Certify integrity,
date and provenance
What?When?Who?
or capture
Your file never leaves this device.
Your certificate is ready.
Add to my certificates on this device
Stores, only in this browser, the useful information (date, name, fingerprint, type, ID) to reopen this certificate later.
Strictly local storage. DfinA receives no copy. The list may disappear if you clear the browser data, change device, use another browser or uninstall the PWA.
SHA-256 and SHA3-512 fingerprints
Computed locally · Secure and tamper-proof
Permanent verification
Anytime, anywhere in the world
Multiple certification
included in unlimited plans
Digital seal
included in unlimited plans
Option Premium
Anchoring on the Bitcoin blockchain
+
How it works
1. Drop
your file
2. Fingerprint
generated locally
3. Certificate
ready to keep
My certificates
Your vault
0sealed proofs
—protected
—your first proof
0this week
This list is stored only on this device and in this browser. DfinA holds no copy of it. It may disappear if you clear the browser data, change device, use another browser or uninstall the PWA.
Verify a certificate
Simple method: Drop the certificate and the file to verify in the boxes below
The file is never sent. Comparison is done in your browser.
Advanced independent verification: you can also verify the blockchain anchoring with the open OpenTimestamps tools, without depending on DfinA Vault.
Settings
DfinA keeps nothing server-side. You fully control the data saved on this device.
Private by design. No file, no certificate and no history is stored by DfinA. The only data that can exist is the optional list you save yourself, locally, in this browser.
Certificates saved on this device
0 certificate(s) stored locally
Automatic saving
Keep every certificate in “My certificates”, on this device
Erase the certificates on this device
Permanently deletes the local list. Irreversible action.
Help & ressources
FAQ, terms and independent verification
DfinA Vault · Proof. Integrity. Trust.