Verify Document
Upload a SimplSign PDF to verify its timestamp certification.
About Timestamp Certification
SimplSign uses FreeTSA.org to provide RFC 3161 timestamp certification. This creates cryptographic proof of when a document was signed, which cannot be altered.
Offline Verification
You can verify the timestamp offline using OpenSSL and FreeTSA's public certificates:
- Download FreeTSA certificates from freetsa.org
- Extract the TSR from the PDF metadata
- Verify using:
openssl ts -verify -in response.tsr -queryfile request.tsq -CAfile cacert.pem -untrusted tsa.crt
What is Timestamp Certification?
Timestamp certification provides cryptographic evidence that a document existed at a specific point in time. When you sign a document with SimplSign, a SHA-256 hash of the document is submitted to FreeTSA, a trusted third-party timestamp authority.
FreeTSA returns a signed timestamp token that is embedded in the PDF. This token can be independently verified using FreeTSA's public certificates, proving that the document has not been modified since the timestamp was created.