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.

Legal Agreements

Privacy Policy

Last updated: June 24, 2026

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Our Core Privacy Promise

PDF SignCheck is built from the ground up as a privacy-first utility. We do not save, store, sell, or analyze your uploaded PDF documents or camera scans. All cryptographic calculations and barcode/QR scans occur strictly in volatile system memory or locally on your device, and are immediately discarded.

1. What information do we collect?

To provide you with our secure digital certificate checking tools, we collect the minimum necessary data:

Uploaded & Password-Protected Files (Zero Retention): When you upload a PDF document for signature validation or barcode extraction, the file is temporarily loaded in-memory on our secure servers, programmatically inspected, and immediately discarded after returning the results. For password-protected documents (such as encrypted government IDs), you may enter the document password which is securely processed in-memory solely to enable local decryption and barcode extraction; neither your password nor the decrypted document bytes are ever written to persistent disk or storage.
Camera & Scan Data (Zero Retention): When you use the mobile application's camera scanner to read QR codes or barcodes from physical documents, the camera feed and capture processing are executed entirely offline and locally on your mobile device using native machine learning. No video feeds, images, or document contents from your camera are ever transmitted, uploaded, or stored on external servers or APIs.
Account Information: If you register or authenticate an account (including Google OAuth sign-in), we store your email address, name (if provided), and account credentials. This authentication is managed securely in partnership with Neon Auth.
Payment Data: Payment processing is handled entirely by Dodo Payments. We do not store or process your credit card numbers, billing addresses, or specific payment credentials on our systems.

2. How do we use your information?

We use collected information solely to support the active features of PDF SignCheck:

To inspect and stamp cryptographic validity badges on your requested PDF files in real-time.
To track daily rate limits associated with your account tier and top-up credits.
To send transaction receipts, password reset links, and critical security update notices.

3. Do we use cookies and analytics?

We use secure, standard HTTP-only cookies to handle user authentication state sessions. These cookies do not track your activity across external web spaces.

4. What third-party integrations do we use?

We partner with select trusted services to deliver the platform infrastructure:

Neon Auth: Provides passwordless login, database encryption, and security credentials management.
Google Cloud Platform: Facilitates Google Account OAuth logins to save you from typing passwords.
Dodo Payments: Handles PCI-compliant billing pipelines and invoice receipts securely.

5. How is data retention and security handled?

We apply modern industry-standard transport level encryption (SSL/TLS) for all data transfers. File inspection blocks run inside isolated server environments with no persistent storage volumes attached. Account records are kept securely until you request account deletion.

6. How can you contact us regarding privacy?

For questions regarding this policy, to request account deletion, or to submit feedback, contact us at: hi@pdfsigncheck.com