Validate digital signatures on any PDF with confidence.
The Signature Validator analyzes the internal structure of a PDF to detect embedded digital signatures, encryption, incremental updates, and cryptographic integrity. It works with documents from any platform, including Adobe Acrobat, DocuSign, and SignFortress.
Key Features
Detects standard PDF digital signatures (/ByteRange + /Contents)
Performs full cryptographic validation when possible using OpenSSL
Smart encryption detection with password prompt only when required
Supports encrypted SignFortress .enc files
Displays the full PDF in-browser for visual confirmation
Temporary files auto‑purged after ~10 seconds for privacy
Manual purge option for immediate cleanup
Handles complex PDFs with incremental updates and multiple revisions
How to Use
Upload a PDF or .enc file
Enter a password only if prompted
Click “Validate Signature”
Review the validation result and PDF preview
Optionally purge temporary files immediately
Result meanings: Valid digital signature means the signature was cryptographically verified Signature detected means the signature structure exists but may not be fully extractable Invalid or corrupted means the signature or PDF structure failed validation
Troubleshooting Tips
If validation fails, open the PDF in Adobe Reader to confirm integrity
For encrypted PDFs, ensure the correct password is used
Large or complex PDFs may take longer to process
Try re‑saving the PDF if it was exported from a non‑standard tool
Frequently Asked Questions
Is my document safe when using the Signature Validator?
Yes. Files are processed securely and automatically deleted within seconds. Nothing is stored or shared.
Can I validate documents from other platforms?
Yes. The Signature Validator works with PDFs from Adobe Acrobat, DocuSign, HelloSign, and any tool that embeds standard digital signatures.
What does “Signature detected” mean?
It means the PDF contains a valid signature structure, but full cryptographic extraction may not be possible depending on how the PDF was created.
Why am I being asked for a password?
The PDF is encrypted. The validator only prompts for a password when absolutely required to read the signature data.
What are .enc files?
These are encrypted SignFortress files. They always require a password to validate.
Privacy & Security Notice
Your document is private and secure.
No file is stored permanently. All files are automatically deleted within seconds after viewing.
All processing happens on this server only, and nothing is sent to third parties.
Use this tool to independently verify digital signatures on documents received via SignFortress.
Supports standard PDFs and encrypted SignFortress .enc files.
Or drag and drop a PDF or encrypted .enc file here
PDF is Password Protected
This PDF is encrypted. Please enter the password to continue validation.
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