2 steps to verify a proof
Open a file
Choose any file from your device. We only read it locally in your browser to calculate its fingerprint.
Files are never uploaded.
Review existing proofs
2 steps to verify a proof
Open a file
Review existing proofs
Review any existing verified proofs for this file.
To add your own proof, install the app.
This proof is written to the public record and cannot be edited or removed. Anyone with the original file can independently verify it.
Only someone with the original file can decrypt and read this message.
Save or print a certificate for this verified file.
Date of certificate
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Document
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Public document ID
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Signatures
Document verified
This certificate confirms the listed signer(s) were in possession of the document on the stated date using a cryptographically secure OpenSig identity. It proves the document existed at that moment and has remained unchanged since.
Verification instructions
Alternatively, visit opensig.net/verify to regenerate the certificate instantly.
Issued by opensig.net — Secure digital signatures on the blockchain.
This preview matches the certificate inside the OpenSig mobile app.