Frequently Asked Questions
Everything you need to know about NUBSEAL and how digital document verification works.
Server-based verification is an advanced method that cryptographically fingerprints the full PDF and issues a QR containing a digital file fingerprint (Digital Hash). A reference copy is stored on secure servers. When someone scans the QR and submits the file, the current fingerprint is matched against the server reference to detect any change, even tiny edits, making forgery effectively impossible.
One seal is deducted only when a new file is successfully sealed through the dashboard or API. Verification operations are completely free for everyone and do not consume the customer's seal balance.
That attempt will fail. Verification is not based on QR alone; it inspects deep PDF metadata and signatures. If the file is recreated from scratch, the system marks it as an invalid copy. If textual content is altered, it flags the document as tampered.