Integrity (of data)

Integrity is the property guaranteeing that data has not been altered or falsified after its creation, transmission, or storage. In digital signature, integrity is ensured by the hash function: any modification to the document means that the recalculated hash no longer matches the one encrypted in the signature, immediately invalidating verification. This is why a PDF signed with Certyneo is "sealed" — it cannot be modified without the signature breaking.