A Qualified Electronic Signature is an Advanced Electronic Signature (AdES), which is further supported by an identification certificate and issued by a Qualified Signature Creation Device (QSCD). In other words, it a form of digital signature created with a qualified software, which requires users to undergo a strict process of identity validation.
Thus, for an AdES to qualify as a QES, the following must be true:
1. the digital signature must be exclusively linked to the signatory and uniquely identify them;
2. its keys must be under the exclusive control of the signatory;
3. the digital signature must be able to reveal whether it has been tampered with;
4. it must have a self-invalidating mechanism in case the document has been altered or corrupted;
To fulfill these criteria, the signature provider - that is, the software used to create the QES - must:
1. ensure only the signatory has access to the signature;
2. ensure it remains a trusted provider while it manages the signature data;
3. ensure that the signature creation data is unique, confidential and insusceptible to forgery;
As such, QES are recognized in all EU Member States.
To validate QES, PRISMA uses the software below:
https://ec.europa.eu/digital-building-blocks/DSS/webapp-demo/validation
NOTE: If your company is not in a position to provide a QES, you could ask a lawyer or a notary to validate your documents with their QES.