Public verification
Enter the certificate code: printed on the PDF, or encoded in its QR. You will see existence, integrity hash and the public blockchain transaction. Never names, never contents. No account, no trust in us required.
Check 01
The certificate code corresponds to a real, sealed evidence package registered on C-NDA.
Check 02
The SHA-256 hash shown is the fingerprint of that package. Anyone holding the evidence ZIP can recompute it locally and compare: the maths does not need our word.
Check 03
The hash is anchored on Polygon with a public transaction. The link opens the blockchain explorer: the record is outside our control.
Verification without trust: the check is a canonical hash (RFC 8785 + SHA-256) compared with a public blockchain record. It needs nothing from us: a SHA-256 command on your machine and any block explorer are enough.
They answer the same question: is this evidence the evidence that was certified, and when was it sealed. What changes is how much of the check goes through us.
01
Type the code above. You get existence, the fingerprint of the evidence package and a link to the anchoring transaction. Fastest, and the only one of the three that asks anything of us.
02
The evidence archive contains evidence.json already in canonical form. A single SHA-256 of that file is the fingerprint, and it must match the one printed on the certificate. No account, no network, no software of ours.
03
Open the anchoring transaction on any block explorer and read the Anchored event. If the fingerprint you computed is in it, that record existed at that block, and the fact does not depend on C-NDA existing at all.