Last updated: July 2026

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Our Commitment to Accuracy

At PDF SignCheck, every technical guide, verification tool specification, and legal breakdown is thoroughly researched and reviewed against established cryptography standards (RFC 5652, ETSI PAdES, ISO 32000) and statutory regulations (IT Act 2000, EU eIDAS, US ESIGN Act).

1. Authorship & Subject Matter Expertise

All articles, guides, and tool documentations published on PDF SignCheck are written and maintained by Minhaj (Founder of PDF SignCheck) along with cybersecurity engineers.

We do not use auto-generated low-quality text or unverified summaries. Every workflow step for verifying e-District portals, DigiLocker certificates, UIDAI signatures, and international e-Signatures is manually verified on real signed PDFs before publication.

2. Technical Verification Standards

Our guides and verifiers align strictly with official RFC specifications and international security norms:

PKCS#7 / CMS (RFC 5652): Cryptographic parsing of signature dictionaries and byte ranges.
ETSI EN 319 142 (PAdES): PDF Advanced Electronic Signatures validation rules.
Mozilla CA Trust Store: Checking certificate validation chains against 80+ globally trusted root authorities.
CCA India Root Store: Trust chain validation for Indian Certifying Authorities (NIC CA, eMudhra, Capricorn, CDAC, Pantagon Sign).

3. Privacy & Data Security Standards

Security is integral to our editorial philosophy. When creating tools and tutorials, we enforce strict zero-retention principles:

Files are never written to disk or permanent databases.
All cryptographic calculations occur in isolated volatile memory.
Temporary memory blocks are immediately discarded after returning verified PDFs.

4. Corrections & Updates Policy

As government portals, Certifying Authorities, and browser PDF engines update their root lists or UI interfaces, we update our guides to maintain 100% accuracy.

If you identify an outdated step, broken portal link, or technical typo, please reach out to us at hi@pdfsigncheck.com. Corrections are typically reviewed and published within 24 hours.