Proof, compliance and data
Electronic signature
An electronic signature links a document to its signatory and guarantees its integrity; a qualified one is equivalent to a handwritten signature.
The eIDAS regulation distinguishes three levels: simple, advanced and qualified. Only the qualified signature, based on a qualified certificate and a secure device, enjoys a presumption of reliability. For the others, whoever relies on them must prove the process is reliable. An image of a signature pasted onto a PDF is not an electronic signature.
Why it matters for fax
A handwritten signature reproduced by fax remains the image of a signature: on its own, it proves neither the sender's identity nor the document's integrity. An electronic signature answers both questions, which is why it replaces fax in many procedures.