Electronic signature

Under eIDAS, an electronic signature has three levels - simple, advanced (AES) and qualified (QES) - each with different legal effect and use case.

Under eIDAS, an electronic signature is data in electronic form attached to or logically associated with other electronic data, used by the signatory to sign. The signatory is always a natural person; when an organisation itself signs data, this is called an electronic seal. The definition is deliberately broad: a typed name, a scanned signature or a click can all be a (simple) electronic signature. In everyday language, "digital signature" is often used as a synonym, but strictly it is the cryptographic technique (a hash encrypted with a private key) that underlies advanced and qualified electronic signatures - a technical building block, not the broader legal concept.

eIDAS distinguishes three levels: simple, advanced (AES) and qualified (QES). The levels differ in how strongly the signature is linked to the signer and protected against tampering, and in legal effect. An electronic signature may not be denied legal effect solely because it is electronic, but only the qualified level is automatically equivalent to a handwritten signature. In the Netherlands, article 3:15a of the Civil Code (BW) gives a qualified electronic signature the same legal effect as a handwritten one outright; for an advanced or any other electronic signature that effect depends on whether the method used was sufficiently reliable for the purpose and the circumstances. Under eIDAS 2.0, the EUDI Wallet will let citizens create qualified electronic signatures free of charge for non-professional use.